Delta T_u-r(max)=1.42log_10(POP)-2.09

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Greenhouse

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May 27, 2003, 10:46:31 PM5/27/03
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Delta T_u-r(max)=1.42log_10(POP)-2.09

There's nothing so authoritative-looking as a mathematical formula. It
proclaims exactness, precision, and appears more credible than mere words,
even where the reader might not understand what the formula says.

This particular formula comes from a paper published in the Australian
Meteorological Magazine (v.50, 2001, 1-13) titled `Urban Heat Island
Features of Southeast Australian Towns', authored by Torok et al. The
formula is the outcome of a study by four researchers into the magnitude of
heat island effects in four small towns in south-eastern Australia and
states a general rule for estimating urban heat islands in such towns from
local data.

The authors acknowledged that Melbourne (3 million+ population) had a
maximum urban-rural temperature difference (Tu-r(max)) of 6.8°C based on a
previous study, and that even Hobart with only 130,000 people had a
Tu-r(max) of 5.7°C. That effectively damns all large and medium size cities
as credible places from which to detect the fractions of a degree changes
needed for detection of genuine climate change.

But what of the small towns? Torok et al. tested Hamilton (pop. 9,753),
Colac (pop. 9,171), Cobden (pop. 1,477) and Camperdown (pop. 3,315). The
results showed differences between town and rural to vary between 1°C and
5.4°C. The researchers also found a significant difference between
measurements taken over concrete and taken over grass, the heat island being
moderated if the weather box is located on a grassy expanse.

These small towns have populations which would designate them as `rural' in
the CRU and GISS datasets and yet have significant heat islands which would
invalidate their use as places to detect climate change using local
temperature data. The data from all these towns would remain uncorrected
for heat islands even though the phenomenon is running into urban-rural
differences of whole degrees for all of them.

The authors concluded -

"these results imply that climatological stations in large cities should
preferably be excluded from studies into long-term climate change, and those
in small towns should be located away from the town centres."

It's about time the IPCC and the keepers of the surface data, CRU and GISS,
took the urban heat island seriously enough to review all weather records
from around the world and make a thorough purge of those records emanating
from not only large cities, but also from small towns. Since even small
Australian towns are shown to have a significant urbanisation distortion to
the data, then the more tightly packed towns of Europe and North America
will show even more severe effects.

To promote `global warming' to the public, the public must be first assured
that the data they are presented with is not simply an aggregate of
thousands of localised urban warmings. `Greenfields' stations are few in
number, but collectively they would present a more accurate picture of
climate trends than do the hopelessly contaminated data from urban areas,
even the small ones.

The paper itself was originally submitted to Australian Meteorological
Magazine in December 1998 and was not published until March 2001 - a very
long time lag between submission and publication, even for that journal.
This contrasts with the eager fast-tracking that pro-warming papers receive
from the major journals.


Ian St. John

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May 27, 2003, 11:44:36 PM5/27/03
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"Greenhouse" <Green...@greenhouse.net> wrote in message
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> Delta T_u-r(max)=1.42log_10(POP)-2.09
>
> There's nothing so authoritative-looking as a mathematical formula. It
> proclaims exactness, precision, and appears more credible than mere words,
> even where the reader might not understand what the formula says.
>
> This particular formula comes from a paper published in the Australian
> Meteorological Magazine (v.50, 2001, 1-13) titled `Urban Heat Island
> Features of Southeast Australian Towns', authored by Torok et al. The
> formula is the outcome of a study by four researchers into the magnitude
of
> heat island effects in four small towns in south-eastern Australia and
> states a general rule for estimating urban heat islands in such towns from
> local data.
>
> The authors acknowledged that Melbourne (3 million+ population) had a
> maximum urban-rural temperature difference (Tu-r(max)) of 6.8°C based on a
> previous study, and that even Hobart with only 130,000 people had a
> Tu-r(max) of 5.7°C.

Neat formula. I imagine it needs adjustment for local climate since heating
and cooling needs are not that uniform. Probably works only in the
Australian microclimates.

> That effectively damns all large and medium size cities
> as credible places from which to detect the fractions of a degree changes
> needed for detection of genuine climate change.

Here is where the bullshit starts. The urban heat island effect is well
evaluated on a station by station basis and the effect removed before
processing. Nor is the statement that it creates large error bars supported
by the facts.

<snip>


>
> The paper itself was originally submitted to Australian Meteorological
> Magazine in December 1998 and was not published until March 2001 - a very
> long time lag between submission and publication, even for that journal.
> This contrasts with the eager fast-tracking that pro-warming papers
receive
> from the major journals.

Probably had the reviewers arguing if the paper had enough merit to be worth
publishing.


