Nyquist sampling and temperature measurements [original paper]
raylopez99
are so stunted it's pitiful.
What is the highest frequency of temperature changes on earth, at which
one should sample at least twice this highest frequency, in accordance
with the Nyquist sampling theorem, to avoid aliasing?
If none of the above makes sense, I suggest you do some background
research first.
For the handful of the rest of you that actually know what I am talking
about, I will posit this: the highest frequency is probably every 10
minutes (or more precisely one over this number). I am basing this on
intuition, as I have noticed when a cold front comes in, it takes about
that much time for a dramatic drop in temperature to result. So
temperature measurements should be taken at least every 5 minutes.
But I doubt that temperature is measured, by satellite or otherwise,
every 12 hours, much less every 5 minutes.
Now some doubters might say: "Ray, you dimwit, we are not trying to
model _weather_ changes, but _climate_ changes, which have a period
measured in years, not minutes". To this I say: baloney. Weather and
climate are part and parcel the same thing. If you measure less
frequently, thinking you are measuring long term 'climate', you run the
signficant risk of aliasing. See this Java webpage for a demonstration
of aliasing when you violate the Nyquist sampling theorem, which is a
mathematical construct:
http://www.dsptutor.freeuk.com/aliasing/AD102.html
For you mathematically challenged so-called "scientists" (earth
scientists, which to me gives the image of somebody sucking on a bong),
I will reduce the dangers of aliasing to words:
the analogy is to picture a band between two numbers, say 20 to 30,
extending horizontally, so Y1=20 and Y2 = 30. Draw a series of
'zig-zag' sawtooth lines, as many as you can fit without the lines
crossing, between these two numbers. These lines represent temperature
changes. What is the "average"? It is clearly 25. Is the temperature
increasing? No, it is range bound between 20 and 30. Now consider
what happens if you sample along the x-axis without sampling at twice
the highest frequency--in other words if you sample 'too slow'. You
will sample one point at say 21. Then, a 'long' time thereafter you
will sample again, and say you sample another point 26. Then, even
later, you sample another number, say 29. Let's stop there. You draw
a curve connecting your sample points, and, lo and behold, you conclude
'temperature is increasing from 21 to 29! We have global warming!!
STOP THE WORLD!!!'
What did you do wrong? You fell victim to aliasing. Of course I chose
the example where temperatures appeared to be increasing, but it could
also have appeared to be decreasing. The point is that because your
sample rate was too low, your sample is not representative of what you
are trying to measure.
If there was any money in Earth Science I could have just earned a
Nobel. Instead, I'll leave it to you idiots to come to the same
conclusion--maybe a decade from now.
And another bonus if you've read this far: remember "asbestos in our
schools?" How we had to remove any asbestos or it would cause
mesothelioma? A minority of scientists said to leave the asbestos in
place, as it would not harm anybody if not disturbed. But advocates,
like the GW advocates, backed by politicians, refused to listen. In a
nutshell, by removing the asbestos, more fibers were released into the
air than had you left the stuff alone, just as predicted by the
minority. Will we repeat stupidity by listening to you GW advocates?
And stop beneficial growth based on flawed data and GIGO models?
RL
Thomas Palm
@g14g2000cwa.googlegroups.com:
> What is the highest frequency of temperature changes on earth, at which
> one should sample at least twice this highest frequency, in accordance
> with the Nyquist sampling theorem, to avoid aliasing?
Wow! Had you written that in the 18th century you might have impressed
people with your insight.
Aliasing is not a problem in ground station measurements because you make
sure you measure the temperature at the same time each day. In satellites
it is more of a problem since they usually don't pass the same spot the
same time each day. This is a possible source of errors, in fact something
that plagued at least early versions of Spencer&Christy's analysis of MSU
data as they didn't properly take into account how the orbit drifted, but
by now it should be included even there.
> If there was any money in Earth Science I could have just earned a
> Nobel.
Be careful! I've just replaced my crackpot meter and I don't want you to
ruin another one.
w...@bas.ac.uk
>But I doubt that temperature is measured, by satellite or otherwise,
>every 12 hours, much less every 5 minutes.
Most weather stations report every 3 hours (or at least the major ones
do). However, they usually measure far more frequently every 10 mins
for AWSs at least. Even higher-res data would be available if you were
doing detailed process studies from particular locations (passage of
weather fronts; or more exotically T changes during eclipses). But for
general climatological pruposes its overkill.
-W.
--
William M Connolley | w...@bas.ac.uk | http://www.antarctica.ac.uk/met/wmc/
Climate Modeller, British Antarctic Survey | Disclaimer: I speak for myself
I'm a .signature virus! copy me into your .signature file & help me spread!
James Annan
> I will give this group an original idea, since you intellectual pygmies
> are so stunted it's pitiful.
>
> What is the highest frequency of temperature changes on earth, at which
> one should sample at least twice this highest frequency, in accordance
> with the Nyquist sampling theorem, to avoid aliasing?
This guy is actually getting quite funny now.
Not quite a Lubos Motl, but still...
James
Roger Coppock
temperatures are derived.
Temperatures are the average of a daily high and low. Many stations
employ a special thermometer that records these two temperatures.
(It's a U-shaped glass tube with two pistons inside it.) Sampling
times in minutes aren't an issue, these devices simply produce two
measurements a day.
Furthermore, realize that there are thousands of stations that report
daily to make the global mean temperature. The chance that all these
stations made their measurements so that their total alias resulted in
significant bias in a 125-year trendline of the global mean, the
average of tens to hundreds of millions of readings, is nil.
Finally, if you have better long term directly measured global mean
temperature data, I would invite you to present them here. The trend
in the best data available now very clearly shows global warming.
[You are also without all the facts on asbestos in school buildings,
but that is a different topic.]
raylopez99
"
This guy is actually getting quite funny now.
Not quite a Lubos Motl, but still...
James
"
James--you don't know what Nyquist theory is, do you? It's OK, most
people not involved in electrical engineering, mathematics and physics
do not.
"Aliasing is not a problem in ground station measurements because you
make sure you measure the temperature at the same time each day. In
satellites it is more of a problem since they usually don't pass the
same spot the same time each day. This is a possible source of errors,
in fact something that plagued at least early versions of
Spencer&Christy's analysis of MSU data as they didn't properly take
into account how the orbit drifted, but by now it should be included
even there.
Bill-- I believe you are confusing Nyquist sampling with statistical
sampling of a population, with replacement, to determine the mean.
They are two different problems, albeit there is a nexus. The former
is concerned with accurately reproducing the temperature profile (i.e.,
instantaneous temperature over time, not the same as mean temperature
over time), the latter is concerned with finding the "mean" temperature
over time. Two different problems are, however, related, since if your
sampling is off you will likely not find the true mean (statistically
your sample size will be too small, for the latter problem). To give
another perspective: if your sampling is too low, your tranducer is
essentially acting as a low-pass filter, and your instantaneous temp.
vs. time profile will be smoothed to give a gentle rolling curve that
might, due to aliasing, be bogus; if your sampling is too low your
sample size will be too small and according to classic Gaussian
statistics your error in the calculation of mean will be great.
"Most weather stations report every 3 hours (or at least the major ones
do). However, they usually measure far more frequently every 10 mins
for AWSs at least. Even higher-res data would be available if you were
doing detailed process studies from particular locations (passage of
weather fronts; or more exotically T changes during eclipses). But for
general climatological pruposes its overkill. -W. "
Bill--you may be right that sampling every 10 minutes is
overkill--that's why I made the disclaimer in my initial post. But if
temperature has a lot of sharp drops and spikes, then, as you can
imagine, not sampling enough will give you a distorted picture of
reality. I'm not in the field so I can't say what the 'highest
frequency' should be--whether 10 minutes is too high or two low. The
more I think about it, however, perhaps I was too harsh in saying 10
minutes should be the highest frequency for global temperature
calculations, since most of the time the temperature does not change in
10 minutes that dramatically for most places on earth. Places like on
the top of mountains are, overall, since they are so sparse compared to
the rest of the earth, thus rather trivial for the global temperature
calculations, so perhaps I was a bit too harsh in my initial post.
"Aliasing just isn't a problem. You don't know how global mean
temperatures are derived.
Temperatures are the average of a daily high and low. Many stations
employ a special thermometer that records these two temperatures.
(It's a U-shaped glass tube with two pistons inside it.) Sampling
times in minutes aren't an issue, these devices simply produce two
measurements a day.
Furthermore, realize that there are thousands of stations that report
daily to make the global mean temperature. The chance that all these
stations made their measurements so that their total alias resulted in
significant bias in a 125-year trendline of the global mean, the
average of tens to hundreds of millions of readings, is nil. "
OK Mr. Crappock. My reply to you is the same as to Dr. Bill. I can
see that intuitively your answer seems to make sense, but
mathematically I can easily see how a function which has very sharp
peaks and valleys would fail to be measured correctly by satellites
(which cover the same pattern on earth for every rotation) and ground
stations (ditto), due to aliasing (time domain) as well as failure to
sample properly a function that is widely dispersed in 3-D space
(geographically, or the space domain, not in the time domain). One
example of this, I will add parenthetically, is that famous CO2
measuring station in Hawaii that supposedly is the "best in the world
because at the altitute it exists all CO2 mixes well and there are no
sources/sinks of CO2" (you know which one if you're in the field).
Note the assumption here: that this ONE data point is representative
of the ENTIRE EARTH'S MIXED CO2 (!). Astonishing assumption.
"Finally, if you have better long term directly measured global mean
temperature data, I would invite you to present them here. The trend
in the best data available now very clearly shows global warming. "
I just did: you need to sample more frequently (Nyquist sampling
theory in the time/frequency domain) as well as more geographically
dispersed (statistical sampling with replacement, to capture the entire
earth, not just narrow satellite patterns and one station in Hawaii).
"[You are also without all the facts on asbestos in school buildings,
but that is a different topic.] "
No, I'm right on asbestos. It was driven by the lawyers and their
cohorts, not unlike GW scientists are driven by their sponsors.
You don't mind if I call you Mr. Crappock do you? C'mon, you're just
an earth scientist for Christsakes. Plus it makes you look like the
heroic martyr for a good cause, you know how much you like that and
your audience does to. What a crock.
RL
Roger Coppock
truths usually work that way.
1) No, Mana Loa is not the only source of direct measurements
of atmospheric CO2 concentrations. Mana Loa is the most
quoted source because it has been measuring the longest.
There are a couple of hundred atmospheric CO2 series.
Please see:
http://gaw.kishou.go.jp/wdcgg.html
2) No, you haven't presented any temperature data, not
even a single data point.
3) No, I am not an earth scientist.
charliew2
"raylopez99" <raylo...@yahoo.com> wrote in message
news:1112253083.6...@g14g2000cwa.googlegroups.com...
> I will give this group an original idea, since you intellectual pygmies
> are so stunted it's pitiful.
>
> What is the highest frequency of temperature changes on earth, at which
> one should sample at least twice this highest frequency, in accordance
> with the Nyquist sampling theorem, to avoid aliasing?
>
> If none of the above makes sense, I suggest you do some background
> research first.
It makes perfect sense to me, Ray. Of course, I have 15 years of background
involving process control. One other thing, I have heard this idea called
the Shannon sampling theorem, after the famous Claude E. Shannon.
By the way, I wish you luck in educating the group ... for some of the
posters here, you're definitely going to need it.
James Annan
> "raylopez99" <raylo...@yahoo.com> wrote in message
> news:1112253083.6...@g14g2000cwa.googlegroups.com...
>
>>I will give this group an original idea, since you intellectual pygmies
>>are so stunted it's pitiful.
>>
>>What is the highest frequency of temperature changes on earth, at which
>>one should sample at least twice this highest frequency, in accordance
>>with the Nyquist sampling theorem, to avoid aliasing?
>>
>>If none of the above makes sense, I suggest you do some background
>>research first.
>
>
> It makes perfect sense to me, Ray. Of course, I have 15 years of background
> involving process control. One other thing, I have heard this idea called
> the Shannon sampling theorem, after the famous Claude E. Shannon.
What a surprise that the terminally clueless charliew2 should jump at
someone else's terminally clueless nonsense, because it seems to him
like it might provide some scrap of support for his prejudices. For
someone who claims to be open-minded and seeking the truth, charliew2,
you have quite a talent for picking the wrong side in _every_ argument.
> By the way, I wish you luck in educating the group ... for some of the
> posters here, you're definitely going to need it.
You would be better served by learning from us (well, some of us at
least - my killfile saves me from most of the worst excesses on both sides).
James
Alastair McDonald
"James Annan" <still_th...@hotmail.com> wrote in message
news:424c8268$0$25197$44c9...@news3.asahi-net.or.jp...
Yes, he could start by reading "Weather Cycles - real or imaginary"
by William Burroughs which deals with aliasing and all the other
problems you get sampling data. The point is that Burroughs finds
that as soon as a cycle is identified it stops working! The answer is
that the weather and climate are not sinusoidal, they are chaotic. The
unpredictibility of the weather is not natural randomness, it is the white
noise generated by a large positive feedback!
Cheers, Alastair.
Thomas Palm
@l41g2000cwc.googlegroups.com:
> I will add parenthetically, is that famous CO2
> measuring station in Hawaii that supposedly is the "best in the world
> because at the altitute it exists all CO2 mixes well and there are no
> sources/sinks of CO2" (you know which one if you're in the field).
> Note the assumption here: that this ONE data point is representative
> of the ENTIRE EARTH'S MIXED CO2 (!). Astonishing assumption.
Yes, science can be astonishing for outsiders. Nevertheless measuring at
many points have shown that CO2 levels change so slowly that one station is
enough to follow the trend. That said, having more station as we've had for
a long time helps, since the small differences in CO2 concentration between
different places give information about where the sources and sinks are
located.
That CO2 is measured in many places not just Mauna Loa is something anyone
familiar with climate science would know, but of course that doesn't
include you.
> "Finally, if you have better long term directly measured global mean
> temperature data, I would invite you to present them here. The trend
> in the best data available now very clearly shows global warming. "
>
> I just did: you need to sample more frequently (Nyquist sampling
> theory in the time/frequency domain) as well as more geographically
> dispersed (statistical sampling with replacement, to capture the entire
> earth, not just narrow satellite patterns and one station in Hawaii).
I really recomend that you:
a) study the subject more carefully to understand what the people who
determine those trends have and haven't done.
b) Publish any findings you have on any significant errors this has caused.
You've already stated it's worth a nobel prize. Surely that goal is worth a
few weeks of real work.
raylopez99
> Yes, he could start by reading "Weather Cycles - real or imaginary"
> by William Burroughs which deals with aliasing and all the other
> problems you get sampling data. The point is that Burroughs finds
> that as soon as a cycle is identified it stops working! The answer
is
> that the weather and climate are not sinusoidal, they are chaotic.
The
> unpredictibility of the weather is not natural randomness, it is the
white
> noise generated by a large positive feedback!
>
> Cheers, Alastair.
Thanks to all. This will be my last post here for a while since I have
to read the Burroughs book (just ordered it). Looks like good stuff.
Thanks to Mr. Crappola, Dr. Bill, Alastair McDonald, James, Charlie,
and others for the feedback. Truth be told I was trying to be
provocative with my language just to flame-bait you, but you did not
rise to the occasion. My appologies if you were insulted; I was not
serious.
I started as a physics major but don't work with science except
indirectly. But I do dabble and like to read a lot. I do see some
problems that I will not be able to solve but just to state them, as I
think it's pretty obvious:
--many of the ground sampling stations seem to be near large cities,
except those that are not (Antartica), so the 'heat island' and/or
urban sprawl over the years creating a plume of industrial gases
spilling over to the ground stations might give the _illusion_ that
there is global warming and/or increased CO2. I do appreciate the
signficance of Mauna Loa however. But it is suspicious that some
stations have been identified as "sources" or "sinks" of CO2. Seems
like you can, if you want, be selective in which stations you include
in your survey, to support a thesis, with the exception of course of
the stellar Mauna Loa station established by C.D. Keeling.
--I don't know enough about the transducers used in satellites to
measure temperature and/or CO2. I know you can do amazing things with
'remote sensing' such as lasers/radar (measure the bulges in sea level
cause by gravity anomalies; discover dry riverbeds in the Sahara, etc)
but do you trust a transducer in LEO orbit that's probably the size of
a coffee can measuring data? And for CO2 is this transducer the
manometer of Dr. Charles David Keeling? A better version? Or do they
even measure CO2 in satellites? Keep in mind that as instruments
improve (as they do year over year) their sensitivity increases and
their accuracy/precision increases. I can see a scenario where an old
instrument had a combined error rate (due to say white noise and/or
sampling limits and/or a small sample size) of say +- 5%, then the
instrument got better over time (manufacturing tolerances improved;
sample sizes increased) to +-1%, and this might give the illusion of a
'upward sloping curve' when in fact its simply narrowing of the error.
Imagine one of those neat looking psuedo-sine waves generated by a
random walk generator--some of the patterns look pretty 'non-random'.
Just food for thought. The error will not "just cancel out" if the
error variance decreases--you might get a neat looking trend upwards
that looks like a dampened decaying exponential curve 1-exp(-tx), or
say like a ripple in a filter. The temperature increase alleged is
also so small: "last century the average temperature has climbed about
1 degree Fahrenheit (0.6 of a degree Celsius) around the world."
--Satellites tend to repeat their pattern--which is good so you can
compare apples to apples, but do we have enough satellites in orbit to
say the entire globe is heating up? Or just where the satellites are
looking?
--does CO2 at STP behave the same as in the 'near' vacuum of the
troposphere? Do they both 'trap or reflect heat' or otherwise act the
same in both places?
I hope people have studied these questions before jumping to
conclusions.
RL
Thomas Palm
@f14g2000cwb.googlegroups.com:
> Thanks to Mr. Crappola, Dr. Bill, Alastair McDonald, James, Charlie,
> and others for the feedback. Truth be told I was trying to be
> provocative with my language just to flame-bait you, but you did not
> rise to the occasion. My appologies if you were insulted; I was not
> serious.
It's a silly thing to do, though, if you are looking for serious answers.
> --many of the ground sampling stations seem to be near large cities,
> except those that are not (Antartica), so the 'heat island' and/or
> urban sprawl over the years creating a plume of industrial gases
> spilling over to the ground stations might give the _illusion_ that
> there is global warming and/or increased CO2.
I think the first article that tried to calculate this effect was published
by Thomas Karl 1974(?). Anyway it is a well recongnized effect that has
been studied for several decades, while the contrarians pretend this is
some new revelation only they have realized.
