The latest satellite data establishes that the North Atlantic Current (also called the North Atlantic Drift) no longer exists

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Eric Swanson

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Oct 27, 2010, 5:05:23 AM10/27/10
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There's a claim making it's way around the internet that the Gulf
Stream has slowed. The proposed cause is the impact of the BP oil
spill in the Gulf of Mexico. Here's a link to a blog with the earliest
post I found with a brief Google search, first dated 29 Aug 2010:

http://europebusines.blogspot.com/2010/08/special-post-life-on-this-earth-just.html

The Gulf Stream is a wind driven Western Boundary Current. I saw no
discussion of this as the cause of the flow, only various conjectures
about the impact of the chemicals used to disperse the oil from the
blown out BP well. I think this claim is not supported by the facts
and the spreading of this idea only adds to the confusion in the
public mind regarding climate change.

Of course, the Gulf Stream isn't the THC. While changes in the THC
sinking in the Nordic and Labrador Seas might impact the path of the
waters derived from the warm Gulf Stream, such as the North Atlantic
Drift Current, that would not imply a shutdown of the basic wind
driven flow. There's no apparent link offered which can explain a
relationship between the oil spilled in the Gulf of Mexico and the
strength of the THC. That said, I think it is possible that the THC
has weakened, but the cause would most likely be the reported
freshening of the Nordic Seas which has occurred over the past few
decades. I've noted data from satellite passive microwave data which
suggests that the slowdown may have started 3 winters ago. If so, we
may indeed experience another cold winter over portions of of the
NH.

The weather is already getting interesting, with a massive storm
moving out of the Pacific over the US northern plains and Canada with
record low pressures recorded within. This lowest pressure measured,
around 28.20" (955 mb), is comparable to the low pressure seen within
a Cat 3 hurricane.

http://www.accuweather.com/blogs/news/story/40673/midwest-storm-breaks-us-pressu.asp

E. S.
---

Alastair

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Oct 27, 2010, 6:03:05 AM10/27/10
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On Oct 27, 9:05 am, Eric Swanson <e_swan...@skybest.com> wrote:
> There's a claim making it's way around the internet that the Gulf
> Stream has slowed.  The proposed cause is the impact of the BP oil
> spill in the Gulf of Mexico. Here's a link to a blog with the earliest
> post I found with a brief Google search, first dated 29 Aug 2010:
>
> http://europebusines.blogspot.com/2010/08/special-post-life-on-this-e...
>
> The Gulf Stream is a wind driven Western Boundary Current.  I saw no
> discussion of this as the cause of the flow, only various conjectures
> about the impact of the chemicals used to disperse the oil from the
> blown out BP well.   I think this claim is not supported by the facts
> and the spreading of this idea only adds to the confusion in the
> public mind regarding climate change.
>
> Of course, the Gulf Stream isn't the THC.  While changes in the THC
> sinking in the Nordic and Labrador Seas might impact the path of the
> waters derived from the warm Gulf Stream, such as the North Atlantic
> Drift Current, that would not imply a shutdown of the basic wind
> driven flow.  There's no apparent link offered which can explain a
> relationship between the oil spilled in the Gulf of Mexico and the
> strength of the THC.  That said, I think it is possible that the THC
> has weakened, but the cause would most likely be the reported
> freshening of the Nordic Seas which has occurred over the past few
> decades.  I've noted data from satellite passive microwave data which
> suggests that the slowdown may have started 3 winters ago.  If so, we
> may indeed experience another cold winter over portions of of the
> NH.
>
> The weather is already getting interesting, with a massive storm
> moving out of the Pacific over the US northern plains and Canada with
> record low pressures recorded within.  This lowest pressure measured,
> around 28.20" (955 mb), is comparable to the low pressure seen within
> a Cat 3 hurricane.
>
> http://www.accuweather.com/blogs/news/story/40673/midwest-storm-break...
>
> E. S.
> ---

The Morth Atlantic leg of the THC. or MOC (meridional overturning
circulation), is being monitored by the National Oceanography Centre
at Southampton University at great expense to British taxpayers.
http://www.noc.soton.ac.uk/rapid/rw/
AFAIAA they have not reported any RECENT slowing, although it is
possible that they are reticent to report what might be a second false
alarm.
http://en.wikipedia.org/wiki/Shutdown_of_thermohaline_circulation#Bryden_measurements_reported_late_2005

Cheers, Alastair.