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Bio-Geo-Recon

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May 28, 2003, 12:07:46 PM5/28/03
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"Ian St. John" <ist...@spamcop.net> wrote in message
news:3ed4...@post.newsfeed.com...
<snip>

> > That effectively damns all large and medium size cities
> > as credible places from which to detect the fractions of a degree
changes
> > needed for detection of genuine climate change.
>
> Here is where the bullshit starts. The urban heat island effect is well
> evaluated on a station by station basis and the effect removed before
> processing. Nor is the statement that it creates large error bars
supported
> by the facts.
>
> <snip>

I was wondering if you or someone else would be good enough to explain
just exactly how the effect is removed. Without the exactness of "The
Formula," which only addresses the maximum difference and not the daily
differences, it would seem that there is considerable opportunity for
subjectivity. I would imagine that as you observed, "...it needs adjustment
for local climate since heating and cooling needs are not that uniform.",
that differences such as latitude and average windiness would also effect
the Delta T.
Clyde Spencer

w...@bas.ac.uk

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May 28, 2003, 5:34:12 PM5/28/03
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Bio-Geo-Recon <b...@jps.net> wrote:
> I was wondering if you or someone else would be good enough to explain
>just exactly how the effect is removed.

Try:

http://www.grida.no/climate/ipcc_tar/wg1/052.htm#222

This provides references, but it also provides a discussion of
trends with/out UHI-prone stations removed.

-W.

--
William M Connolley | w...@bas.ac.uk | http://www.nerc-bas.ac.uk/icd/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!

Roger Coppock

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May 29, 2003, 1:04:41 AM5/29/03
to

I have seen three ways to find long term temperature data sets
without UHI. Starting from the most simple they are:

1) Use only Sea Surface Temperature data. There are no urban areas
in the sea. Global mean SST data follows the global mean land data
quite well. This fact alone sinks any claim that the Urban Heat
Islands are the source of the observed warming. One can SEA this
for one's self. Here is land data:
http://www.giss.nasa.gov/data/update/gistemp/GLB.Ts.txt
Here is land and ocean data:
http://www.giss.nasa.gov/data/update/gistemp/GLB.Ts+dSST.txt

2) Use the ground readings of balloons before they launch them.
Radiosondes can not be launched in urban areas because they are
hazards to aircraft. These data also show the same warming. see:
http://cdiac.esd.ornl.gov/trends/temp/angell/angell.html
"...the University of East Anglia data of Jones et al. (2001)
indicate a global surface warming of 0.17°C/decade during
1979-2001 compared to the surface warming of 0.15°C/decade
obtained from the 63-station network."

3) Statistically remove UHI from an existing data set, dropping
entire stations if one has to:
To quote http://www.giss.nasa.gov/data/update/gistemp/
"We modify the GHCN/USHCN data in two stages to get to the station
data on which all our tables, graphs, and maps are based: in stage
1 we try to combine at each location the time records of the various
sources; in stage 2 we adjust the non-rural stations in such a way
that their long term trend of annual means is as close as possible
to that of the mean of the neighboring rural stations. Non-rural
stations that cannot be adjusted are dropped."


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Ian St. John

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May 29, 2003, 3:22:29 AM5/29/03
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"Bio-Geo-Recon" <b...@jps.net> wrote in message
news:m95Ba.19480$rO.18...@newsread1.prod.itd.earthlink.net...

Some background on UHI effects can be found at
http://rsd.gsfc.nasa.gov/912/urban/background.htm which is a good general
guide.

First you have to classify urban and rural areas. This is sometimes done
with comparison with known rural areas to see a differential trend, and
isolation of the stations that are affected by UHI warming. Sometimes they
use lighting as an indicator of urbanisation as in
http://antwrp.gsfc.nasa.gov/apod/image/0208/earthlights02_dmsp_big.jpg

Even without the UHI effect ( which is just one source of bias ) comparisons
of stations are run to show those which are not consistent in temperatures
with nearby similar stations. For example, a change in siting or instrument
may make a step in the readings. These effects must be either corrected for
or the station eliminated and this includes the UHI affected stations.
Differences in the procedures are necessary between countries. Even a change
in the time of reading may introduce an error ( as with Canadian East Coast
stations which changed their times of readings. All of this is well known
and competently corrected as is shown by the fact that the global warming
trends do NOT have any correlation with the Urban areas ( shown by the map
above ) when displayed as anomolies as at
http://www.giss.nasa.gov/data/update/gistemp/maps/ ( make your own )

More detailed descriptions of at least one climate database can be found at
http://lwf.ncdc.noaa.gov/oa/climate/research/ushcn/ushcn.html#QUAL which
references the procedures used for correcting for UHI in the paper Karl,
"T.R., H.F. Diaz, and G. Kukla, 1988: Urbanization: its detection and effect
in the United States climate record, J. Climate, 1, 1099-1123. "

Greenhouse

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May 29, 2003, 9:32:23 PM5/29/03
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<w...@bas.ac.uk> wrote

> Bio-Geo-Recon <b...@jps.net> wrote:
> > I was wondering if you or someone else would be good enough to
explain
> >just exactly how the effect is removed.
>
> Try:
>
> http://www.grida.no/climate/ipcc_tar/wg1/052.htm#222
>
> This provides references, but it also provides a discussion of
> trends with/out UHI-prone stations removed.

Thank you for the link. From that site:
"Thus we have assumed an uncertainty of zero in global land-surface air
temperature in 1900 due to urbanisation, linearly increasing to 0.06°C (two
standard deviations 0.12°C) in 2000."