> I do appreciate the
> signficance of Mauna Loa however. But it is suspicious that some
> stations have been identified as "sources" or "sinks" of CO2. Seems
> like you can, if you want, be selective in which stations you include
> in your survey, to support a thesis, with the exception of course of
> the stellar Mauna Loa station established by C.D. Keeling.
It's not the stations that are sources or sinks but different regions of
the Earth. For example, most CO2 emissions occur in the northern hemosphere
so CO2 levels are slightly higher there. This is a matter of the Southern
hemisphere lagging a year or two, though, not that CO2 levels don't rise
there, the differences between different locations are minute compared to
the overall trend. Nevertheless if there is slightly more CO2 in one area
you can tell that CO2 is being emitted there.
The increasing CO2 level is such a huge effect that there is no way
whatsoever it can be an error in how it has been measured.
> --I don't know enough about the transducers used in satellites to
> measure temperature and/or CO2.
I don't think there is any global satellite measurement of CO2 yet, but I
could be wrong. It would be useful to further pin down the carbon budget.
> Keep in mind that as instruments
> improve (as they do year over year) their sensitivity increases and
> their accuracy/precision increases. I can see a scenario where an old
> instrument had a combined error rate (due to say white noise and/or
> sampling limits and/or a small sample size) of say +- 5%, then the
> instrument got better over time (manufacturing tolerances improved;
> sample sizes increased) to +-1%, and this might give the illusion of a
> 'upward sloping curve' when in fact its simply narrowing of the error.
Except by some contrarians the satellite data is the one least trusted for
reasons related to what you describe. The instruments were never designed
for long term studies, and some years ago they switched to a new, improved
instrument that makes direct comparison difficult. A lot of effort has been
spent on calibrating the data to get a useful result, but given how much
the different teams that have tried this reconstruction differ it is
unclear how much you can trust it.
Ground data is considered more reliable, and there are so many other ways
of estimating temperature: changes in the temperature in the sea, the
temperature gradient in bore holes, changes in glaciers, biological changes
such as when birds arrive at a location in spring, or how the habitat of a
butterfly moves. Even pressure data has been used as a temperature proxy.
(Being a scientist I'm sure you'll enjoy figuring out how you can measure a
temperature trend from pressure data).
> --does CO2 at STP behave the same as in the 'near' vacuum of the
> troposphere? Do they both 'trap or reflect heat' or otherwise act the
> same in both places?
As pressure drops the absorbtion lines becomes more narrow.
> I hope people have studied these questions before jumping to
> conclusions.
There are lots of people who have studied these issues and it's unlikely
that you are going to come up with anything they haven't thought about even
if you study the subject for a long time.
raylopez99
> "raylopez99" <raylo...@yahoo.com> wrote in
news:1112334575.370149.134990
> @f14g2000cwb.googlegroups.com:
>
>
> It's a silly thing to do, though, if you are looking for serious
answers.
>
> >
>
> There are lots of people who have studied these issues and it's
unlikely
> that you are going to come up with anything they haven't thought
about even
> if you study the subject for a long time.
Thanks Thomas Palm. That ground based stations are more reliable than
the un-calibrated satellites is troubling in my mind, given the 'heat
island' effect. I will look into what effect the narrowing of spectral
lines implies for CO2 properties in the upper atmosphere.
My gut feeling is that probably we do have global warming, but my gut
is not always right. Also science is prone to fads as much as anything
else, to a degree. Today's heresy is tommorrow's orthodoxy, though I
guess you can say the global warming crowd are the heretics (if you
count from 50 years ago).
Jury might still be out, though the weight of evidence based on pretty
color graphs I've seen (which seem taylored to convince a lay audience,
not the most assuring thought) seems to point to global warming.
Ray Lopez
PS--April Fool's.
Ian St. John
> Thomas Palm wrote:
>> "raylopez99" <raylo...@yahoo.com> wrote in
>> news:1112334575.370149.134990 @f14g2000cwb.googlegroups.com:
>>
>
>>
>> It's a silly thing to do, though, if you are looking for serious
>> answers.
>>
>>>
>>
>> There are lots of people who have studied these issues and it's
>> unlikely that you are going to come up with anything they haven't
>> thought about even if you study the subject for a long time.
>
> Thanks Thomas Palm. That ground based stations are more reliable than
> the un-calibrated satellites is troubling in my mind, given the 'heat
> island' effect.
Rest easy then. The data is gridded by area ( five or ten degrees ) so there
are tens of thousands of square miles in each plot. As 'duplicate' stations
are eliminated and the significance of each stations is distributed by area,
the *very* small areas of UHI effect are pretty much insignificant to the
final grid value. It has been shown that even if you do NOT correct for the
UHI effect of the urban stations, you still get a negligeable input from the
UHI effect due to the small relative area involved. However rest easy that
the UHI is compensated for and removed anyway. You can easily see that this
is so by studying the temperature anomoly. If you hypothese that the
temperature anomoly is due to UHI then you *should* see a patter of higher
anomolies where there is more 'urban'. THe fact is that the global warming
anomoly shows up at high latitudes over land as predicted. So unless you can
come up with a way to transfer the population to the high arctic, your fears
are fairly easily seen to be groundless.
http://rsd.gsfc.nasa.gov/912/urban/background.htm
http://pubs.giss.nasa.gov/abstracts/2001/HansenRuedyS.html
and for added interest
http://www.giss.nasa.gov/data/update/gistemp/maps/
compare adjusted ( for UHI, etc ) and raw data
> I will look into what effect the narrowing of
> spectral lines implies for CO2 properties in the upper atmosphere.
I believe that is the 'broadening of the band' of IR capture at low
pressure.
>
> My gut feeling is that probably we do have global warming, but my gut
> is not always right.
So take an antacid and read
http://www.grida.no/climate/ipcc_tar/wg1/index.htm
> Also science is prone to fads as much as
> anything else, to a degree. Today's heresy is tommorrow's orthodoxy,
> though I guess you can say the global warming crowd are the heretics
> (if you count from 50 years ago).
Try not to be out of date so much... this is the age of GlobalWarming and it
won't go away anytime soon.
>
> Jury might still be out,
The science brought in the verdict a long time ago. This is still being
fought in the court of public opinion, but nobody expect that jury to know
squat.
Thomas Palm
news:tnr3e.6532$x8.11...@news20.bellglobal.com:
> raylopez99 wrote:
>> Thomas Palm wrote:
>> I will look into what effect the narrowing of
>> spectral lines implies for CO2 properties in the upper atmosphere.
>
> I believe that is the 'broadening of the band' of IR capture at low
> pressure.
The bands become broader at *high* pressure as collisions with other
molecules shorten the lifetime of the excited state. It's a consequence
of the uncertainty relation dE * dt > h.
Alastair McDonald
> Thomas Palm wrote:
> > "raylopez99" <raylo...@yahoo.com> wrote in
> news:1112334575.370149.134990
> > @f14g2000cwb.googlegroups.com:
> >
>
> >
> > It's a silly thing to do, though, if you are looking for serious
> answers.
> >
> > >
> >
> > There are lots of people who have studied these issues and it's
> unlikely
> > that you are going to come up with anything they haven't thought
> about even
> > if you study the subject for a long time.
>
> Thanks Thomas Palm. That ground based stations are more reliable than
> the un-calibrated satellites is troubling in my mind, given the 'heat
> island' effect. I will look into what effect the narrowing of spectral
> lines implies for CO2 properties in the upper atmosphere.
Both sets of data are correct. It is the idea that the upper atmosphere
should warm as CO2 increases that is wrong. (BTW it is not the upper
atmosphere. It is the troposphere which is in the lower atmosphere.)
The point is that the CO2 traps the heat near the surface (in the first
30m) so the danger of global warming is from the rise in surface
temperatures, not those of the troposphere. Although it has taken me
ten years to work this out, the reception I have had here is similar to
yours.
> My gut feeling is that probably we do have global warming, but my gut
> is not always right. Also science is prone to fads as much as anything
> else, to a degree. Today's heresy is tommorrow's orthodoxy, though I
> guess you can say the global warming crowd are the heretics (if you
> count from 50 years ago).
My gut feeling is that you are right. The current fad is to believe that
rapid climate change is caused by switches in the thermohaline
circulation (THC) of the global ocean currents. Since half of the THC
flows at the base of the ocean, and more than half of the remainder
flows in the Southern Hemisphere, it is strange how this ocean
feature can have such a strong effect on the atmosphere of the
Northern Hemisphere to which the abrupt changes are mainly
confined.
> Jury might still be out, though the weight of evidence based on pretty
> color graphs I've seen (which seem taylored to convince a lay audience,
> not the most assuring thought) seems to point to global warming.
Global warming at the surface is happening and it is accelerating. But
the scientific consensus is that the models are okay. They just need
a few tweaks and they will be correct. That is despite the fact that the
possible maximum temperature rise is still three times the minimum
possible rise even after more than ten years of investigations. That is
an error band of 300%!
> PS--April Fool's.
Not sure what that is about, but if it is directed at me then my
response is that people using the grocer's apostrophe are
hardly in a position to call others fools.
Cheers, Alastair.
Thomas Palm
wrote in news:d2lqf0$msp$1...@newsg3.svr.pol.co.uk:
>
> "raylopez99" <raylo...@yahoo.com> wrote in message
> news:1112414422.6...@l41g2000cwc.googlegroups.com...
>> Thomas Palm wrote:
>> > There are lots of people who have studied these issues and it's
>> unlikely
>> > that you are going to come up with anything they haven't thought
>> about even
>> > if you study the subject for a long time.
>>
>> Thanks Thomas Palm. That ground based stations are more reliable than
>> the un-calibrated satellites is troubling in my mind, given the 'heat
>> island' effect. I will look into what effect the narrowing of spectral
>> lines implies for CO2 properties in the upper atmosphere.
>
> Both sets of data are correct. It is the idea that the upper atmosphere
> should warm as CO2 increases that is wrong. (BTW it is not the upper
> atmosphere. It is the troposphere which is in the lower atmosphere.)
> The point is that the CO2 traps the heat near the surface (in the first
> 30m) so the danger of global warming is from the rise in surface
> temperatures, not those of the troposphere. Although it has taken me
> ten years to work this out, the reception I have had here is similar to
> yours.
Just for general information: this is Alastair's own pet idea that isn't
shared by anyone else, despite having spent ten years on working on it. Not
that he has ever even tried to publish anything as far as I know.
Alastair McDonald
"Thomas Palm" <Thoma...@chello.removethis.se> wrote in message
news:Xns962C5E862443AT...@212.83.64.229...
And increasing CO2 concentration does not result in broadening since
neither the temperature or pressure change significantly.
Cheers, Alastair.
Torsten Brinch
>the
>possible maximum temperature rise is still three times the minimum
>possible rise even after more than ten years of investigations. That is
>an error band of 300%!
% of what?
Torsten Brinch
Since half of the THC
>flows at the base of the ocean, and more than half of the remainder
>flows in the Southern Hemisphere, it is strange how this ocean
>feature can have such a strong effect on the atmosphere of the
>Northern Hemisphere to which the abrupt changes are mainly
>confined.
Perhaps not so strange, take a look:
http://www.ngdc.noaa.gov/paleo/ctl/images/belt.jpg
Alastair McDonald
"Torsten Brinch" <ia...@inet.uni2.dk> wrote in message
news:bn5t41pahscl81ddu...@4ax.com...
And how much is in the Northern Hemisphere where abrupt
climate change happens. Don't forget half of that shown is
at the bottom of the sea.
Don't forget that the weather from the North Atlantic goes
eastward towards Europe, but when the THC stopped at the
start of the Youngest Dryas it was in Greenland that the largest
temperature changes were felt.
Anyway I am probably wasting my time replying to you since
someone who will not look up data for himself is hardly going
to think for himself.
Cheers, Alastair.
Torsten Brinch
>> >flows at the base of the ocean, and more than half of the remainder
>> >flows in the Southern Hemisphere, it is strange how this ocean
>> >feature can have such a strong effect on the atmosphere of the
>> >Northern Hemisphere to which the abrupt changes are mainly
>> >confined.
>>
>> Perhaps not so strange, take a look:
>> http://www.ngdc.noaa.gov/paleo/ctl/images/belt.jpg
>
>And how much is in the Northern Hemisphere where abrupt
>climate change happens. Don't forget half of that shown is
>at the bottom of the sea.
I do get your point that the deep sea part of the circulation should
not be able to interact abruptly with the atmosphere. Also the point,
that a large part of the circulation is on the Southern Hemisphere,
and likewise should not be able to interact abruptly with the Northern
Hemisphere atmosphere. Furthermore, seeing the surface part of
the Southern circulation is mainly parallel to the equator, so it
doesn't strikingly represent any heat transfer from a hotter to a
colder part of the globe).
So, what remains of the circulation, that actually does?
>Don't forget that the weather from the North Atlantic goes
>eastward towards Europe, but when the THC stopped at the
>start of the Youngest Dryas it was in Greenland that the largest
>temperature changes were felt.
Fair to say, weather systems generally take a westward course
on the relevant latitudes. However, that does not mean the air
itself moves in east to west trajectories :-) That said, I would be
interested in seeing the data you refer to.
Alastair McDonald
> On Sat, 2 Apr 2005 14:59:19 +0100, "Alastair McDonald"
> >"Torsten Brinch" <ia...@inet.uni2.dk> wrote in message
> >> On Sat, 2 Apr 2005 11:03:19 +0100, "Alastair McDonald"
> >> > Since half of the THC
> >> >flows at the base of the ocean, and more than half of the remainder
> >> >flows in the Southern Hemisphere, it is strange how this ocean
> >> >feature can have such a strong effect on the atmosphere of the
> >> >Northern Hemisphere to which the abrupt changes are mainly
> >> >confined.
> >>
> >> Perhaps not so strange, take a look:
> >> http://www.ngdc.noaa.gov/paleo/ctl/images/belt.jpg
> >
> >And how much is in the Northern Hemisphere where abrupt
> >climate change happens. Don't forget half of that shown is
> >at the bottom of the sea.
>
> I do get your point that the deep sea part of the circulation should
> not be able to interact abruptly with the atmosphere. Also the point,
> that a large part of the circulation is on the Southern Hemisphere,
> and likewise should not be able to interact abruptly with the Northern
> Hemisphere atmosphere. Furthermore, seeing the surface part of
> the Southern circulation is mainly parallel to the equator, so it
> doesn't strikingly represent any heat transfer from a hotter to a
> colder part of the globe).
>
> So, what remains of the circulation, that actually does?
The THC has two sources. Broecker appers to have omitted the second in the
diagram you referenced. Here is a truer diagram produced by Stommel;
http://www.essc.psu.edu/~bjhaupt/papers/agu01.ds/fig01-deepwater.gif
The second source of the THC is in the Weddell Sea. The North Atlantic is
just a backwater. When Lake Agassiz broke out through the Gulf of St Lawrence
it did stop the THC in the North Atlantic but only for about 200years, not the
full 1500 that the Younger Dryas lasted. See
http://www.geo.arizona.edu/dgesl/publications/abstracts/hughen_et_al&new&1998.htm
and reference to Hughen et al. in
W. S. Broecker, "What If the Conveyor Were to Shut Down? Reflections on a
Possible Outcome of the Great Global Experiment," GSA Today 9(1):1-7
(January 1999). See also http://www.geosociety.org/pubs/gsatoday/gsat9901.htm.
or
http://www.ifremer.fr/lpo/speich/DOC_OCCLIM/broeker.pdf
This two hundred year timing is similar to that obtained by the climate
models, so
they are not all wrong!
> >Don't forget that the weather from the North Atlantic goes
> >eastward towards Europe, but when the THC stopped at the
> >start of the Youngest Dryas it was in Greenland that the largest
> >temperature changes were felt.
>
> Fair to say, weather systems generally take a westward course
> on the relevant latitudes. However, that does not mean the air
> itself moves in east to west trajectories :-) That said, I would be
> interested in seeing the data you refer to.
The warming of Europe is due to the diversion of the eastery flow
southwards by the Rockies. As it travels north east across the southern
North Atlantic it warms. See Seager et al.;
http://www.atmos.washington.edu/~david/Gulf.pdf
The climate of Britain is often compared with Newfoundland, but
Seattle and Vancouver would be a fairer comparison
HTH,
Cheers, Alastair.
Raymond Arritt
>> Thanks Thomas Palm. That ground based stations are more reliable than
>> the un-calibrated satellites is troubling in my mind, given the 'heat
>> island' effect. I will look into what effect the narrowing of spectral
>> lines implies for CO2 properties in the upper atmosphere.
>
> Both sets of data are correct. It is the idea that the upper atmosphere
> should warm as CO2 increases that is wrong. (BTW it is not the upper
> atmosphere. It is the troposphere which is in the lower atmosphere.)
> The point is that the CO2 traps the heat near the surface (in the first
> 30m) so the danger of global warming is from the rise in surface
> temperatures, not those of the troposphere.
This simply cannot be right given the physical nature of the problem.
First and most importantly, CO2 does not "trap heat." CO2 absorbs
infrared radiation. CO2 also emits infrared radiation. Understandably,
people often tie the absorption and emission together: they have the
idea that CO2 absorbs a certain amount of heat energy in the form of
infrared radiation, and then re-emits that same amount of heat energy in
the form of infrared radiation.
But that isn't how it works. It's better to think of the absorption and
emission as being separate. Then, you can realize that the energy CO2
emits as infrared radiation isn't restricted to the radiation that it
absorbs. The emitted energy can come from any number of sources: latent
heat of condensation in thunderstorms, heat transported from the surface
by turbulent eddies, and so on. The energy that CO2 radiates will
depend on the temperature of the CO2 -- regardless of how the
temperature reached its value.
The second point is that CO2 is well-mixed through the entire depth of
the troposphere (and beyond), so it doesn't act only or even mainly near
the surface.
Put these two facts together and you can see the statement that "CO2
traps heat near the surface" has to be wrong in at least two fundamental
ways.
There are a number of other complications but this idea that CO2 "traps
heat" is one of the greatest obstructions to understanding the global
warming issue.
Alastair McDonald
"Raymond Arritt" <raymon...@hotmail.com> wrote in message
news:uBz3e.7484$kT5.5174@attbi_s21...
> Alastair McDonald wrote:
> > The point is that the CO2 traps the heat near the surface (in the first
> > 30m) so the danger of global warming is from the rise in surface
> > temperatures, not those of the troposphere.
>
> This simply cannot be right given the physical nature of the problem.
>
> First and most importantly, CO2 does not "trap heat." CO2 absorbs
> infrared radiation. CO2 also emits infrared radiation. Understandably,
> people often tie the absorption and emission together: they have the
> idea that CO2 absorbs a certain amount of heat energy in the form of
> infrared radiation, and then re-emits that same amount of heat energy in
> the form of infrared radiation.