Eric Swanson

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Oct 27, 2010, 11:06:12 AM10/27/10
to globalchange
So, Alastair, I take it you agree that there is no basis for the claim
that the BP oil spill in the Gulf of Mexico has caused a reduction in
the Gulf Stream and the THC. Of course, there is more to it. Notice
this quote from the Wiki article to which you linked:

"In January 2010, the Gulf Stream briefly connected with the West
Greenland Current after fluctuating for a few weeks due to an extreme
negative phase of the Arctic oscillation, temporarily diverting it
west of Greenland."

I suppose you folks in Britain has an enjoyable winter last year. I
saw a nice photographic composite showing the home isles covered with
snow. The folks in southern Greenland had record high temperatures
while you guys were freezing your butts. How many more such winters
would be required to convince folks that the Earth's climate is
changing? Just yesterday, the US experienced a storm with the lowest
reported surface pressure over an inland area. No worries, bro, it's
just another cycle in the weather...

E. S.
---------------------------------------------------
On Oct 27, 6:03 am, Alastair <a...@abmcdonald.freeserve.co.uk> wrote:
> On Oct 27, 9:05 am, Eric Swanson <e_swan...@skybest.com> wrote:
[cut]
>
> The Morth Atlantic leg of the THC. or MOC (meridional overturning
> circulation), is being monitored by the National Oceanography Centre
> at Southampton University at great expense to British taxpayers.http://www.noc.soton.ac.uk/rapid/rw/
> AFAIAA they have not reported any RECENT slowing, although it is
> possible that they are reticent to report what might be a second false
> alarm.http://en.wikipedia.org/wiki/Shutdown_of_thermohaline_circulation#Bry...
>
> Cheers, Alastair.

Alastair

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Oct 28, 2010, 6:26:16 AM10/28/10
to globalchange


On Oct 27, 3:06 pm, Eric Swanson <e_swan...@skybest.com> wrote:
> So, Alastair, I take it you agree that there is no basis for the claim
> that the BP oil spill in the Gulf of Mexico has caused a reduction in
> the Gulf Stream and the THC.  Of course, there is more to it.  Notice
> this quote from the Wiki article to which you linked:
>
> "In January 2010, the Gulf Stream briefly connected with the West
> Greenland Current after fluctuating for a few weeks due to an extreme
> negative phase of the Arctic oscillation, temporarily diverting it
> west of Greenland."

As I recall there was a cold anomaly in SSTs south of Greenland last
winter. We in the UK had a cold winter with more snow than in recent
times. I put that down to the cold SST anomally, and the unusual solar
minimum. I blamed global warming for the heavier snow, since it would
have resulted a more moist atmosphere.


> I suppose you folks in Britain has an enjoyable winter last year.  I
> saw a nice photographic composite showing the home isles covered with
> snow.  The folks in southern Greenland had record high temperatures
> while you guys were freezing your butts.  How many more such winters
> would be required to convince folks that the Earth's climate is
> changing?  Just yesterday, the US experienced a storm with the lowest
> reported surface pressure over an inland area.  No worries, bro, it's
> just another cycle in the weather...

We are all convinced that the climate is changing. Last winter's snow
was not unusual on a longer timescale, and we are suffering from more
flooding. The problem here is that not everyone is convinced that the
global warming is man made, and that is due to the propaganda pouring
out of the US, although the worst culprit is the owner of the London
Times and Sky TV (the main/only competitor to the BBC), the Aussie
Rupert Murdoch.

But with the Tea Party dominating the politics of the most powerful
nation in the world, I can only repeat what I have been saying all
along. We're all doomed!

Cheers, Alastair.