This provides a rationalization but it is not convincing. Interpretations of
data may differ.

The Antarctic is maximally distant from urban influence. If global warming
or cooling (as opposed to local effects) has any reality apart from the
urban heat island effect, then the Antarctic is the place to detect the
phenomenon. The Antarctic is cooling. Occam's razor is a principle of logic
that predates the notorious "Precautionary Principle". Occam's razor states
that the simplest explanation is always most likely to be correct. The
simplest consistent explanation is that we do not have "global warming",
rather we have global cooling superposed on the Urban Heat Island effect.
Prove this interpretation wrong. And keep it simple. I'm serious about the
admonition to keep it simple. If you do not keep it simple, you violate the
logical principle of Occam's razor. One of the reasons for the all the venom
here is that we cannot agree even on the principles of logic to use.

Go ahead, disprove this simple interpretation in 100 words or less. If you
cannot do that you stand condemned as a climate modeler who lives in a
virtual world.


Thomas Palm

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May 30, 2003, 2:43:05 AM5/30/03
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Greenhouse wrote:
> The Antarctic is maximally distant from urban influence. If global warming
> or cooling (as opposed to local effects) has any reality apart from the
> urban heat island effect, then the Antarctic is the place to detect the
> phenomenon.

Not necessarily. There is no reason to assume all parts of the globe
should warm by the same amount, and since Antarctica is the continent
we have least knowledge about it really isn't a good place to use as a
test.

It is interesting, though, how greenhouse sceptics have retreated to
more and more distant places for their "evidence". Sort of like how
the place where the Gods lives moved away from forests, into a high
mountain and then up inte the sky and beyond as people learned more
about the world and where they weren't to be found.

> The Antarctic is cooling.

No, it isn't. This has been explained in this group plenty of
times.

> Occam's razor is a principle of logic
> that predates the notorious "Precautionary Principle". Occam's razor states
> that the simplest explanation is always most likely to be correct. The
> simplest consistent explanation is that we do not have "global warming",
> rather we have global cooling superposed on the Urban Heat Island effect.
> Prove this interpretation wrong.

Satellites show warming, boreholes show warming, the rising sea
levels indicate warming, melting glaciers all around the world
indicate warming etc. All not affected by UHI.

To save your "interpretation" you will have to add so many exceptions
and twists that it will certainly not be simple any more.

> And keep it simple. I'm serious about the
> admonition to keep it simple. If you do not keep it simple, you violate the
> logical principle of Occam's razor. One of the reasons for the all the venom
> here is that we cannot agree even on the principles of logic to use.
> Go ahead, disprove this simple interpretation in 100 words or less. If you
> cannot do that you stand condemned as a climate modeler who lives in a
> virtual world.

You want Occam's razor, OK let's give you Occam's razor:
Ever since Arrhenius first calculations over 100 years ago it has been
known that more CO2 ought to cause warming. These calculations have
become more refined as knowledge in physics increase. At the same time
we observe that CO2 levels increases and that the global temperature
increases. Now, what is the simplest exmplanation for all of this do
think? That the theories are correct and that CO2 does cause warming, or
that there are some unknown errors in the theories at the same time
as there are some unknown errors in all different ways of measuring
the global temperature?

Greenhouse

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May 30, 2003, 3:12:56 AM5/30/03
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Thomas you regurgitate the ideology very well.

"Thomas Palm" <thoma...@chello.se> wrote in message
news:3ED6FD79...@chello.se...

Thomas Palm

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May 30, 2003, 3:31:48 AM5/30/03
to
Greenhouse wrote:
>
> Thomas you regurgitate the ideology very well.

No I "regurgitate" tha science, but thanks for telling me I do
it well. Unlike some of the others here I'm not professionally
into climate science.

I'm afraid can't reciprocate. You can't even regurgitate the
contrarian ideological position very well.

Greenhouse

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May 30, 2003, 3:32:54 AM5/30/03
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"Thomas Palm" <thoma...@chello.se> wrote

> I'm afraid can't reciprocate. You can't even regurgitate the
> contrarian ideological position very well.

No, I'm helping to define it.


w...@bas.ac.uk

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May 30, 2003, 4:57:44 AM5/30/03
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Thomas Palm <thoma...@chello.se> wrote:
>Greenhouse wrote:
>> The Antarctic is maximally distant from urban influence. If global warming
>> or cooling (as opposed to local effects) has any reality apart from the
>> urban heat island effect, then the Antarctic is the place to detect the
>> phenomenon.

>Not necessarily. There is no reason to assume all parts of the globe
>should warm by the same amount, and since Antarctica is the continent
>we have least knowledge about it really isn't a good place to use as a
>test.

And there is the obvious fact that the oceans don't suffer from UHI and
show much the same warming. Plus of course the Antarctic records are all
fairly short - since 1957-ish - except for, I think, Orcadas which goes
back to 1900's. And shows... warming.

-W.

--
William M Connolley | w...@bas.ac.uk | http://www.antarctica.ac.uk/met/wmc/

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