That is only half right. It will do that if the air is in thermodynamic
equilibrium (TE). I argue that the most of the troposphere is in TE,
and so the amount of CO2 does not matter since whatever is
absorbed is reemitted.
> But that isn't how it works. It's better to think of the absorption and
> emission as being separate. Then, you can realize that the energy CO2
> emits as infrared radiation isn't restricted to the radiation that it
> absorbs. The emitted energy can come from any number of sources: latent
> heat of condensation in thunderstorms, heat transported from the surface
> by turbulent eddies, and so on. The energy that CO2 radiates will
> depend on the temperature of the CO2 -- regardless of how the
> temperature reached its value.
In all of the troposphere the amount of radiation emitted by the CO2
molecules is determined by their temperature, but the amount absorbed
for CO2 near the surface is determined by the radiation from the
Earth's surface.
> The second point is that CO2 is well-mixed through the entire depth of
> the troposphere (and beyond), so it doesn't act only or even mainly near
> the surface.
True. But you said that the amount of radiation emitted is controlled by
its temperature, and increasing CO2 concentration does not increase
its temperature because the effect on the density of the air is insignificant.
Therefore increasing CO2 concentration will not increase the temperature
of the troposphere.
In this new model, the lowest layer of the troposphere is in local
thermodynamic equilibrium (LTE) where it is emitting at the local
temperature. At the top of the atmosphere (which stretches down
to the top of the troposphere) the air is in LTE too. But the radiation
emitted there escapes to space. Here the radiation is greater than
the temperature of the gas because it is at Effective Temperature.
> Put these two facts together and you can see the statement that "CO2
> traps heat near the surface" has to be wrong in at least two fundamental
> ways.
>
> There are a number of other complications but this idea that CO2 "traps
> heat" is one of the greatest obstructions to understanding the global
> warming issue.
No, you have missed an important point. CO2 near the surface absorbs
radiation emitted by the surface, and re-emits 50% of it back in the
direction of the surface. In effect it is trapping half of the radiation. Of
the radiation re-emitted upwards half of that is re-emitted downwards
(trapped). Soon it is all trapped!
The mistake being made by the conventional model is to ignore the
fact that 50% of the absorbed outgoing longwave radiation (OLR) is
re-emitted as incoming radiation.
HTH,
Cheers, Alastair.
Ian St. John
So the less time the molecule can stay in an excited state, the more easily
it can become excited. Hmm. I must have fallen asleep during the quantum
physics class. I do remember vaguely something about how you can borrow
infinite energy as long as you pay it back fast enough. One of those
problems in deriving real world values from the quantum theories.
I am a bit confused then. It was an early statement ( proven wrong, IIRC by
the 'broadening of the bands' that the IR capture of the lower atmophere was
already saturated, so) that increased CO2 could have no significant effect.
The main effect of global warming occurs at the tropopause ( acutally near
there ) where radiation physics takes over from
convection/radiation/conduction that occurs in the troposphere. The
'broadening of the bands' occurs only at high pressure, then how can it
effect the planetary balance that is predominantly occuring at low pressure.
How long it takes for a photon to work it's way up to the tropopause to be
emitted would only affect lag, not temperate since the level of CO2 would
not be a factor, while increasing the concentration at the tropopause does
decrease the chance of an emission and so moves the 'equipotential point' of
emissions upward.
Can you enlighten me?
Thomas Palm
> Thomas Palm wrote:
>> The bands become broader at *high* pressure as collisions with other
>> molecules shorten the lifetime of the excited state. It's a
>> consequence of the uncertainty relation dE * dt > h.
>
> So the less time the molecule can stay in an excited state, the more
> easily it can become excited.
The absorbtion band becomes wider, but the peak also gets lower so the
total absorbtion crossection remains constant. But since a photon at the
center of an absorbtion peak is going to be absorbed very quickly in the
atmosphere that lower peak has little influence, while the fact that
photons can get absorbed further from the center is important.
> Hmm. I must have fallen asleep during
> the quantum physics class. I do remember vaguely something about how
> you can borrow infinite energy as long as you pay it back fast enough.
> One of those problems in deriving real world values from the quantum
> theories.
You don't even need quantum mechanics to see this effect. You have the same
effect in music. If you play a short note it's hard to hear the exact
pitch, and the longer the note the better you can determine the pitch. IT's
somthing you can easily understand if you play along with taking the
Fourier transform of a truncated sine wave.
> I am a bit confused then. It was an early statement ( proven wrong,
> IIRC by the 'broadening of the bands' that the IR capture of the lower
> atmophere was already saturated, so) that increased CO2 could have no
> significant effect.
Yes, early physicists measured the absorbtion of CO2 at low pressure and
didn't realized it changed in the real atmosphere. (Except for Arrhenius
who was so early that there were no such measurements so he had to rely on
primitive measurements through the Earth's atmosphere, so he got it right
more or less by accident)
> The main effect of global warming occurs at the tropopause ( acutally
> near there ) where radiation physics takes over from
> convection/radiation/conduction that occurs in the troposphere. The
> 'broadening of the bands' occurs only at high pressure, then how can
> it effect the planetary balance that is predominantly occuring at low
> pressure.
Now you are getting above the level where I can explain stuff. I know
quantum optics on a professional basis, and I can qualitatively say a bit
about the greenhouse effect, but I can't really say which effects are most
important in the real atmosphere. For example, I can't without doing a lot
of work tell you how much of the pressure broadening remains at the
tropopause.
w...@bas.ac.uk
>Thanks Thomas Palm. That ground based stations are more reliable than
>the un-calibrated satellites is troubling in my mind, given the 'heat
>island' effect. I will look into what effect the narrowing of spectral
>lines implies for CO2 properties in the upper atmosphere.
For UHI, this is a good place to start:
http://en.wikipedia.org/wiki/Urban_heat_island
>My gut feeling is that probably we do have global warming, but my gut
>is not always right.
You should ignore your gut feeling and look at the science. www.ipcc.ch
is the obvious starting point.
-W.
--
William M Connolley | w...@bas.ac.uk | http://www.antarctica.ac.uk/met/wmc/
Climate Modeller, British Antarctic Survey | Disclaimer: I speak for myself
I'm a .signature virus! copy me into your .signature file & help me spread!
David Ball
wrote:
>
>But I doubt that temperature is measured, by satellite or otherwise,
>every 12 hours, much less every 5 minutes.
>
I guess the minute-by-minute data I get in our office from the
5 main observing sites in our region is a figment of my imagination.
Joshua Halpern
> Thomas Palm wrote:
>
>>"Ian St. John" <ist...@noemail.usa> wrote in
>>
>>>
>>>>Thomas Palm wrote:
>>
>>>> I will look into what effect the narrowing of
>>>>spectral lines implies for CO2 properties in the upper atmosphere.
>>>
>>>I believe that is the 'broadening of the band' of IR capture at low
>>>pressure.
>>
>>The bands become broader at *high* pressure as collisions with other
>>molecules shorten the lifetime of the excited state. It's a
>>consequence of the uncertainty relation dE * dt > h.
>
> So the less time the molecule can stay in an excited state, the more easily
> it can become excited. Hmm. I must have fallen asleep during the quantum
> physics class. I do remember vaguely something about how you can borrow
> infinite energy as long as you pay it back fast enough. One of those
> problems in deriving real world values from the quantum theories.
>
In general there are two causes for line broadening, Doppler and
collisional or pressure broadening.
Doppler broadening results from molecular motion. The component of the
velocity in the direction of the emitted or absorbed light is shifted by
v/c where v is the speed. The distribution of molecular velocities
is determined by temperature. The distribution of velocities is wider
(ie there are more high velocity molecules) at hotter temperature. In
the troposphere temperature decreases with altitude, so CO2 Doppler
decreases with altitude. Since the std deviation of the velocity
distribution sigma(v) ~ sqrt(RT/m) you can get an idea of how much by
looking at the average temperature at any level. Those who want more
detail probably have books where they can find it.
Pressure broadening results from the interaction of the
absorbing/emitting molecule with other nearby molecules of the same
(generally a stronger effect) or different types. Since pressure
decreases with altitude the higher you go, the narrower the lines.
The details are very long winded, mostly because typically the presssure
broadening effects are measured/calculated for individual molecular
pairs (eg CO2 N2).
Beyond this there are collisional effects which come into play where
excited, or not excited molecules are scattered into other
vibrational-rotational states by collisions. This is the primary
determinant of how long a particular vibrationally excited molecule
stays excited. Under tropospheric conditions the de-excitation time is
much shorter than the average time that an isolated, vibrationally
excited molecule would take to radiate. When a CO2 molecule absorbs an
IR photon, it almost always degrades the energy to heat by collision.
(You can read greenhouse gas where I write CO2, including water vapor)
However, the heat energy also excites ground state CO2 molecules to the
excited state by collision. The average time for this process at
tropospheric temperatures and pressures is faster than the radiative
lifetime. The net effect is that radiation and collision are decoupled,
and the problem can be treated by first measuring the net absorption at
a particular layer, then calculating how much energy this puts into the
layer, (I am neglecting convection and latent heat but GCMs do not).
Input and output of the layer need to be balanced, so the temperature
can be calculated by figuring out the temperature that a layer has to
reach for balance, given thermal excitation of the CO2 and the radiative
line strength.
> I am a bit confused then. It was an early statement ( proven wrong, IIRC by
> the 'broadening of the bands' that the IR capture of the lower atmophere was
> already saturated, so) that increased CO2 could have no significant effect.
>
See above. Also think of the atmosphere as a tilted board with nails
half driven into it. If you drop a marble on the board, the average
time it takes for the marble to make its way to the bottom depends on
the density of the nails.
> The main effect of global warming occurs at the tropopause ( acutally near
> there ) where radiation physics takes over from
> convection/radiation/conduction that occurs in the troposphere.
No. Essentially the level at which the atmosphere radiates to space is
well below the tropopause
The
> 'broadening of the bands' occurs only at high pressure, then how can it
> effect the planetary balance that is predominantly occuring at low pressure.
> How long it takes for a photon to work it's way up to the tropopause to be
> emitted would only affect lag, not temperate since the level of CO2 would
> not be a factor, while increasing the concentration at the tropopause does
> decrease the chance of an emission and so moves the 'equipotential point' of
> emissions upward.
>
> Can you enlighten me?
>
>
Hope this helped
josh halpern
Raymond Arritt
> "Raymond Arritt" <raymon...@hotmail.com> wrote in message
> news:uBz3e.7484$kT5.5174@attbi_s21...
>> Alastair McDonald wrote:
> That is only half right. It will do that if the air is in thermodynamic
> equilibrium (TE). I argue that the most of the troposphere is in TE,
> and so the amount of CO2 does not matter since whatever is
> absorbed is reemitted.
Again, you're falling into the "absorption and re-emission" fallacy.
>> But that isn't how it works. It's better to think of the absorption and
>> emission as being separate. Then, you can realize that the energy CO2
>> emits as infrared radiation isn't restricted to the radiation that it
>> absorbs. The emitted energy can come from any number of sources: latent
>> heat of condensation in thunderstorms, heat transported from the surface
>> by turbulent eddies, and so on. The energy that CO2 radiates will
>> depend on the temperature of the CO2 -- regardless of how the
>> temperature reached its value.
>
> In all of the troposphere the amount of radiation emitted by the CO2
> molecules is determined by their temperature, but the amount absorbed
> for CO2 near the surface is determined by the radiation from the
> Earth's surface.
The same physical principles apply to the entire atmosphere. Are you
proposing that all of the upward long-wave flux in the relevant
wavelength ranges is entirely absorbed by a very thin path length of CO2
near the earth's surface? If so, I'd be curious to see the computations
you've done to support this.
> In this new model, the lowest layer of the troposphere is in local
> thermodynamic equilibrium (LTE) where it is emitting at the local
> temperature. At the top of the atmosphere (which stretches down
> to the top of the troposphere) the air is in LTE too. But the radiation
> emitted there escapes to space. Here the radiation is greater than
> the temperature of the gas because it is at Effective Temperature.
I find this difficult to follow, since there's no such thing as the "top
of the atmosphere." Presumably you're referring to some layer at a
great height; where might this layer be located? Also, it's not clear
what you mean by "effective temperature"; do you mean something like the
equivalent blackbody temperature?
>> There are a number of other complications but this idea that CO2 "traps
>> heat" is one of the greatest obstructions to understanding the global
>> warming issue.
>
> No, you have missed an important point. CO2 near the surface absorbs
> radiation emitted by the surface, and re-emits 50% of it back in the
> direction of the surface. In effect it is trapping half of the radiation.
> Of the radiation re-emitted upwards half of that is re-emitted downwards
> (trapped). Soon it is all trapped!
>
> The mistake being made by the conventional model is to ignore the
> fact that 50% of the absorbed outgoing longwave radiation (OLR) is
> re-emitted as incoming radiation.
This is untrue; more correctly, you've re-discovered the algorithm that
longwave radiation parameterizations in climate models have used for
many years. All modern-day longwave radiation parameterizations assume
that radiation emitted by a given layer goes both upward and downward.
That is, they already include the fact that upward flux of radiation
from one layer is partly absorbed and re-emitted by the layer above
(which absorbs and re-emits to the layers above and below that one, and
so on). This is one of the reasons why the radiation parameterization
is one of the most computationally-demanding parts of a climate model:
every layer interacts with every other layer through both upward and
downward fluxes. Some of the old longwave parameterizations for
short-term NWP used a cooling-to-space approximation but I don't even
the NWP models do that any more.
Ian St. John
> Ian St. John wrote:
>> Thomas Palm wrote:
>>
>>> "Ian St. John" <ist...@noemail.usa> wrote in
>>>
>>>> raylopez99 wrote:
>>>>
>>>>> Thomas Palm wrote:
>>>
>>>>> I will look into what effect the narrowing of
>>>>> spectral lines implies for CO2 properties in the upper atmosphere.
>>>>
>>>> I believe that is the 'broadening of the band' of IR capture at low
>>>> pressure.
>>>
>>> The bands become broader at *high* pressure as collisions with other
>>> molecules shorten the lifetime of the excited state. It's a
>>> consequence of the uncertainty relation dE * dt > h.
>>
>> So the less time the molecule can stay in an excited state, the more
>> easily it can become excited. Hmm. I must have fallen asleep during
>> the quantum physics class. I do remember vaguely something about how
>> you can borrow infinite energy as long as you pay it back fast
>> enough. One of those problems in deriving real world values from the
>> quantum theories.
>>
> There are several things tangled together here.
I realise that my 'picture' is flawed but I have to espouse it in order for
the flaws to be seen and commented on.
>
> In general there are two causes for line broadening, Doppler and
> collisional or pressure broadening.
>
> Doppler broadening results from molecular motion. The component of
> the velocity in the direction of the emitted or absorbed light is
> shifted by v/c where v is the speed. The distribution of
> molecular velocities
> is determined by temperature. The distribution of velocities is wider
> (ie there are more high velocity molecules) at hotter temperature. In
> the troposphere temperature decreases with altitude, so CO2 Doppler
> decreases with altitude. Since the std deviation of the velocity
> distribution sigma(v) ~ sqrt(RT/m) you can get an idea of how much by
> looking at the average temperature at any level. Those who want more
> detail probably have books where they can find it.
O.K. I gather that you mean troposphere temperature decreases with
*increasing* altitude? At least, that is the way the standard atmosphere
works. You may have assumed that this was obvious.
>
> Pressure broadening results from the interaction of the
> absorbing/emitting molecule with other nearby molecules of the same
> (generally a stronger effect) or different types. Since pressure
> decreases with altitude the higher you go, the narrower the lines.
>
> The details are very long winded, mostly because typically the
> presssure broadening effects are measured/calculated for individual
> molecular pairs (eg CO2 N2).
O.K. I don't get the original error then, since it was about the idea that
the troposphere was saturated in terms of the capture of IR by CO2 and thus
adding more could not affect things. As well, I inferred the 'pressure
broadening' to be a low pressure phenomenon due to statements such as
:Tropospheric ozone, especially in the cold upper troposphere (6- to 10-km
altitude), is an effective greenhouse gas largely because of pressure
broadening of its 9.6-?m absorption band. :
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=34040
Of course, they may have had it wrong or I may have understood the comment
improperly. I have a lot of faith in your knowledge of these matters, even
more than Thomas Palms.
>
> Beyond this there are collisional effects which come into play where
> excited, or not excited molecules are scattered into other
> vibrational-rotational states by collisions. This is the primary
> determinant of how long a particular vibrationally excited molecule
> stays excited. Under tropospheric conditions the de-excitation time
> is much shorter than the average time that an isolated, vibrationally
> excited molecule would take to radiate. When a CO2 molecule absorbs
> an IR photon, it almost always degrades the energy to heat by
> collision.
The problem of what happens to heat in the troposphere is somewhat
problematical since convection can 'take over' and beside, any block to IR
energy would only result in a delay in the heat escaping, not a change in
the amount of heat escaping which is determined by the amount of heat
influx. The balance must be met at some point thought there can be dynamic
lags.
>
> (You can read greenhouse gas where I write CO2, including water vapor)
>
> However, the heat energy also excites ground state CO2 molecules to
> the excited state by collision. The average time for this process at
> tropospheric temperatures and pressures is faster than the radiative
> lifetime. The net effect is that radiation and collision are
> decoupled, and the problem can be treated by first measuring the net
> absorption at a particular layer, then calculating how much energy
> this puts into the layer, (I am neglecting convection and latent heat
> but GCMs do not). Input and output of the layer need to be balanced,
> so the temperature can be calculated by figuring out the temperature
> that a layer has to reach for balance, given thermal excitation of
> the CO2 and the radiative line strength.
Or, one can take the 'equipotential point' and calculate the distance
multiplied by the lapse rate for us simpler fellows... ;-)
>
>> I am a bit confused then. It was an early statement ( proven wrong,
>> IIRC by the 'broadening of the bands' that the IR capture of the
>> lower atmophere was already saturated, so) that increased CO2 could
>> have no significant effect.
>>
> See above. Also think of the atmosphere as a tilted board with nails
> half driven into it. If you drop a marble on the board, the average
> time it takes for the marble to make its way to the bottom depends on
> the density of the nails.
As I would understand it, IR capture is irrelevenat in terms of the total
flow through the system no matter how much longer it takes for each
individual ball to get from the top to the bottom. Only where there is a
reasonable chance for the IR energy to escape does the chance of capture
play a role in the thermal balance, and this moves upwards as more CO2 is
injected.
>
>> The main effect of global warming occurs at the tropopause (
>> acutally near there ) where radiation physics takes over from
>> convection/radiation/conduction that occurs in the troposphere.