Tom Adams

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Nov 1, 2010, 3:33:42 PM11/1/10
to globalchange
It's becoming fashionable among deniers to attribute climate change
to natural causes like continued interglacial warming, rather than
to outright deny climate change. So, record warming, etc. will not
convince them. I am not sure there is anyone left to be convinced
by mere evidence of climate change predicted by climate scientist.
The remaining deniers may all be going to this new approach to denial.
> > Cheers, Alastair.- Hide quoted text -
>
> - Show quoted text -

Robert I Ellison

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Nov 7, 2010, 12:29:53 AM11/7/10
to globalchange
Is this a new approach? People have been saying for many years that
the climate record is characterised by change - indeed by abrupt
change - rather than stability. What record warming? 2010 is in
striking distance of 1998 and rapidly cooling - it seems doubtful that
there will be any statistically significant difference. The monthly
peak is clearly and emphatically still in early 1998 -ENSO related
warming.

Until natural variability is understood - particularly the connection
of ENSO and clouds in decadal timescales (see for instance
http://cat.inist.fr/?aModele=afficheN&cpsidt=19136615) there is little
prospect of understanding anthropogenic climate risk.

Mere evidence by scientists? This is one I have just read on decadal
surface solar variability - http://www.leif.org/EOS/2008JD011470.pdf.
And if you have a look at both the ISCCP-FD and ERBE SW(up) datasets -
there is clearly a decrease in reflected SW (less cloud) from the
1980's to the 1990's.

You are holding fast to ideas that are 100 years old. It seems very
much like new information doesn't challenge these ideas at all - it
seems very much like cognitive dissonance.
> > - Show quoted text -- Hide quoted text -

Eric Swanson

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Nov 7, 2010, 11:15:43 AM11/7/10
to globalchange
Your comment about Wild's commentary report in the JGR is short but
not sweet. The reference to the ERBE data is to an article in the AGU
newspaper, EOS, which is not archived on the AGU site before 2003.
Thus, one can not go back and read the article without treking into
some musty university library that might still have real books on the
shelf.

That said, I happen to have spent time looking at the ERBE scanner
data from the late 1980's. The wide field scanner suffers a basic flaw
in that it can not intercept radiation with an entrance angle outside
it's field of view. This is a particularly important problem over the
polar regions, where the reflection of SW from sunlight is strongly
dependent on the angle of incidence and thus a significant fraction of
the energy wasn't measured. I wrote a paper at the time in which I
pointed out this problem.

Your reference also notes that there is some disagreement regarding
the accuracy of the ISCCP data, noting:

"For example, the substantial decadal changes in the extended
cloud cover records from ISCCP, used as input in all above mentioned
satellite-derived SSR products, are controversial and may be spurious,
presumably owing to changes in the satellite viewing angles"

If you expect to be believed, you better go back and dig much deeper
into the data...

E. S.
------------------------------------------------------------------

Robert I Ellison

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Nov 7, 2010, 7:30:37 PM11/7/10
to globalchange
Eric,

I am not sure whose ERBE data reference you are talking about. The
ERBE data is graphed and discussed in AR4 - section 3.4.3 from
memory. The ISCCP data and a reasonably detailed dicussion of errrors
and problems is found at - http://isccp.giss.nasa.gov/projects/browse_fc.html

Wild simply discusses decadal changes in surface insolation -
brightening and dimming. The ISCCP record is discussed along with DTR
and surface SSR records predominantly.

I was simply talking about climate variability - which is evident in
any of the records and at any timescale. I can't help it of you have
foolishly been hoisted on your own petard with a false assumption of
climate stability.


Cheers
Robert
> > surface solar variability -http://www.leif.org/EOS/2008JD011470.pdf.
> > And if you have a look at both the ISCCP-FD and ERBE SW(up) datasets -
> > there is clearly a decrease in reflected SW (less cloud) from the
> > 1980's to the 1990's.
>
> > You are holding fast to ideas that are 100 years old.  It seems very
> > much like new information doesn't challenge these ideas at all - it
> > seems very much like cognitive dissonance.- Hide quoted text -

Eric Swanson

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Nov 7, 2010, 10:29:49 PM11/7/10
to globalchange
Robert, it was you who made reference to the data

"...And if you have a look at both the ISCCP-FD and ERBE SW(up)
datasets - there is clearly a decrease in reflected SW (less cloud)
from the 1980's to the 1990's..."