>
> No. Essentially the level at which the atmosphere radiates to space
> is well below the tropopause
The 'equipotential point' at which fifty percent of IR photons can escape
capture is supposed to be near there, though no exactly there. Of course, if
you taken the quarter emission level to the eighths emission level, etc, the
'point' of emission may give the appearance of being lower.
>
> The
>> 'broadening of the bands' occurs only at high pressure, then how can
>> it effect the planetary balance that is predominantly occuring at
>> low pressure. How long it takes for a photon to work it's way up to
>> the tropopause to be emitted would only affect lag, not temperate
>> since the level of CO2 would not be a factor, while increasing the
>> concentration at the tropopause does decrease the chance of an
>> emission and so moves the 'equipotential point' of emissions upward.
>>
>> Can you enlighten me?
>>
>>
> Hope this helped
Somewhat, though as you can see, I am not entirely clear on the matter yet.
>
> josh halpern
Ian St. John
My apologies, but I think that Joshuas explanations were clearer.
>
>> I am a bit confused then. It was an early statement ( proven wrong,
>> IIRC by the 'broadening of the bands' that the IR capture of the
>> lower atmophere was already saturated, so) that increased CO2 could
>> have no significant effect.
>
> Yes, early physicists measured the absorbtion of CO2 at low pressure
> and didn't realized it changed in the real atmosphere. (Except for
> Arrhenius who was so early that there were no such measurements so he
> had to rely on primitive measurements through the Earth's atmosphere,
> so he got it right more or less by accident)
The way I remember it ( and maybe I had it wrong ) was that they did the CO2
emission expereiments at atmspheric pressure and it was this that led them
to believe that the CO2 lines were already saturated. Why would they try to
pull a vacuum? This was prior to 1950 or so. I believe Anderson wrote on
lorentz or pressure broadening sometime in the fifties.
>
>> The main effect of global warming occurs at the tropopause ( acutally
>> near there ) where radiation physics takes over from
>> convection/radiation/conduction that occurs in the troposphere. The
>> 'broadening of the bands' occurs only at high pressure, then how can
>> it effect the planetary balance that is predominantly occuring at low
>> pressure.
>
> Now you are getting above the level where I can explain stuff. I know
> quantum optics on a professional basis, and I can qualitatively say a
> bit about the greenhouse effect, but I can't really say which effects
> are most important in the real atmosphere. For example, I can't
> without doing a lot of work tell you how much of the pressure
> broadening remains at the tropopause.
I have switched over to Joshua Halpern for a more detailed discussion. Feel
free to comment.
Thomas Palm
> Thomas Palm wrote:
>> "Ian St. John" <ist...@noemail.usa> wrote in
>>> I am a bit confused then. It was an early statement ( proven wrong,
>>> IIRC by the 'broadening of the bands' that the IR capture of the
>>> lower atmophere was already saturated, so) that increased CO2 could
>>> have no significant effect.
>>
>> Yes, early physicists measured the absorbtion of CO2 at low pressure
>> and didn't realized it changed in the real atmosphere. (Except for
>> Arrhenius who was so early that there were no such measurements so he
>> had to rely on primitive measurements through the Earth's atmosphere,
>> so he got it right more or less by accident)
>
> The way I remember it ( and maybe I had it wrong ) was that they did
> the CO2 emission expereiments at atmspheric pressure and it was this
> that led them to believe that the CO2 lines were already saturated.
> Why would they try to pull a vacuum? This was prior to 1950 or so. I
> believe Anderson wrote on lorentz or pressure broadening sometime in
> the fifties.
Check http://www.aip.org/history/climate/co2.htm
The reason that they used vacuum is that these measurements weren't done
for the purpose of explaining the greenhouse effect, they were basic
science, and physicists like to keep things simple when possible so they
studied one gas at a time in isolation and derived an absorbtion profile.
Then many people tried to apply these results to the atmosphere without
considering whether or not they were relevant there.
Alastair McDonald
"Ian St. John" <ist...@noemail.usa> wrote in message
news:SPH3e.7063$x8.12...@news20.bellglobal.com...
> As I would understand it, IR capture is irrelevenat in terms of the total
> flow through the system no matter how much longer it takes for each
> individual ball to get from the top to the bottom. Only where there is a
> reasonable chance for the IR energy to escape does the chance of capture
> play a role in the thermal balance, and this moves upwards as more CO2 is
> injected.
What I am saying is that the greenhouse IR balls never gets to the top
because half of it is being batted back down to the surface at every
level.
This is probably not much help to you, but it does help me explain my
argument nicely.
Thank you again Ian :-)
Cheers, Alastair.
Joshua Halpern
> "Ian St. John" <ist...@noemail.usa> wrote in message
> news:SPH3e.7063$x8.12...@news20.bellglobal.com...
>
>
>>As I would understand it, IR capture is irrelevenat in terms of the total
>>flow through the system no matter how much longer it takes for each
>>individual ball to get from the top to the bottom. Only where there is a
>>reasonable chance for the IR energy to escape does the chance of capture
>>play a role in the thermal balance, and this moves upwards as more CO2 is
>>injected.
>
>
> What I am saying is that the greenhouse IR balls never gets to the top
> because half of it is being batted back down to the surface at every
> level.
>
josh halpern
Ian St. John
> "Ian St. John" <ist...@noemail.usa> wrote in
> news:vgI3e.7076$x8.12...@news20.bellglobal.com:
>
>> Thomas Palm wrote:
>>> "Ian St. John" <ist...@noemail.usa> wrote in
>>>> I am a bit confused then. It was an early statement ( proven wrong,
>>>> IIRC by the 'broadening of the bands' that the IR capture of the
>>>> lower atmophere was already saturated, so) that increased CO2 could
>>>> have no significant effect.
>>>
>>> Yes, early physicists measured the absorbtion of CO2 at low pressure
>>> and didn't realized it changed in the real atmosphere. (Except for
>>> Arrhenius who was so early that there were no such measurements so
>>> he had to rely on primitive measurements through the Earth's
>>> atmosphere, so he got it right more or less by accident)
>>
>> The way I remember it ( and maybe I had it wrong ) was that they did
>> the CO2 emission expereiments at atmspheric pressure and it was this
>> that led them to believe that the CO2 lines were already saturated.
>> Why would they try to pull a vacuum? This was prior to 1950 or so. I
>> believe Anderson wrote on lorentz or pressure broadening sometime in
>> the fifties.
>
> Check http://www.aip.org/history/climate/co2.htm
O.K. Good page by the way, thanks. I'll add it to my library.
> The reason that they used vacuum is that these measurements weren't
> done for the purpose of explaining the greenhouse effect, they were
> basic science, and physicists like to keep things simple when
> possible so they studied one gas at a time in isolation and derived
> an absorbtion profile.
Your reference says..
"The early studies sending radiation through gases in a tube had an
unsuspected logical flaw - they were measuring bands of the spectrum at
sea-level pressure and temperature." ( jsut as I remembered it ).
"At low pressure each band resolved into a cluster of sharply defined lines,
like a picket fence, with gaps between the lines where radiation would get
through.(24) "
Thus, the 'broadening of the bands' ( overlapping each other at high
pressure) was what caused early researchers to conclude that the IR capture
was 'saturated' and it was only later, when the low pressure studies were
exhumed and physics caught up that the 'windows' for emisson caused by the
narrower and more sharply defined bands at low pressure ( where the planet
actually emits from) gave a way for CO2 to effect a change in the thermal
balance.
Ian St. John
> Alastair McDonald wrote:
>> "Ian St. John" <ist...@noemail.usa> wrote in message
>> news:SPH3e.7063$x8.12...@news20.bellglobal.com...
>>
>>
>>> As I would understand it, IR capture is irrelevenat in terms of the
>>> total flow through the system no matter how much longer it takes
>>> for each individual ball to get from the top to the bottom. Only
>>> where there is a reasonable chance for the IR energy to escape does
>>> the chance of capture play a role in the thermal balance, and this
>>> moves upwards as more CO2 is injected.
>>
>>
>> What I am saying is that the greenhouse IR balls never gets to the
>> top because half of it is being batted back down to the surface at
>> every level.
>>
> Read up on Zenos paradox and mirrors
>
> josh halpern
Or simply commment that if greenhouse gase were such a 'perfect insulator'
that no heat escaped, the temperature at the surface would be infinite.
>
>> This is probably not much help to you, but it does help me explain my
>> argument nicely.
Actaully, it doesn't help at all. It is a distraction from a more reasoned
argument. Thanks to Thomas Palm, I now have a better handle on the subject.
It is the narrowing of the bands at altitude ( the inverse of pressure
broadening ) that 'opens up windows' through which heat can still be emitted
and thus allows changes in CO2 levels to affect the thermal balance.
Early experiments at atmospheric pressure had 'broadening of the bands' to
effectively close all IR spectra windows and thus seem to prove that the
bands were saturated. However, emission at high altitdue ( and low
pressure ) were overlooked by this first approach.
>>
>> Thank you again Ian :-)
Please don't thank me. Your post is entirely your own.
>>
>> Cheers, Alastair.
Thomas Palm
> Thomas Palm wrote:
>> "Ian St. John" <ist...@noemail.usa> wrote in
>> Check http://www.aip.org/history/climate/co2.htm
>
> O.K. Good page by the way, thanks. I'll add it to my library.
It seems it was too long since I actually read that page and I had
forgotten much of the contents. A good lesson why you should include
references if you want to convey the truth, and should avoid it if you
don't want to look like a fool occasionally.
Ian St. John
> "Ian St. John" <ist...@noemail.usa> wrote in
> news:GUU3e.169$6k4....@news20.bellglobal.com:
>
>> Thomas Palm wrote:
>>> "Ian St. John" <ist...@noemail.usa> wrote in
>
>>> Check http://www.aip.org/history/climate/co2.htm
>>
>> O.K. Good page by the way, thanks. I'll add it to my library.
>
> It seems it was too long since I actually read that page and I had
> forgotten much of the contents. A good lesson why you should include
> references if you want to convey the truth, and should avoid it if you
> don't want to look like a fool occasionally.
"Peer review' is a continuous process.. ;-)
Thanks for the sounding board. I actually learned something in this thread
which puts it far ahead of almost all others. Thanks also to Joshua
Halpern..
Vendicar Decarian
> What is the highest frequency of temperature changes on earth, at which
> one should sample at least twice this highest frequency, in accordance
> with the Nyquist sampling theorem, to avoid aliasing?
Well, I've seen it drop 40'C in a hour. But of course the smaller you go
the more rapid the temperature fluctuations. Changes on the order of
several million degrees can occur in nanoseconds with just a couple of
atoms.
Such is the nature of the definition of temperature.
Alastair McDonald
"Ian St. John" <ist...@noemail.usa> wrote in message
> Joshua Halpern wrote:
> > Alastair McDonald wrote:
> >> "Ian St. John" <ist...@noemail.usa> wrote in message
> >> news:SPH3e.7063$x8.12...@news20.bellglobal.com...
> >>
> >>
> >>> total flow through the system no matter how much longer it takes
> >>> for each individual ball to get from the top to the bottom. Only
> >>> where there is a reasonable chance for the IR energy to escape does
> >>> the chance of capture play a role in the thermal balance, and this
> >>> moves upwards as more CO2 is injected.
> >>
> >>
> >> What I am saying is that the greenhouse IR balls never gets to the
> >> top because half of it is being batted back down to the surface at
> >> every level.
> >>
> > Read up on Zenos paradox and mirrors
> >
> > josh halpern
>
> Or simply commment that if greenhouse gase were such a 'perfect insulator'
> that no heat escaped, the temperature at the surface would be infinite.
The greenhouse gases only block certain bands of radiation. There is
a 'window"..
> It is the narrowing of the bands at altitude ( the inverse of pressure
> broadening ) that 'opens up windows' through which heat can still be emitted
> and thus allows changes in CO2 levels to affect the thermal balance.
Huh?
The OLR is emitted by the surface. If it is entirely trapped in the lower
troposphere then the narrowing of the bands at higher altitudes is not
going to allow more to radiation to escape since it has already all
been trapped lower down. BTW it is not the bands which narrow. It is
the lines. When the lines broaden they form bands.
> Early experiments at atmospheric pressure had 'broadening of the bands' to
> effectively close all IR spectra windows and thus seem to prove that the
> bands were saturated. However, emission at high altitude ( and low
> pressure ) were overlooked by this first approach.
As I already punted out, It is the lines which broaden into bands, but the
bands do not block all OLR. They only block all the radiation at the
wavelength of the bands, not that at the wavelength of the "window" which
can itself be thought of as a band.
My thesis is that the first approach was correct, but increasing CO2
does cause surface temperature to rise. The mistake of the first
approach was to assume that the situation would stabilise, but it
does not because of the diurnal cycle. The air in the boundary
layer is continually warming and cooling. If you add CO2 to the
atmosphere, this cycle is more efficient and the surface warms. So
the GH bands are saturated, but increasing CO2 raises surface
temperature.
> >> Thank you again Ian :-)
>
> Please don't thank me. Your post is entirely your own.
Yes, but your mistakes are so helpful :-)
Cheers, Alastair.
Alastair McDonald
"Joshua Halpern" <vze2...@verizon.net> wrote in message
news:EdU3e.20801$k66.10695@trnddc03...
> Alastair McDonald wrote:
> > "Ian St. John" <ist...@noemail.usa> wrote in message
> > news:SPH3e.7063$x8.12...@news20.bellglobal.com...
> >
> >
> >>As I would understand it, IR capture is irrelevenat in terms of the total
> >>flow through the system no matter how much longer it takes for each
> >>individual ball to get from the top to the bottom. Only where there is a
> >>reasonable chance for the IR energy to escape does the chance of capture
> >>play a role in the thermal balance, and this moves upwards as more CO2 is
> >>injected.
> >
> >
> > What I am saying is that the greenhouse IR balls never gets to the top
> > because half of it is being batted back down to the surface at every
> > level.
> >
> Read up on Zenos paradox and mirrors
Balls!
That's what Ian and I were discussing. Not Hares and tortoises. It is
about time you put that book of fables down and started reading
an algebra book where it describes how to the sum a geometrical
series.
Anyway, what about answering Ian's post? Or are you just picking
on mine, because you have no answer for Ian?
Cheers, Alastair.
Alastair McDonald
> Alastair McDonald wrote:
> > "Raymond Arritt" <raymon...@hotmail.com> wrote in message
> > news:uBz3e.7484$kT5.5174@attbi_s21...
> >> Alastair McDonald wrote:
>
> > That is only half right. It will do that if the air is in thermodynamic
> > equilibrium (TE). I argue that the most of the troposphere is in TE,
> > and so the amount of CO2 does not matter since whatever is
> > absorbed is reemitted.
>
> Again, you're falling into the "absorption and re-emission" fallacy.
No, it is you who is assuming that the whole of the troposphere behaves
in only one manner. That works if you accept a straight line lapse rate for
the troposphere. See Figure 1 in Held IM, Soden BJ (2000) Water vapor
feedback and global warming. Annu Rev Energy Environ., 25, 441-475.
http://www.gfdl.noaa.gov/reference/bibliography/2000/annrev00.pdf
(H&S) But the real lapse rate is not a straight line. It is a series of
zigzags, with the the lapse rate in the boundary layer flip-flopping
between a positive and negative gradient.
I am arguing that the H&S model is wrong. In the simplest version
of my Z-model, the lapse rate is only straight above the boundary
layer. In that section the air is heated by the release of latent heat,
and warmed as the result of adiabatic expansion where the air is
rising. This regulates the temperature of the CO2 molecules and
hence the rate at which they emits radiation. Since they are
surrounded by other CO2 molecules radiating at the same intensity,
the amount they absorb is equal to the amount they emit. They
are in TE, despite your "absorption and re-emission" fallacy.
In the boundary layer the situation is different, where there are two
regimes, the first during the day and the second during the night. During
the day when the surface is cooler than the air, the radiation absorbed
by CO2 will be greater than that emitted. This is because the molecules
of CO2 will be de-excited by collisions with O2 and N2 molecules
before they can re-emit their energy. This leads to a warming of the
air until it reaches the temperature of the surface when again TE will
prevail. Since the surface temperature is changing continuously, TE
will only be instantaneously reached soon after the surface temperature
begins to fall. During daytime, the air WILL absorb heat from the OLR.
As the surface temperature falls during the night, the CO2 will radiate
at the temperature of air. The radiation emitted will exceed that
absorbed from the surface by the CO2 and due to collisions the air will
cool. Note that there is no "absorption and re-emission (equality?)"
fallacy here.
> > In all of the troposphere the amount of radiation emitted by the CO2
> > molecules is determined by their temperature, but the amount absorbed
> > for CO2 near the surface is determined by the radiation from the
> > Earth's surface.
>
> The same physical principles apply to the entire atmosphere. Are you
> proposing that all of the upward long-wave flux in the relevant
> wavelength ranges is entirely absorbed by a very thin path length of CO2
> near the earth's surface?
Yes - 30 meters thick.
> If so, I'd be curious to see the computations
> you've done to support this.
The following is a quote from an MSc dissertation at UEA
http://clima.ictr.pd.cnr.it/microclima/sturaro/MODEL.htm
"A simplified description of the atmosphere was applied as suggested by
McIlveen (1992) considering only the main greenhouse gases (GHG), i.e. carbon
dioxide (CO2) and water vapour. The atmosphere is divided in layers containing
enough CO2 to saturate the absorption at its characteristic wavelengths. Such
a quantity of CO2 is contained in a column of some 30 m at ground level at
standard atmospheric pressure of 1013.25 mb and temperature of 288.15 K. "
"McIlveen, R. 1992: Fundamentals of weather and climate, Chapman & Hall,
London."
For a detailed calculation see;
Messerole, C.A., Mulcahy, F.M., Lutz, J., and Yousif, H.A. (1997) "CO2
Absorption of IR Radiated by the Earth" Journal of Chemical Education, 74 p.
316-7
> > In this new model, the lowest layer of the troposphere is in local
> > thermodynamic equilibrium (LTE) where it is emitting at the local
> > temperature. At the top of the atmosphere (which stretches down
> > to the top of the troposphere) the air is in LTE too. But the radiation
> > emitted there escapes to space. Here the radiation is greater than
> > the temperature of the gas because it is at Effective Temperature.
>
> I find this difficult to follow, since there's no such thing as the "top
> of the atmosphere." Presumably you're referring to some layer at a
> great height; where might this layer be located? Also, it's not clear
> what you mean by "effective temperature"; do you mean something like the
> equivalent blackbody temperature?
Yes, effective emission temperature as defined in Held & Soden Fig. 1.
Let me try again. The above made sense to me when I wrote it but ...
In the Z-model the troposphere is divided into three zones. In the
lowest zone the air is in LTE, where the radiation emitted is set by
the temperature of the air/CO2, but the radiation emitted is not equal
to the radiation absorbed.
In the middle zone, the emitted radiation and
the absorbed radiation are equal and are set by the temperature of the
air. The air temperature is set as you described by latent heat etc.
NB there is no heating of the boundary layer by latent heat because
that is below the condensation level.)
In the highest zone of the
troposphere (and stretching up to the base of the thermosphere), the
emitted radiation from the CO2 molecules is set by their temperature,
but the radiation emerging from that zone is greater than that emitted
by the CO2 because the CO2 is too rare to trap the radiation being
emitted at lower altitudes. Here the atmosphere is in a different type
of type of LTE from the lowest layer.
> > The mistake being made by the conventional model is to ignore the
> > fact that 50% of the absorbed outgoing longwave radiation (OLR) is
> > re-emitted as incoming radiation.
>
> This is untrue; more correctly, you've re-discovered the algorithm that
> longwave radiation parameterizations in climate models have used for
> many years. All modern-day longwave radiation parameterizations assume
> that radiation emitted by a given layer goes both upward and downward.
> That is, they already include the fact that upward flux of radiation
> from one layer is partly absorbed and re-emitted by the layer above
> (which absorbs and re-emits to the layers above and below that one, and
> so on). This is one of the reasons why the radiation parameterization
> is one of the most computationally-demanding parts of a climate model:
> every layer interacts with every other layer through both upward and
> downward fluxes. Some of the old longwave parameterizations for
> short-term NWP used a cooling-to-space approximation but I don't even
> the NWP models do that any more.
OK, I'll accept that my knowledge of the most recent models is can
always be criticised because I am not working with them. It did seem
unlikely to me that the models were wrong by a factor of 2. But only
50% of the radiation (heat) absorbed by the air containing CO2 is
re-emitted upwards. The greenhouse effect of CO2 acting on OLR
is soon dissipated vertically. This explains why the MSU's are not
registering an increase in temperature in the troposphere.
The current models have the surface OLR forcing it way out through a
thick atmosphere to space. In the Z-model, the boundary layer acts as
an engine pumping latent heat high into the troposphere, where it
radiates to space through a thin atmosphere. As the CO2 increases,
the boundary layer operates at a higher temperature, increasing the
surface temperatures, and the water vapour in the troposphere, which
produces more clouds and rain.
Cheers, Alastair.
Eric Swanson
[cut]
>OK, I'll accept that my knowledge of the most recent models is can
>always be criticised because I am not working with them. It did seem
>unlikely to me that the models were wrong by a factor of 2. But only
>50% of the radiation (heat) absorbed by the air containing CO2 is
>re-emitted upwards. The greenhouse effect of CO2 acting on OLR
>is soon dissipated vertically. This explains why the MSU's are not
>registering an increase in temperature in the troposphere.
But Alastair, the MSU/AMSU data DOES show a warming trend.
Even that from Christy and Spencer. The other 4 groups came in with
even greater warming, close to that found in the surface data. Doesn't
that make you think that Christy and Spencer's work is suspect?
--
Eric Swanson --- E-mail address: e_swanson(at)skybest.com :-)
--------------------------------------------------------------
Ian St. John
> "Ian St. John" <ist...@noemail.usa> wrote in message
> news:I1V3e.175$6k4....@news20.bellglobal.com...
>> Joshua Halpern wrote:
>>> Alastair McDonald wrote:
>>>> "Ian St. John" <ist...@noemail.usa> wrote in message
>>>> news:SPH3e.7063$x8.12...@news20.bellglobal.com...
>>>>
>>>>
>>>>> As I would understand it, IR capture is irrelevant in terms of the
>>>>> total flow through the system no matter how much longer it takes
>>>>> for each individual ball to get from the top to the bottom. Only
>>>>> where there is a reasonable chance for the IR energy to escape
>>>>> does the chance of capture play a role in the thermal balance,
>>>>> and this moves upwards as more CO2 is injected.
>>>>
>>>>
>>>> What I am saying is that the greenhouse IR balls never gets to the
>>>> top because half of it is being batted back down to the surface at
>>>> every level.
>>>>
>>> Read up on Zenos paradox and mirrors
>>>
>>> josh halpern
>>
>> Or simply commment that if greenhouse gase were such a 'perfect
>> insulator' that no heat escaped, the temperature at the surface
>> would be infinite.
>
> The greenhouse gases only block certain bands of radiation. There is
> a 'window"..
No. That was the issue with 'pressure broadening'. That it 'smeared' all of
the windows closed which is why there was no change to IR when they doubled
CO2 levels in the lab ( under normal pressure ). The multiple windows only
show clearly at lower pressure.
http://www.aip.org/history/climate/co2.htm#N_7_
>
>> It is the narrowing of the bands at altitude ( the inverse of
>> pressure broadening ) that 'opens up windows' through which heat can
>> still be emitted and thus allows changes in CO2 levels to affect the
>> thermal balance.
>
> Huh?
It is simple if you understand that the surface cannot radiate directly to
space due to greenhouse gases and thus the 'radiation surface' is at
altitude ( and lower pressure ) where the narrowing of the bands opens up a
much greater chance for an IR photon to be emitted to space permanently.
>
> The OLR is emitted by the surface. If it is entirely trapped in the
> lower troposphere then the narrowing of the bands at higher altitudes
> is not going to allow more to radiation to escape since it has
> already all
> been trapped lower down. BTW it is not the bands which narrow. It is
> the lines. When the lines broaden they form bands.
The thermal energy has to 'work its way' up before being emitted,but it is
emitted from the upper atmopshere. The lower levels are too saturated to
emit significantly to space.
>
>> Early experiments at atmospheric pressure had 'broadening of the
>> bands' to effectively close all IR spectra windows and thus seem to
>> prove that the bands were saturated. However, emission at high
>> altitude ( and low
>> pressure ) were overlooked by this first approach.
>
> As I already punted out, It is the lines which broaden into bands,
> but the bands do not block all OLR. They only block all the radiation
> at the wavelength of the bands, not that at the wavelength of the
> "window" which can itself be thought of as a band.
Essentially, they did block ( as in delay, as in like an insulation) all
radiation AT THE SURFACE. Change in CO2 concentration, if confied to the
surface, would have no effect on the planetary balance. Much of the thermal
energy gets carried up by convection as well as the radiation between
layers.
>
> My thesis is
crap.
raylopez99
Thanks VD. This would argue that remote sensing or that sensing at
ground stations twice a day (to get a min and a max, then dividing by
two to get an average) is subject to harmful aliasing. If aliasing is
a problem, digital signal theory predicts your "true mean" temperature
will be different (possibly lower) than your 'recorded' mean
temperature. And if we are talking about a few degrees over 100 years
this measurement error difference could explain 'global warming'.
RL
raylopez99
knowledgeable and respectible scientists are in disagreement over the
exact mechanism for global warming, including but not limited to what
the oceans absorb, what the upper atmosphere will do to C02 (whether
the spectral line change will block or emit or otherwise alter the heat
equation), and other such factors including possibly aliasing and
calibration of different remote sensing devices, and possibly even heat
island effects at measuring stations.
This is not meant to say that there is no global warming--just that it
is not as 'ironclad' as E = mc^2 (which is actually a Taylor Series
where the higher order c^3 terms drop out I understand).
If scientists cannot agree, what chance does the layman have, unless
you 'dumb down' some text and make it into a hagiography (i.e.,
propanganda)?
I have other questions about GW, that I might raise in another thread,
besides the aliasing problem and the C02 in a rarified atmosphere
problem in this thread.
I will leave you with this thought: a professor in physics once told
me that to model heat transfer in a certain process no fewer than three
papers were presented at a conference. The first paper predicted that
radiation was the primary mode of heat tranfer in the process; the
second paper predicted that convection was the primary mode; the third
that conduction was the primary mode. The most amazing thing was that
ALL THREE PAPERS AGREED WITH (and predicted) THE DATA.
Think about that.
In short, can it be that we do have global warming (subject to possible
aliasing and measurement error, so perhaps we don't really), but that
CO2 is not the primary cause? Or even man-made CO2?
Fuel for thought.
That said, what is the purpose of science, if not to polemicize a cause
(irony intended)? The Spanish Inquisition proved this with Galileo's
retraction. Call it "useful science" or "the ends justify the means".
That is, as Lady Thatcher once said, having industrial gases pour out
into the atmosphere is essentially an experiment that supposes man-made
gases do not cause global warming--can we afford to do this experiment,
in particular if the assumption is wrong? We cannot, so politicizing
Global Warming, making it seem the science is "air-tight" and not
subject to debate, is a useful ploy to making society realize they must
stop polluting. Harsh, not unlike the Spanish practice of strangling a
newly converted Inca to save his soul by preventing his 'back-sliding'
and falling back into heathenism, but, if you believe that your
Christian religion is the only true and correct one, and that Heaven
and Hell exist, then a 'useful' practice, from that point of view.
RL
Thomas Palm
@z14g2000cwz.googlegroups.com:
> Thanks VD. This would argue that remote sensing or that sensing at
> ground stations twice a day (to get a min and a max, then dividing by
> two to get an average) is subject to harmful aliasing. If aliasing is
> a problem, digital signal theory predicts your "true mean" temperature
> will be different (possibly lower) than your 'recorded' mean
> temperature. And if we are talking about a few degrees over 100 years
> this measurement error difference could explain 'global warming'.
Could you give any physical reason for why you would get any such aliasing
effect of a size large enough to matter?
Thomas Palm
@g14g2000cwa.googlegroups.com:
> It is clear from going through this thread that reputable,
> knowledgeable and respectible scientists are in disagreement over the
> exact mechanism for global warming, including but not limited to what
> the oceans absorb, what the upper atmosphere will do to C02 (whether
> the spectral line change will block or emit or otherwise alter the heat
> equation), and other such factors including possibly aliasing and
> calibration of different remote sensing devices, and possibly even heat
> island effects at measuring stations.
In this group you have a very diverse group of people, most with no formal
training in climate science, so of course you get different answers,
usually more or less wrong. That only reflects the nature of an open
discussion group. If you really want to learn the science, get a good text
book in the subject.
> This is not meant to say that there is no global warming--just that it
> is not as 'ironclad' as E = mc^2 (which is actually a Taylor Series
> where the higher order c^3 terms drop out I understand).
I'd disagree with the Taylor series part, you can derive it exactly. If you
try asking in a group like this you will get diverging answers on such an
issue too. Not to mention what you will get to questions such as "How
important is E=mc^2 for the development of a nuclear bomb?" or "Does the
equation apply to an exploding stick of dynamite as well?". This doesn't
mean that experts in the field can't give you a correct answer, only that
most people here aren't experts.
> In short, can it be that we do have global warming (subject to possible
> aliasing and measurement error, so perhaps we don't really), but that
> CO2 is not the primary cause? Or even man-made CO2?
People have thought about it and come up with no better explanation.
Actually there are two problems that would need to be solved in that case.
first you'd have to come up with some other mechanism that can explain why
the globe is warming, and then you'd need to come up with an explanation
for why the extra CO2 isn't causing as much warming as predicted. Possible,
I guess, but not exactly likely.
raylopez99
> "raylopez99" <raylo...@yahoo.com> wrote in
news:1112680722.974439.317040
> @g14g2000cwa.googlegroups.com:
>
> > It is clear from going through this thread that reputable,
> > knowledgeable and respectible scientists are in disagreement over
the
> > exact mechanism for global warming, including but not limited to
what
> > the oceans absorb, what the upper atmosphere will do to C02
(whether
> > the spectral line change will block or emit or otherwise alter the
heat
> > equation), and other such factors including possibly aliasing and
> > calibration of different remote sensing devices, and possibly even
heat
> > island effects at measuring stations.
>
> In this group you have a very diverse group of people, most with no
formal
> training in climate science, so of course you get different answers,
> usually more or less wrong. That only reflects the nature of an open
> discussion group. If you really want to learn the science, get a good
text
> book in the subject.
Why would a textbook give you anything but a textbook answer? If I get
a text book on how the law works, how Congress passes laws, and how a
sausage is made, I will only learn about the stylized, first order
approximation of how things work, not the smelly, messy details. The
devil is in the details. I don't want a base from which to build on
(the textbook), I want to know what assumptions are built into the GW
computer standard model.
>
> > This is not meant to say that there is no global warming--just that
it
> > is not as 'ironclad' as E = mc^2 (which is actually a Taylor Series
> > where the higher order c^3 terms drop out I understand).
>
> I'd disagree with the Taylor series part, you can derive it exactly.
Yes, perhaps an exact solution is possible to Einstein's equation, but
I remember the Taylor series deriviation, and you can find it here as
well: http://www.geocentricity.com/ba1/no76/emc2.html (note
interesting comment how E=mc^2 is found in Heaviside's expansion and in
Maxwell's works)
> If you
> try asking in a group like this you will get diverging answers on
such an
> issue too. Not to mention what you will get to questions such as "How
> important is E=mc^2 for the development of a nuclear bomb?" or "Does
the
> equation apply to an exploding stick of dynamite as well?". This
doesn't
> mean that experts in the field can't give you a correct answer, only
that
> most people here aren't experts.
And how do you know who the expert is here? Perhaps the one that uses
the least scatology? Or that posts last? Seems like you are an expert
in physics but do you know how the GW standard model for climate works?
What the initial conditions are (very important in a non-linear
equation, as you may know)?
>
> > In short, can it be that we do have global warming (subject to
possible
> > aliasing and measurement error, so perhaps we don't really), but
that
> > CO2 is not the primary cause? Or even man-made CO2?
>
> People have thought about it and come up with no better explanation.
> Actually there are two problems that would need to be solved in that
case.
> first you'd have to come up with some other mechanism that can
explain why
> the globe is warming, and then you'd need to come up with an
explanation
> for why the extra CO2 isn't causing as much warming as predicted.
Possible,
> I guess, but not exactly likely.
Anything is possible, I have found, if you throw enough money at it.
The canonical model on GW could be received wisdom only because so much
money has been invested in the model that alternate theories have been
neglected. Not unlike the standard model in astrophysics and particle
physics that sometimes gets revised and is continuously being tweaked.
There is no harm in this because economic growth does not depend on
getting the model right. And even a 'bad' model can predict
something--but basing world growth on a 'bad' model is disasterous if
the model is wrong.
The bottom line is this: do you trust a computer simulation to predict
a complex (chaotic, non-linear, feedback driven) system like the
earth's atmosphere, when scientists have problems predicting exact
motion in the so-called "three body" problem of physics? I'm not
making fun of physics, just saying that any model has assumptions and
holes, that can be challenged. Nothing is absolute. Something about
Carl Popper comes to mind, but I'm too tired to Google it.
In short do you want to base world growth on a computer simulation done
on IBM's Blue Gene supercomputer? Not a reassuring thought, especially
after the Mars space craft that crashed because of a programmer's error
a few years ago.
RL
Alastair McDonald
"Ian St. John" <ist...@noemail.usa> wrote in message
> crap.
Cheers, Alastair.
Alastair McDonald
"Eric Swanson" <swa...@notspam.net> wrote in message
news:d2slce$1622$1...@news3.infoave.net...
> In article <d2rsd9$u69$3...@newsg4.svr.pol.co.uk>,
alas...@abmcdonald.leavethisout.freeserve.co.uk says...
>
> [cut]
>
> >OK, I'll accept that my knowledge of the most recent models is can
> >always be criticised because I am not working with them. It did seem
> >unlikely to me that the models were wrong by a factor of 2. But only
> >50% of the radiation (heat) absorbed by the air containing CO2 is
> >re-emitted upwards. The greenhouse effect of CO2 acting on OLR
> >is soon dissipated vertically. This explains why the MSU's are not
> >registering an increase in temperature in the troposphere.
>
> But Alastair, the MSU/AMSU data DOES show a warming trend.
> Even that from Christy and Spencer. The other 4 groups came in with
> even greater warming, close to that found in the surface data. Doesn't
> that make you think that Christy and Spencer's work is suspect?
If it was so suspect, all the other scientists would be denouncing it. That
has not happened. It is only the editors of Science and Nature who
are whipping up this anti-C&S hysteria, goaded on by the sceptics.
For instance, a reply to Fu et al. was not even printed in Nature. It was
put on the web where access was restricted to subscribers only. So
much for open access! Here is the abstract.
Nature (02 December 2004); doi:10.1038/nature03208
Atmospheric science: Tropospheric temperature series from satellites
SIMON TETT AND PETER THORNE
Arising from: Q. Fu et al. Nature 429, 55-58 (2004); see also communication
from Gillett et al.; Fu et al. reply
There has been considerable debate about changes in the temperature of the
troposphere measured using the Microwave Sounding Unit (MSU) instrument or
radiosondes. Fu et al. linearly combine time series from two MSU channels to
estimate vertically integrated 850-300-hPa temperatures and claim consistency
between surface and free-troposphere warming for one MSU record. We believe
that their approach overfits the data, produces trends that overestimate
warming and gives overly optimistic uncertainty estimates. There still remain
large differences between observed tropospheric temperature trends and those
simulated by a climate model.
http://www.nature.com/cgi-taf/DynaPage.taf?file=/nature/journal/v432/n7017/abs/nature03208_fs.html
You have thoroughly investigated C&S's work to the extent that you found a
minor error. Are you now saying that your investigations were inadequate and
C&S is all wrong? I am not arguing that C&S is perfect. Only that if the
Z-model is better than that of Held & Soden, then that would explain Tett and
Thorne's concerns.
I don't know if you have read any history of science books such as Bill
Bryson's "A short history of nearly everything" or "The Discovery of Global
Warming " by Weart but they are littered with the scientists making mistakes.
See for instance Thomas' recommendation
http://www.aip.org/history/climate/co2.htm There is a tendency to think that
this generation is different and we have it all correct. That is being as
egocentric as believing that this generation is the one which will end the
world. Eh? Well ..er.
Cheers, Alastair.
correct it would explain while there is dispute about the MSU
James Annan
> And how do you know who the expert is here?
Anyone who can't tell, isn't one. Anyone who rants about "commies",
"eco-terrorists" or "homos" when their errors are corrected, certainly
isn't one either. There are, however, several posters whose expertise
can easily be verified in a few minutes of googling.
HTH, HAND.
James
Thomas Palm
@f14g2000cwb.googlegroups.com:
> Thomas Palm wrote:
>> "raylopez99" <raylo...@yahoo.com> wrote in
>> In this group you have a very diverse group of people, most with no
> formal
>> training in climate science, so of course you get different answers,
>> usually more or less wrong. That only reflects the nature of an open
>> discussion group. If you really want to learn the science, get a good
> text
>> book in the subject.