I just pointed out that there are problems with both sets, the ERBE
instrument being one which I studied. The IPCC AR4 reference to which
you pointed comments on the later ERBS data, concluding:

"In summary, while there is some consistency between ISCCP, ERBS,
SAGE II and surface observations of a reduction in high cloud cover
during the 1990s relative to the 1980s, there are substantial
uncertainties in decadal trends in all data sets and at present there
is no clear consensus on changes in total cloudiness over decadal time
scales...."

Yes, yet again, let me remind you that there is lots of evidence of
variation in climate. That knowledge is one of the reasons we address
"climate change" these days, not simply "global warming". However, I
do think it's important for mankind that our civilization has evolved
during the Holocene, which appears to be a warm period relative to the
norm over the past 3 million years or so. During the past 8000 years,
the variation in climate appears to have been rather minor, compared
to the climate of the Ice Ages. I do not assume that the future will
be a repeat of the warm conditions of the past 8 thousand years. If
climate were not influenced by mankind's activities, I think it's
clear that at some time in the future, Ice Age conditions would
return, continuing the long term pattern. I don't see how you can
conclude that I expect climate to be stable, as mankind is changing
the basic physics of the situation. After all, climate can be thought
of as the statistics of weather and that includes the statistics of
the longer variations as well.

E. S.
------------------------------------------------
On Nov 7, 7:30 pm, Robert I Ellison <rob...@robertellison.com.au>
wrote:
> Eric,
>
> I am not sure whose ERBE data reference you are talking about.  The
> ERBE data is graphed and discussed in AR4 - section 3.4.3 from
> memory.  The ISCCP data and a reasonably detailed dicussion of errrors
> and problems is found at -http://isccp.giss.nasa.gov/projects/browse_fc.html

Robert I Ellison

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Nov 10, 2010, 6:00:08 AM11/10/10
to globalchange

‘The time series of total and low-level cloud cover averaged over the
NE Pacific (115° to 145°W, 15° to 25°N) are displayed in Fig. 1, A and
B. Both COADS and adjusted ISCCP data sets show a shift toward more
total cloud cover in the late 1990s, and the shift is dominated by low-
level cloud cover in the adjusted ISCCP data (bars, in Fig. 1B). The
longer COADS total cloud time series indicates that a similar-
magnitude shift toward reduced cloud cover occurred in the mid-1970s,
and this earlier shift was also dominated by marine stratiform clouds
(bars, Fig. 1A).’

‘Our observational analysis indicates that increased SST and weaker
subtropical highs
(Fig. 4A) will act to reduce NE Pacific cloud cover…’

http://meteora.ucsd.edu/~jnorris/reprints/PacCloudFeedback.pdf

‘Tropical and subtropical low-level marine clouds consist of optically
thick stratocumulus clouds, which usually form over the regions
associated with relatively cold sea surface temperatures (SST) and the
atmospheric subsidence, and optically thin shallow cumuli in the
tradewind regime. These low-level clouds play a pivotal role in the
global climate system not only by affecting radiative budgets but also
by promoting heat and moisture exchange between the sea-surface, the
boundary layer, and the overlying troposphere.’

Ping, Z., Hack, J., Keilh, J and Zhu, P, Bretherton, C. 2007, Climate
sensitivity of tropical and subtropical marine low cloud amount to
ENSO and global warming due to doubled CO2 - JGR, VOL. 112, 2007)

‘One important development since the TAR is the apparent unexpectedly
large changes in tropical mean radiation flux reported by ERBS
(Wielicki et al., 2002a,b). It appears to be related in part to
changes in the nature of tropical clouds (Wielicki et al., 2002a),
based on the smaller changes in the clear-sky component of the
radiative fluxes (Wong et al., 2000; Allan and Slingo, 2002), and
appears to be statistically distinct from the spatial signals
associated with ENSO (Allan and Slingo, 2002; Chen et al., 2002). A
recent reanalysis of the ERBS active-cavity broadband data corrects
for a 20 km change in satellite altitude between 1985 and 1999 and
changes in the SW filter dome (Wong et al., 2006). Based upon the
revised (Edition 3_Rev1) ERBS record (Figure 3.23), outgoing LW
radiation over the tropics appears to have increased by about 0.7 W m–
2 while the reflected SW radiation decreased by roughly 2.1 W m–2 from
the 1980s to 1990s (Table 3.5).