>
> Why would a textbook give you anything but a textbook answer? If I get
> a text book on how the law works, how Congress passes laws, and how a
> sausage is made, I will only learn about the stylized, first order
> approximation of how things work, not the smelly, messy details. The
> devil is in the details. I don't want a base from which to build on
> (the textbook), I want to know what assumptions are built into the GW
> computer standard model.
You can't understand the messy details until you've learned the basics.
You want a royal road, but there isn't one to climate science any more
than to geometry. A good textbook on climate modelling will give you many
of the messy details and the knowledge needed to read the primary
research articles giving you the rest of them.
>> > This is not meant to say that there is no global warming--just that
> it
>> > is not as 'ironclad' as E = mc^2 (which is actually a Taylor Series
>> > where the higher order c^3 terms drop out I understand).
>>
>> I'd disagree with the Taylor series part, you can derive it exactly.
>
> Yes, perhaps an exact solution is possible to Einstein's equation, but
> I remember the Taylor series deriviation, and you can find it here as
> well: http://www.geocentricity.com/ba1/no76/emc2.html (note
> interesting comment how E=mc^2 is found in Heaviside's expansion and in
> Maxwell's works)
> And how do you know who the expert is here? Perhaps the one that uses
> the least scatology? Or that posts last?
Some, like William Connolley make it simple by including their
credentials in their signature, others you will simply have to read what
they write for a while or do a google. If you can't tell who is reliable
you definitely shouldn't get your facts from a group like this but stick
to the textbooks.
> Seems like you are an expert
> in physics but do you know how the GW standard model for climate works?
Only a very simple outline. I realize how much work it would be to
understand them in a meaningful way, and even more to understand enough
to start finding real weaknesses in them.
> Anything is possible, I have found, if you throw enough money at it.
> The canonical model on GW could be received wisdom only because so much
> money has been invested in the model that alternate theories have been
> neglected.
What alternative models? You can't research anything unless you have any
idea what it might be!
> Not unlike the standard model in astrophysics and particle
> physics that sometimes gets revised and is continuously being tweaked.
> There is no harm in this because economic growth does not depend on
> getting the model right. And even a 'bad' model can predict
> something--but basing world growth on a 'bad' model is disasterous if
> the model is wrong.
Basing world growth on the assumption that the best available science is
wrong is a lot more likely to be disastrous, though. There simply isn't
any 100% certainty in any decisions made, yet decisions have to be made.
You may pretend that continuing to emit more and more CO2 is "doing
nothing" but that too will have disastrous consequences if science is
right.
> The bottom line is this: do you trust a computer simulation to predict
> a complex (chaotic, non-linear, feedback driven) system like the
> earth's atmosphere, when scientists have problems predicting exact
> motion in the so-called "three body" problem of physics?
People may have problem with the three body problem, but do you trust
thermodynamics? There you have billions and billions of particles, yet
people can make models that work to good accuracy. They do this by
calculating the averages, and this is what climate science does too. The
chaos is found in the weather, but on longer timescales climate is a lot
more stable.
> I'm not
> making fun of physics, just saying that any model has assumptions and
> holes, that can be challenged. Nothing is absolute. Something about
> Carl Popper comes to mind, but I'm too tired to Google it.
Do you fly? Are you sure there isn't some flaw in aerodynamics that will
make your plane crash? Like it or not, your life depends on science being
a workable process to gain knowledge. You can't just use these general
attack on the scientific method when it comes to climate science and
still trust it everywhere else.
> In short do you want to base world growth on a computer simulation done
> on IBM's Blue Gene supercomputer? Not a reassuring thought, especially
> after the Mars space craft that crashed because of a programmer's error
> a few years ago.
Do you want to base your life on the assumption that that supercomputer
simulation is wrong? That simpler models run on personal computers are
wrong? That even the most simple models that you can do by pen and paper
are wrong? The fact is that you get global warming in everything from
simple 1D models to the most complex 3D GCM:s.
Thomas Palm
@f14g2000cwb.googlegroups.com:
> Thomas Palm wrote:
>> > This is not meant to say that there is no global warming--just that
> it
>> > is not as 'ironclad' as E = mc^2 (which is actually a Taylor Series
>> > where the higher order c^3 terms drop out I understand).
>>
>> I'd disagree with the Taylor series part, you can derive it exactly.
>
> Yes, perhaps an exact solution is possible to Einstein's equation, but
> I remember the Taylor series deriviation, and you can find it here as
> well: http://www.geocentricity.com/ba1/no76/emc2.html (note
> interesting comment how E=mc^2 is found in Heaviside's expansion and in
> Maxwell's works)
This is pretty typical of "web page science" (Or should I say crackpot
science? Some parts of that page clearly qualifies). You can do a
handwaving derivation like that, but it is not how it is done in a proper
textbook, where stuff like the Lorentz factor isn't just assumed. There you
instead start by formally deriving the relativistic expression for kinetic
energy and note that using a Taylor expression you can show that for low
velocities this is reduced to the ordinary E=mv^2/2, i.e. you got it wrong,
it's the classic expression that is an approximation.
Raymond Arritt
> Why would a textbook give you anything but a textbook answer? If I get
> a text book on how the law works, how Congress passes laws, and how a
> sausage is made, I will only learn about the stylized, first order
> approximation of how things work, not the smelly, messy details. The
> devil is in the details. I don't want a base from which to build on
> (the textbook), I want to know what assumptions are built into the GW
> computer standard model.
All the models are published in the open literature -- all you have to
do is look. Many (most?) also have source code freely available.
The main point is that there's no "standard model." All the models are
built of a number of coupled components. Each atmospheric model has a
dynamical core which solves the basic hydrodynamic equations. There are
several very different possible formulations for the dynamical core, for
example finite differences versus spectral methods. (Some models have a
choice of dynamical core.) Coupled to the dycore are parameterizations
for numerous physical processes: short- and long-wave radiative
transfer; deep convective clouds; "stable" (grid-scale) clouds;
turbulent exchange; and so on. There are different formulations for all
of these parameterizations. Each atmospheric model is then coupled to
an ocean model, a sea-ice model and so on, each of which has a number of
formulations available.
So, to repeat, there's no "standard model": there are different
dynamical cores which are in turn coupled to different physical
parameterizations and different models for other parts of the earth
system. One of the strongest pieces of evidence supporting the idea of
CO2-induced global warming is that all these different models predict
warming to occur over the rest of this century. They vary somewhat in
magnitude and (especially) regional details of the projected climate,
but ALL predict warming.
raylopez99
Hey Tom--your credibility is in question, or perhaps I did not
reference the Taylor series derivation of Einsteins equation E=mc2
properly. Perhaps I confused you since the Taylor series expansion is
usually called a binomial series expansion (see reference below), which
(from memory, I could be wrong) is a special case of a Taylor series
expansion.
Below is another reference, repeated in full.
This makes me wonder--who is the expert here? I haven't done this
derivation since over 20 years ago (how times does fly!) but I still
remember it.
And now I'm supposed to believe you 'experts' in a much more complex
question called Global Warming? :-)
RL
http://www.madsci.org/posts/archives/apr2000/956844514.Ph.r.html
Re: How do I calculate the energy-mass relationship?
Date: Wed Apr 26 18:04:14 2000
Posted By: Sidney Chivers, , Nuclear Engineering, retired
Area of science: Physics
ID: 956282795.Ph Message:
In 1905, Albert Einstein published a paper entitled ?Does the Inertia
of a
Body Depend Upon Its Energy Content?, which included a derivation of
the
formula ?energy is equal to mass times the speed of light squared?.
That
derivation does not depend upon calculus. I Found the article in
Einstein: The Principle of Relativity; H. A. Lorentz, H. Weyl, and H.
Minkowski; Dover Publications, Inc.; a 1952 unabridged and unaltered
reprint of a 1923 translation of the original.
Essential Elements of Einstein?s Mathematical Basis for E = mc2
I. Let there be two inertial reference frames as follows:
A. Frame 1: with coordinates (x,y,z)
B. Frame 2: with coordinates (x?, y?, z?); where the x?,
y?, and z?
axes are parallel to the x, y, and z axes of Frame 1 respectively.
Also,
Frame 2 has a velocity with a magnitude of v and directed in the
positive-x direction.
II. Let there a be a body of mass m at rest in Frame 1 and let its
energy
relative to Frame 1 be E0. Let the energy of the same body relative to
Frame 2 be H0.
III. Let this same body emit light of energy 1/2 L measured relative
to
Frame 1, in a direction making an angle phi with the x-axis.
Simultaneously, let light of equal energy (1/2 L) be emitted in the
opposite direction. After light emission, let the energy of the body
be
E1 in Frame 1 and H1 in Frame 2.
IV. To simplify the remainder of the derivation, I set phi equal to
zero,
in effect having the light emitted in the positive-x and negative-x
directions.
V. By the principle of conservation of energy, in Frame 1,
E0 = E1 + 1/2 L + 1/2 L [equation 1]
or the energy of the body at rest in Frame 1 before light emission is
equal to the energy of the body after emission plus the energy of the
light emitted.
VI. By the principle of relativity, energy is also conserved in Frame
2,
or
H0 = H1 + 1/2 L [ (1 - v/c) / (1 - v2/c2)**(1/2) ] + 1/2 L [ (1 + v/c)
/
(1 - v2/c2)**(1/2) ] [equation 2]
Now, this is the first part of the derivation that may not be standard
fare in high school physics. The equation is further complicated
because
I did not use a fancy equation writer, thus the following shorthand is
used in the equation:
v2 - stands for velocity squared
c2 - stands for the speed of light squared
(1 - v2/c2)**(1/2) - is used to indicated the square root of (1 -
v2/c2)
If you need additional information to understand where equation 2 comes
from, you may need to study Lorentz transformation as described in
introductory textbooks on special relativity, such as the following:
Ray Skinner, Relativity for Scientists and Engineers, Dover
Publications,
1982
Edwin F. Taylor and John Archibald Wheeler, Spacetime Physics, W. H.
Freeman and Company, 1966
Some high school and most college physics texts also cover special
relativity to the level of detail needed to understand equation 2.
VII. Einstein then equated the two differences of the form H - E as
follows
H0 - E0 = K0 + C [equation 3]
H1 - E1 = K1 + C [equation 4]
where C is an additive constant not changed by the emission of light
from
the body described above, and K0 and K1 represent kinetic energy of the
body in Frame 1 and Frame 2, respectively.
In more detail, first combine equations 1 and 2,
( H0 - E0 ) = ( H1 - E1 ) + 1/2 L{ [(1-v/c)/(1-v2/c2)**(1/2)] -
1
} + 1/2 L { [(1+v/c)/(1-v2/c2)**(1/2)] - 1 }
simplify to,
(K0 + C) = (K1 + C) + L [ 1/(1-v2/c2)**(1/2)]
and then,
K0 - K1 = L [ 1/(1-v2/c2)**(1/2)] [equation 5]
VIII. Finally, by a binomial series expansion,
[ 1/(1-v2/c2)**(1/2)] becomes 1/2 v2/c2, or equation 5 becomes
change in kinetic energy of the body is equal to 1/2 [L/c2] v2, or
since kinetic energy is generally known as 1/2 m v2, it follows, given
that m0 is the mass of the body before light emission and m1 is the
mass
of the body after light emission, that equation 5, now in the form
K0 - K1 = 1/2 [L/c2] v2 = 1/2 [m0 - m1] v2 [equation
6],
or
the change in mass of the body, from before to after light emission,
must
be equal to L/c2, or
L = [m0 - m1] c2 [ equation 7],
essentially identical to
Energy is equal to mass times the speed of light squared.
My apologies for such a lengthy reply. I hope this helps. I thought
mention of intertial reference frames might also cause difficulty, but
a
careful explanation of inertial refererence frames could easily have
doubled the length of this response. The same references, though, have
in
depth discussions of inertial reference frames, without the use of
calculus.
raylopez99
they probably copy the same formulaes used?
Eric Swanson
>
>
>"Eric Swanson" <swa...@notspam.net> wrote in message
>news:d2slce$1622$1...@news3.infoave.net...
>> In article <d2rsd9$u69$3...@newsg4.svr.pol.co.uk>,
>alas...@abmcdonald.leavethisout.freeserve.co.uk says...
>>
>> [cut]
>>
>> >OK, I'll accept that my knowledge of the most recent models is can
>> >always be criticised because I am not working with them. It did seem
>> >unlikely to me that the models were wrong by a factor of 2. But only
>> >50% of the radiation (heat) absorbed by the air containing CO2 is
>> >re-emitted upwards. The greenhouse effect of CO2 acting on OLR
>> >is soon dissipated vertically. This explains why the MSU's are not
>> >registering an increase in temperature in the troposphere.
>>
>> But Alastair, the MSU/AMSU data DOES show a warming trend.
>> Even that from Christy and Spencer. The other 4 groups came in with
>> even greater warming, close to that found in the surface data. Doesn't
>> that make you think that Christy and Spencer's work is suspect?
>
>If it was so suspect, all the other scientists would be denouncing it. That
>has not happened. It is only the editors of Science and Nature who
>are whipping up this anti-C&S hysteria, goaded on by the sceptics.
No. Why do you think there were several papers written which showed errors in
the original Spencer & Christy work, such as the drift in LEQ time, the orbit
decay problem and the mirror correction factor issue? And, there was the NAS
report, which ended by pointing to Prabhakara's then unpublished work as a
check on S & C's results, which, BTW, showed a greater warming than S & C? Why
do you think more than 50 people attended the RVTT workshop at NOAA's NCDC in
October 2003? The report from that meeting isn't due out for a couple of
months.
>For instance, a reply to Fu et al. was not even printed in Nature. It was
>put on the web where access was restricted to subscribers only. So
>much for open access! Here is the abstract.
>
>Nature (02 December 2004); doi:10.1038/nature03208
>Atmospheric science: Tropospheric temperature series from satellites
>SIMON TETT AND PETER THORNE
>
>Arising from: Q. Fu et al. Nature 429, 55-58 (2004); see also communication
>from Gillett et al.; Fu et al. reply
This comment refered to the NATURE paper. Fu et al. have a later one in J.
Climate that offers greater detail. I wonder whether Tett & Thorne have
presented similar comments regarding this later paper.
[cut]
>
>You have thoroughly investigated C&S's work to the extent that you found a
>minor error. Are you now saying that your investigations were inadequate and
>C&S is all wrong? I am not arguing that C&S is perfect. Only that if the
>Z-model is better than that of Held & Soden, then that would explain Tett and
>Thorne's concerns.
I've only been able to look at a small part of S & C's data and found a
difference between the TLT and sonde data over the Antarctic. Whether that
difference is important is debateable, since the area of the Antarctic is
rather small compared to the total area of the Earth. I have suggested a
method to analyze the MSU/AMSU in order to seek clarification, but I can't
do the research. I simply don't have the resources or expertise to attack
the problem. Time will tell.
The fact remains that there are 5 different approaches to assessing climate
using the MSU data. I don't see that S & C's current results are more accurate
than the others and I find that their posturing and habit of glossing over
the problems in their many public statements only makes me more inclined to
reject their work. They seem to be playing to one side of the political
"debate", instead of presenting a balanced discussion. To me, they have
become the latest poster boys for "junk" science, along with Michaels, the
Idsos, and Balinuas, etc.
raylopez99
temperature has increased based on the U-shaped temperature gauge that
measures max, min temps every 24 hour time period. The only thing I
can think of is:
1) Heat island effects--towards the afternoon concrete absorbs heat and
radiates it
2) if the gauges are away from civilization, perhaps the weather has
become subject to more 'sharp spikes' over the last 50 years. Imagine
that once in a while a sharp spike in temperature occurs. This should
not affect mean temperature much if you measure mean temperature by
taking the area under the instantaneous temperature curve (by
integrating the curve, assuming proper Nyquist/Shannon sampling) and
dividing by time. However, if a sharp "Dirac" type 'impulse' occurs
once a day, then your crude U-shaped temperature gauge would register a
abnormally high temperature for a brief instant and skew the real
average temperature.
This is a fancy way of saying that a model that bases temperature
measurement on two samples a day is flawed; one should move to an
instantaneous temperature measurement model, which of course we have
not done over the past 50 years so the baseline to date is flawed. Of
course the hypothesis of sharp spikes in temperature caused by some
unknown new effect (but perhaps man made, like a afternoon 'heat
island' plume?) is pure conjecture and contrived.
RL
Coby Beck
I still don't see what aliasing has to do at all with the problem at hand.
Aliasing due to inadequate frequency of sampling will cause an incorrect
frequency of a flucuation to be recorded. The only danger I can see in the
case of temperature measurements would be coming up with an incorrect length
of the day-night cycle or seasons but no one is using temperature to
calculate that.
Temperature measurements are determining the absolute temperature not a rate
of flucuation. To take this into the realm of acoustics, you are trying to
fit a "square" problem that causes false frequency measurements into the
round physical attribute of absolute pressure. Aliasing does not effect
absolute air pressure measurements.
The only way you could get the kind of false trend you are proposing is by
accidentally measuring the temperature every day (on average) at a point
slightly higher in the daily flucuation than the day before. There are two
approaches I can think of off hand to avoid this. One is to simply take the
daily max and the daily min every day, the other is to measure at exactly
the same time every day. The first seems preferable and AFAIU is the norm.
The second would seem to be vulnerable only to a steady and gradual change
in the earth's rotation and/or orbit thereby causing a false trend.
--
Coby Beck
(remove #\Space "coby 101 @ bigpond . com")
Alastair McDonald
> The fact remains that there are 5 different approaches to assessing climate
> using the MSU data. I don't see that S & C's current results are more
accurate
> than the others
But I think I am right in saying that none of them come up with figures that
wholly support a straight lapse rate. The figures that come near have a
large discrepancy between the NH and the SH which cannot be explained
with a straight lapse rate. Moreover, Tett and Thorne agree that the figures
do not fit the tropics.
> and I find that their posturing and habit of glossing over
> the problems in their many public statements only makes me more inclined to
> reject their work. They seem to be playing to one side of the political
> "debate", instead of presenting a balanced discussion. To me, they have
> become the latest poster boys for "junk" science, along with Michaels, the
> Idsos, and Balinuas, etc.
I entirely agree! But that is not a reason to reject the science. What seems
to have happened is that by attacking AGW, C&S have attracted a major
effort to prove them wrong. But their assessment of the reason for the
discrepancy is wrong, not their data.
Why don't you help me to investigate the radiative convective models?
I would have thought that I have posted enough here for you to see they
are pretty flaky.
Cheers, Alastair.
Coby Beck
> It is clear from going through this thread that reputable,
> knowledgeable and respectible scientists are in disagreement over the
> exact mechanism for global warming, including but not limited to what
> the oceans absorb, what the upper atmosphere will do to C02 (whether
> the spectral line change will block or emit or otherwise alter the heat
> equation), and other such factors including possibly aliasing and
> calibration of different remote sensing devices, and possibly even heat
> island effects at measuring stations.
I haven't seen any "reputable, knowledgeable and respectible scientists"
giving any credence to your (is it yours) aliasing suggestion, nor to the
notion that heat island effects are either unaccounted for or significant.
raylopez99
is by
accidentally measuring the temperature every day (on average) at a
point
slightly higher in the daily flucuation than the day before. There are
two
approaches I can think of off hand to avoid this. One is to simply
take the
daily max and the daily min every day, the other is to measure at
exactly
the same time every day. The first seems preferable and AFAIU is the
norm. "
Yes, I agree. Probably aliasing is not a problem, see my earlier
post, unless you posit a sharp but brief "spike", ala a Dirac function
impulse, once a day, which would skew the true average temperature.
This spike is pure conjecture on my part, but I doubt anybody has
studied whether it exists. Possible human explanations of the 'spike'
would be a heat island plume toward the end of the day, when all the
pollution and junk accumulates and is baked by the sun. I would like
to see if instruments anywhere in the world have not detected a
increase in temperature, and where these instruments are.
Anybody know of the location of such "honest" instruments? I posit
that they would be away from civilization, possibly in South America
(Andes), Gobi desert, or Arctic, Antarctic regions.
RL
Eric Swanson
>
>
>"Eric Swanson" <swa...@notspam.net> wrote in message
>news:d2uqce$2ca6$1...@news3.infoave.net...
>
>> The fact remains that there are 5 different approaches to assessing climate
>> using the MSU data. I don't see that S & C's current results are more accurate
>> than the others
>
>But I think I am right in saying that none of them come up with figures that
>wholly support a straight lapse rate. The figures that come near have a
>large discrepancy between the NH and the SH which cannot be explained
>with a straight lapse rate. Moreover, Tett and Thorne agree that the figures
>do not fit the tropics.
The MSU data does not depend on a straight lapse rate. The instrument just
measures microwave radiation intensity at a frewuency. However, Spencer
& Christy's analysis apparently does so, and therein may be the problem, IMHO.
[cut]
>
>Why don't you help me to investigate the radiative convective models?
>I would have thought that I have posted enough here for you to see they
>are pretty flaky.
Start back in the 1970's and work forward. Should take you a few years...
raylopez99
> "raylopez99" <raylo...@yahoo.com> wrote in
news:1112687630.037134.39430
> @f14g2000cwb.googlegroups.com:
>
> > Thomas Palm wrote:
> >> "raylopez99" <raylo...@yahoo.com> wrote in
>
> > in physics but do you know how the GW standard model for climate
works?
>
> Only a very simple outline. I realize how much work it would be to
> understand them in a meaningful way, and even more to understand
enough
> to start finding real weaknesses in them.
>
You admit you do not understand the computer models for climate
forecasting, yet you trust your colleagues completely? Even when they
probably have used the same underlying 'climate engine' in all their
programs (being open source it is probably shared). So 10 out of 10
computer simulations of climate are in agreement, because they share
the same source code, and that makes it true? Your faith is greater
than of a medieval monk.
> > Anything is possible, I have found, if you throw enough money at
it.
> > The canonical model on GW could be received wisdom only because so
much
> > money has been invested in the model that alternate theories have
been
> > neglected.
>
> What alternative models? You can't research anything unless you have
any
> idea what it might be!
The model would be to construct a model where mankind is NOT the prime
source of global warming, and see if such a model can relate to what
has been measured. If one can construct such a model, ergo you cannot
exclude non-manmade causes for global warming. Give me $10 million and
I will put together a consortium to build such a model.
>
>
> Basing world growth on the assumption that the best available science
is
> wrong is a lot more likely to be disastrous, though. There simply
isn't
> any 100% certainty in any decisions made, yet decisions have to be
made.
> You may pretend that continuing to emit more and more CO2 is "doing
> nothing" but that too will have disastrous consequences if science is
> right.
>
And if the science is wrong? WWIII.
> > The bottom line is this: do you trust a computer simulation to
predict
> > a complex (chaotic, non-linear, feedback driven) system like the
> > earth's atmosphere, when scientists have problems predicting exact
> > motion in the so-called "three body" problem of physics?
>
> People may have problem with the three body problem, but do you trust
> thermodynamics? There you have billions and billions of particles,
yet
> people can make models that work to good accuracy. They do this by
> calculating the averages, and this is what climate science does too.
The
> chaos is found in the weather, but on longer timescales climate is a
lot
> more stable.
>
But you ignore 'heat island' effects and 'late afternoon spikes' in
temperature that may produce aliasing (just a hypothesis of mine).
> > I'm not
> > making fun of physics, just saying that any model has assumptions
and
> > holes, that can be challenged. Nothing is absolute. Something
about
> > Carl Popper comes to mind, but I'm too tired to Google it.
>
> Do you fly? Are you sure there isn't some flaw in aerodynamics that
will
> make your plane crash? Like it or not, your life depends on science
being
> a workable process to gain knowledge. You can't just use these
general
> attack on the scientific method when it comes to climate science and
> still trust it everywhere else.
>
Big difference: airplanes have been tested in wind tunnels and
actually flown. Climate models are only 'tested' in somebody's
computer RAM.
> Do you want to base your life on the assumption that that
supercomputer
> simulation is wrong? That simpler models run on personal computers
are
> wrong? That even the most simple models that you can do by pen and
paper
> are wrong? The fact is that you get global warming in everything from
> simple 1D models to the most complex 3D GCM:s.
No, because the models are all cut from the same cloth, see my earlier
remark.
RL
raylopez99
fears.
Below is an excerpt.
Ray Lopez
--
Further work is required to improve the ability to detect, attribute,
and understand climate change, to reduce uncertainties, and to project
future climate changes. In particular, there is a need for additional
systematic observations, modelling and process studies. A serious
concern {SERIOUS CONCERN!!!--WOW WHAT AN ADMISSION! RAY} is the decline
of observational networks. Further work is needed in eight broad areas:
* Reverse the decline of observational networks in many parts of
the world. Unless networks are significantly improved, it may be
difficult or impossible to detect climate change over large parts of
the globe. {AND WHAT WAS THE HEALTH OF THE NETWORKS PRIOR TO TODAY? I
POSIT THAT THE HEATHIEST NETWORKS WERE IN INDUSTRIAL COUNTRIES, NEAR
AIRPORTS, THAT ARE SUBJECT TO HEAT ISLAND EFFECTS--RL}
* Sustain and expand the observational foundation for climate
studies by providing accurate, long-term, consistent data including
implementation of a strategy for integrated global observations. Given
the complexity of the climate system and the inherent multi-decadal
time-scale, there is a need for long-term consistent data to support
climate and environmental change investigations and projections. Data
from the present and recent past, climate-relevant data for the last
few centuries, and for the last several millennia are all needed. There
is a particular shortage of data in polar regions and data for the
quantitative assessment of extremes on the global scale. [JUST AS I
SUSPECT--THE POLAR REGIONS, WHERE MANKIND IS NOT PRESENT, HAVE THE
SPARSEST DATA]
* Understand better the mechanisms and factors leading to changes
in radiative forcing; in particular, improve the observations of the
spatial distribution of greenhouse gases and aerosols. It is
particularly important that improvements are realised in deriving
concentrations from emissions of gases and particularly aerosols, and
in addressing biogeochemical sequestration and cycling, and
specifically, in determining the spatial-temporal distribution of
carbon dioxide (CO2) sources and sinks, currently and in the future.
Observations are needed that would decisively improve our ability to
model the carbon cycle; in addition, a dense and well-calibrated
network of stations for monitoring CO2 and oxygen (O2) concentrations
will also be required for international verification of carbon sinks.
Improvements in deriving concentrations from emissions of gases and in
the prediction and assessment of direct and indirect aerosol forcing
will require an integrated effort involving in situ observations,
satellite remote sensing, field campaigns and modelling. [SOUNDS LIKE
CLIMATEOLOGY IS IN ITS INFANCY TO ME--RL]
* Understand and characterise the important unresolved processes
and feedbacks, both physical and biogeochemical, in the climate system.
Increased understanding is needed to improve prognostic capabilities
generally. The interplay of observation and models will be the key for
progress. The rapid forcing of a non-linear system has a high prospect
of producing surprises. [THANK YOU FOR THIS ADMISSION THAT GLOBAL
WARMING COULD BE A FLASH IN THE PAN--RL]
* Address more completely patterns of long-term climate variability
including the occurrence of extreme events. This topic arises both in
model calculations and in the climate system. In simulations, the issue
of climate drift within model calculations needs to be clarified better
in part because it compounds the difficulty of distinguishing signal
and noise. With respect to the long-term natural variability in the
climate system per se, it is important to understand this variability
and to expand the emerging capability of predicting patterns of
organised variability such as El Niño-Southern Oscillation (ENSO).
This predictive capability is both a valuable test of model performance
and a useful contribution in natural resource and economic management.
[YES, A LOW SIGNAL-TO-NOISE RATIO IS AN ADMISSION THAT THE INSTRUMENTS
ARE FLAWED--WHAT DO YOU EXPECT WHEN YOU ARE DEALING WITH CO2 AND
TEMPERATURE MEASURING INSTRUMENTS THAT SPAN AT LEAST 2 GENERATIONS (50
YEARS) AND NUMEROUS SATELLITE INSTRUMENTS THAT WERE NOT MEANT TO
MEASURE LONG TERM TRENDS? RL]
* Improve methods to quantify uncertainties of climate projections
and scenarios, including development and exploration of long-term
ensemble simulations using complex models. The climate system is a
coupled non-linear chaotic system, and therefore the long-term
prediction of future climate states is not possible. Rather the focus
must be upon the prediction of the probability distribution of the
system's future possible states by the generation of ensembles of
model solutions. Addressing adequately the statistical nature of
climate is computationally intensive and requires the application of
new methods of model diagnosis, but such statistical information is
essential. [YES, GAUSSIAN STATISTICS ARE A GOOD START BUT NOT
DEFINITIVE--YOU CAN HAVE 'FAT TAILS' --RL]
* Improve the integrated hierarchy of global and regional climate
models with a focus on the simulation of climate variability, regional
climate changes, and extreme events. There is the potential for
increased understanding of extremes events by employing regional
climate models; however, there are also challenges in realising this
potential. It will require improvements in the understanding of the
coupling between the major atmospheric, oceanic, and terrestrial
systems, and extensive diagnostic modelling and observational studies
that evaluate and improve simulation performance. A particularly
important issue is the adequacy of data needed to attack the question
of changes in extreme events. [WOW! LOTS OF WORK NEEDS TO BE DONE
BEFORE WE CAN ASSUME GLOBAL WARMING IS MAN-MADE--RL]
* Link models of the physical climate and the biogeochemical system
more effectively, and in turn improve coupling with descriptions of
human activities. At present, human influences generally are treated
only through emission scenarios that provide external forcings to the
climate system. In future more comprehensive models, human activities
need to begin to interact with the dynamics of physical, chemical, and
biological sub-systems through a diverse set of contributing
activities, feedbacks, and responses. [YES, EXTERNAL FORCINGS DON'T
ACCOUNT FOR NEGATIVE FEEDBACK PROVIDED BY MOTHER NATURE--RL]
Cutting across these foci are crucial needs associated with
strengthening international co-operation and co-ordination in order to
utilise better scientific, computational, and observational resources.
This should also promote the free exchange of data among scientists. A
special need is to increase the observational and research capacities
in many regions, particularly in developing countries. Finally, as is
the goal of this assessment, there is a continuing imperative to
communicate research advances in terms that are relevant to decision
making. [DO I DETECT 'TURF WARS' BETWEEN SCIENTIFIC GROUPS THAT
PREVENTS THE FREE-FLOW OF INFORMATION? I THINK I DO--RL]
The challenges to understanding the Earth system, including the human
component, are daunting, but these challenges simply must be met. [YES
I AGREE. AND UNTIL THESE SERIOUS CONCERNS _are_ MET, THE USA CANNOT
SIGN ONTO KYOTO--RL]
Alastair McDonald
> In article <d2urki$udu$1...@newsg1.svr.pol.co.uk>,
alas...@abmcdonald.leavethisout.freeserve.co.uk says...
> >
> >
> >"Eric Swanson" <swa...@notspam.net> wrote in message
> >news:d2uqce$2ca6$1...@news3.infoave.net...
> The MSU data does not depend on a straight lapse rate. The instrument just
> measures microwave radiation intensity at a frewuency. However, Spencer
> & Christy's analysis apparently does so, and therein may be the problem,
IMHO.
I am not saying the MSU data depends on a straight lapse rate <grrr> I am
saying that the models which predict that the troposphere should warm at the
same rate or faster than the surface (Held and Soden 2000 Fig 1) depend on
a straight lapse rate. If you don't like that ref. then check out "The physics
of
atmospheres" by John Houghton, 1977, Fig 2.4.
> [cut]
> >
> >Why don't you help me to investigate the radiative convective models?
> >I would have thought that I have posted enough here for you to see they
> >are pretty flaky.
>
> Start back in the 1970's and work forward. Should take you a few years...
I have already worked my way back to 1910, but if you are happy going
over the same old ground with the MSU readings, along with all those other
scientists, rather than trying a new approach, then good luck to you.
Cheers, Alastair.
Coby Beck
> And there's a possiblity that all are wrong, since, being open-source,
> they probably copy the same formulaes used?
While it is only human nature to assume that the way we personally think and
approach life's challenges is universal to all of us, it is at the same time
a misleading fallacy. The sooner you understand this, the farther you will
go in life.
Coby Beck
> probably have used the same underlying 'climate engine' in all their
> programs (being open source it is probably shared). So 10 out of 10
> computer simulations of climate are in agreement, because they share
> the same source code
> No, because the models are all cut from the same cloth, see my earlier
> remark.
So I suppose you will now add this to your list of things "that reputable,
knowledgeable and respectible scientists are in disagreement over", the
cut-n-paste computer code bias effect? Right after the "late afternoon
super heat spike" phenonemon...
Raymond Arritt
> And there's a possiblity that all are wrong, since, being open-source,
> they probably copy the same formulaes used?
No, they don't use the same formulas. There's a good variety of
different parameterization schemes and numerical methods.
To repeat, the projection of increased warming over the remainder of
this century is a robust finding in the sense that different GCMs using
different assumptions and formulations all predict warming.
And yes, all the models are wrong. All physics is wrong, because we
don't yet know everything. We are fully aware that Newtonian mechanics
is wrong in an absolute sense but airplanes designed on the basis of
Newtonian physics still fly. We will never be able to predict the
motion of each neutron released during the process of radioactive decay
but we know that storing 60 kg of U235 in one place is not smart. The
useful question is not whether any given model is right or wrong,
because we know it's impossible to create a perfect model of anything.
Raymond Arritt
> "Eric Swanson" <swa...@notspam.net> wrote in message
> news:d2v2sa$2gfc$1...@news3.infoave.net...
>> In article <d2urki$udu$1...@newsg1.svr.pol.co.uk>,
> alas...@abmcdonald.leavethisout.freeserve.co.uk says...
>> >
>> >
>> >"Eric Swanson" <swa...@notspam.net> wrote in message
>> >news:d2uqce$2ca6$1...@news3.infoave.net...
>
>> The MSU data does not depend on a straight lapse rate. The instrument just
>> measures microwave radiation intensity at a frewuency. However, Spencer
>> & Christy's analysis apparently does so, and therein may be the problem,
> IMHO.
>
> I am not saying the MSU data depends on a straight lapse rate <grrr> I am
> saying that the models which predict that the troposphere should warm at the
> same rate or faster than the surface (Held and Soden 2000 Fig 1) depend on
> a straight lapse rate. If you don't like that ref. then check out "The physics
> of
> atmospheres" by John Houghton, 1977, Fig 2.4.
Several times you've cited Fig. 1 in the Held and Soden review, but
you've apparently mistaken a simplified schematic diagram for a proposed
"model" of the atmosphere. Certainly Isaac Held (of all people) knows
that the atmospheric lapse rate seldom if ever follows a straight line!
Thomas Palm
news:1112730243.0...@l41g2000cwc.googlegroups.com:
Hey, Ray, then it is good that you don't have any credibility yourself,
isn't it, or I might be hurt by your insult? You referenced *a*
derivation that used a Taylor expansion, and as I explained it wasn't a
very good explanation since it started with an equation for the kinetic
energy that is in itself an approximation. I actually looked the
derivation up in my old textbook in relativity theory and you can dervie
it without any such approximations. I'm not giong to type in all of the
derivation, though.
> Below is another reference, repeated in full.
> This makes me wonder--who is the expert here? I haven't done this
> derivation since over 20 years ago (how times does fly!) but I still
> remember it.
So you remember a bad derivation while I look up a good one. (I could
have derived a bad one too. It's not hard). That makes me the smarter
person because I realize my limitations.
> And now I'm supposed to believe you 'experts' in a much more complex
> question called Global Warming? :-)
I frankly don't give a damn about what you believe. You are too arrogant
to learn anything anyway.
> http://www.madsci.org/posts/archives/apr2000/956844514.Ph.r.html
Fine, you've found another site facing the same constraint that they need
to get to the equation in short space using the minimum number of
assuptions.
Thomas Palm
news:1112740364.3...@g14g2000cwa.googlegroups.com:
> Thomas Palm wrote:
>> "raylopez99" <raylo...@yahoo.com> wrote in
> news:1112687630.037134.39430
>> > Seems like you are an expert
>> > in physics but do you know how the GW standard model for climate
> works?
>>
>> Only a very simple outline. I realize how much work it would be to
>> understand them in a meaningful way, and even more to understand
> enough
>> to start finding real weaknesses in them.
>>
>
> You admit you do not understand the computer models for climate
> forecasting, yet you trust your colleagues completely? Even when they
> probably have used the same underlying 'climate engine' in all their
> programs (being open source it is probably shared). So 10 out of 10
> computer simulations of climate are in agreement, because they share
> the same source code, and that makes it true? Your faith is greater
> than of a medieval monk.
I know enough to be aware that the different simulators do not share the
same code.
>> What alternative models? You can't research anything unless you have
> any
>> idea what it might be!
>
> The model would be to construct a model where mankind is NOT the prime
> source of global warming, and see if such a model can relate to what
> has been measured.
People have tried removing all antrophogenic inputs into the models, of
course, and the result is that they don't match observations.
> If one can construct such a model, ergo you cannot
> exclude non-manmade causes for global warming. Give me $10 million and
> I will put together a consortium to build such a model.
Ask the fossil fuel industry or one of their lobby organizations. They
might be despearate enough to hire someone like you. Serious
organizations expect people to show their competence in understanding the
basic problem first before handing over that kind of money.
>> Basing world growth on the assumption that the best available science
> is
>> wrong is a lot more likely to be disastrous, though. There simply
> isn't
>> any 100% certainty in any decisions made, yet decisions have to be
> made.
>> You may pretend that continuing to emit more and more CO2 is "doing
>> nothing" but that too will have disastrous consequences if science is
>
>> right.
>>
>
> And if the science is wrong? WWIII.
Nonsense! If the science is wrong we have possibly wasted some money, but
on the other hand we may have avoided WW III by reducing pressure on the
last oil resources. If the science is right and we continue as before, on
the other hand, then WW III is a possible consequence.
>> > The bottom line is this: do you trust a computer simulation to
> predict
>> > a complex (chaotic, non-linear, feedback driven) system like the
>> > earth's atmosphere, when scientists have problems predicting exact
>> > motion in the so-called "three body" problem of physics?
>>
>> People may have problem with the three body problem, but do you trust
>
>> thermodynamics? There you have billions and billions of particles,
> yet
>> people can make models that work to good accuracy. They do this by
>> calculating the averages, and this is what climate science does too.
> The
>> chaos is found in the weather, but on longer timescales climate is a
> lot
>> more stable.
>>
>
> But you ignore 'heat island' effects and 'late afternoon spikes' in
> temperature that may produce aliasing (just a hypothesis of mine).
I don't ignore the heat island effect, but unlike you I know that it was
discussed and taken into account already in the mid 70:s. Your "spike"
theory I'm going to ignore unless you can come up with any kind of
support for it, and make sure that that support doesn't contradict
measurements that have been made. For example, some stations has both a
max-min thermometer and continous readings and such a spike should have
been discovered.
> Big difference: airplanes have been tested in wind tunnels and
> actually flown. Climate models are only 'tested' in somebody's
> computer RAM.
Do read a little bit on how you test these computer models.
>> Do you want to base your life on the assumption that that
> supercomputer
>> simulation is wrong? That simpler models run on personal computers
> are
>> wrong? That even the most simple models that you can do by pen and
> paper
>> are wrong? The fact is that you get global warming in everything from
>
>> simple 1D models to the most complex 3D GCM:s.
>
> No, because the models are all cut from the same cloth, see my earlier
> remark.
But your earlier argument was nonsense as just about everything else you
say. You really need to learn that your guesses aren't science.
raylopez99
> raylopez99 wrote:
> > And there's a possiblity that all are wrong, since, being
open-source,
> > they probably copy the same formulaes used?
>
> No, they don't use the same formulas. There's a good variety of
> different parameterization schemes and numerical methods.
>
> To repeat, the projection of increased warming over the remainder of
> this century is a robust finding in the sense that different GCMs
using
> different assumptions and formulations all predict warming.
>
>
your opinion, these formulaes are NOT representative of the global
warming calculations done today in simulations.
Bottom line: the assumptions are largely the same.
RL
go here: http://www.john-daly.com/bull-121.htm
The greenhouse effect is considered to be caused by the absorption of
long wave (infra red) radiation from the earth by trace gases in the
atmosphere. Changes in the concentration of these gases leads to a
change in the radiative energy absorbed, and thus of the temperature of
the atmosphere, and of its radiation back to earth. The difference in
radiation received by the earth between two defined conditions is
called radiative forcing. There are two important examples. The first
is the forcing thought to be caused by the combustion of fossil fuels
since the large scale development of industry which is considered to be
responsible for an increase in atmospheric carbon dioxide concentration
over an assumed "pre-industrial" level. The second, commonly calculated
by computer climate models, is the forcing produced by doubling the
concentration of carbon dioxide in the atmosphere. The forcing can be
converted to a mean global surface temperature change by multiplying by
a "climate sensitivity" parameter which varies widely between the
different models. The IPCC (Houghton et al. 1990) has amalgamated
forcing and its global temperature response into a range of
"temperature climate sensitivities" for the doubling of carbon dioxide
concentration in the atmosphere, as estimated by the different computer
climate models, for which the "Best Estimate" is 2.5°C, the "High
Estimate" 4.5°C, and the "Low Estimate" 2.5°C.
w...@bas.ac.uk
>And there's a possiblity that all are wrong, since, being open-source,
>they probably copy the same formulaes used?
Given that some are finite difference and some are spectral, this would
be impossible. And some (hadcm3) are definitely not open source.
Why don't you find out what FD and S are, since you're clearly interested
in all this?
-W.
--
William M Connolley | w...@bas.ac.uk | http://www.antarctica.ac.uk/met/wmc/
Climate Modeller, British Antarctic Survey | Disclaimer: I speak for myself
I'm a .signature virus! copy me into your .signature file & help me spread!
w...@bas.ac.uk
Well done - you found the IPCC report, and you've discovered that
(unlike the skeptics) they are open and honest about the state of
climate science. But you've managed to selectively quote it, of course,
to pick out only the uncertainties. This is the std.septic policy.
>the globe. {AND WHAT WAS THE HEALTH OF THE NETWORKS PRIOR TO TODAY? I
>POSIT THAT THE HEATHIEST NETWORKS WERE IN INDUSTRIAL COUNTRIES, NEAR
>AIRPORTS, THAT ARE SUBJECT TO HEAT ISLAND EFFECTS--RL}
But here you have failed. The IPCC report discusses UHI, so if you were
actually interested, as your shouting suggests, you would have read
up on it.
>quantitative assessment of extremes on the global scale. [JUST AS I
>SUSPECT--THE POLAR REGIONS, WHERE MANKIND IS NOT PRESENT, HAVE THE
>SPARSEST DATA]
Wow! Really? You realise how silly you're sounding?
> * Understand and characterise the important unresolved processes
>and feedbacks, both physical and biogeochemical, in the climate system.
>Increased understanding is needed to improve prognostic capabilities
>generally. The interplay of observation and models will be the key for
>progress. The rapid forcing of a non-linear system has a high prospect
>of producing surprises. [THANK YOU FOR THIS ADMISSION THAT GLOBAL
>WARMING COULD BE A FLASH IN THE PAN--RL]
Why are you so determined to misinterpret things?
>of changes in extreme events. [WOW! LOTS OF WORK NEEDS TO BE DONE
>BEFORE WE CAN ASSUME GLOBAL WARMING IS MAN-MADE--RL]
The current view is somewhat stronger than balance-of-evidence. But all
that is extenisvely discussed.
James Annan
> raylopez99 <raylo...@yahoo.com> wrote:
>
>>And there's a possiblity that all are wrong, since, being open-source,
>>they probably copy the same formulaes used?
>
>
> Given that some are finite difference and some are spectral, this would
> be impossible. And some (hadcm3) are definitely not open source.
>
> Why don't you find out what FD and S are, since you're clearly interested
> in all this?
He's clearly interested only in throwing as much shit as possible in the
vain hope that some of it might stick. But he's shown a lamentably poor
aim so far.
James
Alastair McDonald
<w...@bas.ac.uk> wrote in message news:4253...@news.nwl.ac.uk...
> raylopez99 <raylo...@yahoo.com> wrote:
> >And there's a possiblity that all are wrong, since, being open-source,
> >they probably copy the same formulaes used?
>
> Given that some are finite difference and some are spectral, this would
> be impossible. And some (hadcm3) are definitely not open source.
>
> Why don't you find out what FD and S are, since you're clearly interested
> in all this?
He claimed he was going to read "Weather Cycles" but then admitted
that was a lie. James has got it right. Ray's just a troll enjoying himself.
Cheers, Alastair.
Raymond Arritt
> Raymond Arritt wrote:
>> To repeat, the projection of increased warming over the remainder of
>> this century is a robust finding in the sense that different GCMs
> using
>> different assumptions and formulations all predict warming.
>>
>>
> Raymond--please go here and review these formulaes, and tell me if, in
> your opinion, these formulaes are NOT representative of the global
> warming calculations done today in simulations.
>
OK, in the words you asked for: "These formulas are NOT representative
of the global warming calculations done today in simulations."
The formulas given in the web page you cite are approximations derived
as an aid to understanding the results from a variety of models. They
are not actually used within the models to calculate radiative transfer.
The radiation parameterizations used in the models are far more
detailed, and vary from model to model.
Lloyd Parker
"raylopez99" <raylo...@yahoo.com> wrote:
>Raymond Arritt wrote:
>> raylopez99 wrote:
>> > And there's a possiblity that all are wrong, since, being
>open-source,
>> > they probably copy the same formulaes used?
>>
>> No, they don't use the same formulas. There's a good variety of
>> different parameterization schemes and numerical methods.
>>
>> To repeat, the projection of increased warming over the remainder of
>> this century is a robust finding in the sense that different GCMs
>using
>> different assumptions and formulations all predict warming.
>>
>>
>Raymond--please go here and review these formulaes, and tell me if, in
>your opinion, these formulaes are NOT representative of the global
>warming calculations done today in simulations.
>
>Bottom line: the assumptions are largely the same.
>
>RL
>
>go here: http://www.john-daly.com/bull-121.htm
>
Oh Jeez, he cites a creationist site!
raylopez99
review of it that he predicts climate is chaotic. This implies sudden
spikes in temperature (recall how even on a sunny day or on 'calm seas'
you will sometimes get a monster wave that will crash over a boat or
wash up to the lifeguard's stand. This is chaotic/non-linear behavior)
Coupled with the UHI (see http://www.warwickhughes.com/climate/ ) it
seems to me that the consensus should realise that GW is a fallacy, at
best a statistical anomaly, and probably due to UHI and instrument
error.
Also read the thread on the Cato Institute and CNN report on GW that
downplayed two scientists who point out the increase in temperature is
nearly statistical noise.
And yes the climate 'engines' are all based on the CO2 as trigger
hypothesis (ignoring how aerosols can also be triggers, in fact
converting water vapour and aerosols into 'equivalent CO2' which sounds
like a fudge factor). Consequently the models are all cut from the
same cloth.
When will the scales drop from your eyes? Or are you really so clever
to think we don't see you have a hidden agenda?
On the GW payroll Alastair?
raylopez99
I think all these models target CO2 as the trigger, based on Arrhenius'
original paper, and all are therefore biased.
For example, water vapour, aerosols, and the like are thought of as
"equivalent CO2" yet they clearly have different spectral absorption
lines. A nice way of fudging the effect of these 'greenhouse gases'
(naturally made, like sea spray) without having to do the hard science.
And let's not even mention aliasing, UHI, and uncalibrated instruments.
Does anybody even know how the Keeling CO2 instrument works? Or is it
an article of faith amongst the disciples of GW that it works as
warranted?
What a crock. Shame on you GW advocates. A pox on your head and house.
Only consolation is that as long as there is a Republican
administration, and even once they leave, America will not sacrifice
its growth to test an unproven computer simulation. So nobody is
paying attention to you GW nuts.
RL
Alastair McDonald
> I haven't yet received Burrough's book Alastair. Sounds from the
> review of it that he predicts climate is chaotic. This implies sudden
> spikes in temperature (recall how even on a sunny day or on 'calm seas'
> you will sometimes get a monster wave that will crash over a boat or
I named the Tiamat hypothesis, which proposes that the Earth's climate
is kept within a habitable range of temperature by the runaway water
vapour greenhouse effect held in check by the effect of clouds. The
hypothesis had already been proposed separately by Ou and Wally
Broecker. The Tiamat Hypothesis can be seen as opposing or
complimenting the Gaia Hypothesis which ever take your fancy, but
whereas Gaia was a mother goddess, Tiamat was a male god of
chaos and destruction.
> Coupled with the UHI (see http://www.warwickhughes.com/climate/ ) it
> seems to me that the consensus should realise that GW is a fallacy, at
> best a statistical anomaly, and probably due to UHI and instrument
> error.
>
> Also read the thread on the Cato Institute and CNN report on GW that
> downplayed two scientists who point out the increase in temperature is
> nearly statistical noise.
Why don't you read the NOAA site, the NASA site, the AGU statement,
the Geological Society statement, even the Australian CSIRO have a
global warming warning.
> And yes the climate 'engines' are all based on the CO2 as trigger
> hypothesis (ignoring how aerosols can also be triggers, in fact
> converting water vapour and aerosols into 'equivalent CO2' which sounds
> like a fudge factor). Consequently the models are all cut from the
> same cloth.
Water vapour is handled as a feedback, because its concentration
depends on temperature. As global sea surface temperatures rise
due to CO2, the amount of water vapour in the air increases. Water
vapour is a greenhouse gas, therefore the sea surface temperatures
rise even further. That means yet more water vapour and yet more
warming. The scientists do not know how much the increase in water
vapour will be for an increase in CO2, or for methane, or for any of
the other greenhouse gases. But it is more likely that they are under
estimating this positive feedback rather than over estimating it
because they tend to be conservative. Basically, once it is obvious
that anthropogenic global warming is happening it will be too late to
stop a disaster happening. Some of us think it is obvious now.
> When will the scales drop from your eyes? Or are you really so clever
> to think we don't see you have a hidden agenda?
> On the GW payroll Alastair?
Unlike the more authorities of your critics, I am not on the GW payroll
much as I would love to be. I am only doing this out of a sense of
duty to save the world. Sometimes I wonder if it is really worth it :-(
Cheers, Alastair.
w...@bas.ac.uk
>And yes the climate 'engines' are all based on the CO2 as trigger
>hypothesis (ignoring how aerosols can also be triggers, in fact
>converting water vapour and aerosols into 'equivalent CO2' which sounds
>like a fudge factor).
Errrmmm... when did you get that from? Its not true.
Do let us know when you understand the difference between FD/S.
_W.
Raymond Arritt
> Why don't you just tell me? FD = FUD?
FD = finite difference. One approach to the numerical solution of
partial differential equations.
> I think all these models target CO2 as the trigger, based on Arrhenius'
> original paper, and all are therefore biased.
It's not clear what you're getting at. Obviously they include the
effect of CO2 (as all climate models must), but it's a bit odd to think
of CO2 as a "trigger" which gives the impression of an on/off switch.
The effect of CO2 is continuous; more specifically, its radiative effect
scales roughly with the logarithm of concentration.
> For example, water vapour, aerosols, and the like are thought of as
> "equivalent CO2" yet they clearly have different spectral absorption
> lines.
No, water vapor and aerosols aren't thought of as "equivalent CO2."
raylopez99
http://www.carbonwatch.com/calculator%20-%20GHG.htm
Note Sf6 (Sulfur Hexafluoride), N2o (Nitrous oxide); Cf4
(Tetrafluoromethane), all aerosols, are considered "equivalent CO2" for
the Arrhenius (flawed) model.
BTW sulfate aerosols actually produce negative feedback and reduce
global warming.
I stand corrected about water vapour--apparently it is only considered
a feedback agent. (At least I admit my mistakes).
BTW, a global warming research site makes this concession: "Probably
only 2/3 of the warming is human made, the rest is solar forcing." --
imagine that--Global Warming caused by Mother Nature as offender.
And these concessions:
"Positive feedbacks make Earth highly vulnerable to climate changes,
and rising levels of GHGs will cause unprecedented changes that will
lead to disasters. It's overstated because:
There is the negative feedback of chemical weathering on very
long time scales
On much shorter time scales, there is the negative feedbacks
from clouds and aerosols.
Climate system is not completely understood, such as
vegetation feedbacks or millennial-scale climate oscillations"
raylopez99
Basically the problem I have with the Parker and Peterson
studies--which I have not read but in abstract form--are that they
clearly ignore UHI by assuming it away. Essentially both papers say
"We cannot detect UHI between town and countryside so it must not
exist". This is clearly wrong--both town and countryside have become
populated with concrete over the last 50 years--so they are sometimes
nearly indistinquishable. And Peterson himself says: "This is not to
say that Urban Heat Islands do not exist. Major highway intersections
and industrial centers of cities may well be significantly warmer than
rural areas," said Peterson. But weather stations are more likely to
be located in parks than industrial areas and other research has
indicated that urban parks can be significantly cooler than the
industrial parts of towns." Essentially Peterson, without
elaborating, is saying that city temperature measuring stations are
found in shady parks. Nice thought, but I don't buy it. Then we must
assume that a shady park will not be affected by convection and
radiation from a hot skyscraper next door. If you believe that, I have
a bridge in Brooklyn I'd like to sell you. Any idiot can sense that if
NYC was as the Manhattan Indians left it, with no buildings, Central
Park would be at least 1 degree cooler than today. You can model that
with a PC much less a supercomputer and come to that conclusion. Did
Peterson and Parker have a control group where no buildings were
present? No. THey "assumed away" the problem by saying they cannot
detect differences, ergo they must not exist. THis violates the laws
of thermodynamics.
Further Parker ignored the effects of convection by apparently using
inaccurate satellites to measure temperature--this is wrong too.
Also for the IPCC report--the UHI was not mentioned (or if it is I
could not find it).
I did read the IPCC report, which apparently even wants to classify
tilling the soil as a harmful 'forcing function' that impacts global
warming. I guess the IPCC would rather we all die.
RL
w...@bas.ac.uk
>Also for the IPCC report--the UHI was not mentioned (or if it is I
>could not find it).
Why oh why do you revel in your ignorance in this way? The IPCC section
on UHI is clearly ref'd from the wiki page, even if you couldn't
find it directly.
If this is too difficult for you, then try:
http://www.grida.no/climate/ipcc_tar/wg1/052.htm#2221
Coby Beck
...[UHI study]
> present? No. THey "assumed away" the problem by saying they cannot
> detect differences, ergo they must not exist.
I think the study said they cannot detect the difference therefore the
difference is not detectable. Not such a leap, is it, even for RL...?
> Also for the IPCC report--the UHI was not mentioned (or if it is I
> could not find it).
try google: <"urban heat island" site:www.grida.no>
Coby Beck
<w...@bas.ac.uk> wrote in message news:4256...@news.nwl.ac.uk...
> raylopez99 <raylo...@yahoo.com> wrote:
>>Also for the IPCC report--the UHI was not mentioned (or if it is I
>>could not find it).
>
> Why oh why do you revel in your ignorance in this way? The IPCC section
> on UHI is clearly ref'd from the wiki page, even if you couldn't
> find it directly.
>
> If this is too difficult for you, then try:
>
> http://www.grida.no/climate/ipcc_tar/wg1/052.htm#2221
I even posted this same link for him days ago in another thread.