'The most accurate of the data sets in Table 3.5 is believed to be the
ERBS Edition 3 Rev 1 active-cavity wide field of view data (Wielicki
et al., 2005). The ERBS stability is estimated as better than 0.5 W m–
2 over the 1985 to 1999 period and the spatial and temporal sampling
noise is less than 0.5 W m–2 on annual time scales (Wong et al.,
2006). The outgoing LW radiation changes from ERBS are similar to the
decadal changes in the HIRS Pathfinder and ISCCP FD records, but
disagree with the AVHRR Pathfinder data (Wong et al., 2006). The AVHRR
Pathfinder data also do not support the TOA SW radiation trends.
However, calibration issues, conversion from narrow to broadband, and
satellite orbit changes are thought to render the AVHRR record less
reliable for decadal changes compared to ERBS (Wong et al., 2006).
Estimates of the stability of the ISCCP time series for long-term TOA
flux records are 3 to 5 W m–2 for SW radiative flux and 1 to 2 W m–2
for LW radiative flux (Brest et al., 1997), although the time series
agreement of the ISCCP and ERBS records are much closer than these
estimated calibration drift uncertainties (Zhang et al., 2004c).'

‘As noted in Section 3.4.3, the low-latitude changes in the radiation
budget appear consistent with reduced cloud fraction from ISCCP.
Detailed radiative transfer computations, using ISCCP cloud products
along with additional global data sets, show broad agreement with the
ERBS record of tropical radiative fluxes (Hatzianastassiou et al.,
2004; Zhang et al., 2004c; Wong et al., 2006). However, the decrease
in reflected SW radiation from the 1980s to the 1990s may be
inconsistent with the increase in total and low cloud cover over
oceans reported by surface observations (Norris, 2005a), which show
increased low cloud occurrence. The degree of inconsistency, however,
is difficult to ascertain without information on possible changes in
low-level cloud albedo.’

My note here is that there is a consensus on why cloud cover is
influenced by SST - and the biggest factor in variable sea surface
temperature is ENSO.

'In summary, although there is independent evidence for decadal
changes in TOA radiative fluxes over the last two decades, the
evidence is equivocal. Changes in the planetary and tropical TOA
radiative fluxes are consistent with independent global ocean heat-
storage data, and are expected to be dominated by changes in cloud
radiative forcing. To the extent that they are real, they may simply
reflect natural low-frequency variability of the climate system.'

http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch3s3-4-4-1.html

Really - just picking a paragraph on some supposed inconsistency of
satellite and surface observations is BS. Anything that doesn't fit
the preconceived notions isn't real?

Cheers
Robert
> > Robert- Hide quoted text -

Eric Swanson

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Nov 10, 2010, 8:24:58 AM11/10/10
to globalchange
Robert, I responded to your reference. In your comment, you ignored
the caveat at the end of the quoted section. I was not "picking a
paragraph", but was pointing out the conclusions of the authors of
that section of the AR4. Are you suggesting that the authors of the
section you quoted were actually wrong and were are issuing BS? If
you think those conclusions were actually BS, why did you cherry pick
the section for a reference?

Besides, you muffed the reference to the satellite analysis. Here it
is for those interested:

P. Zhu, J. J. Hack, J. T. Kiehl, and C. S. Bretherton, Climate
sensitivity of tropical and subtropical marine low cloud amount to
ENSO and global warming due to doubled CO2, J. Geophys. Res., 112,
D17108, doi:10.1029/2006JD008174, 2007

I was also responding to your assertion that I think climate isn't
variable, which I clearly do not.

E. S.
-------------------------------------------------------------------------------------------

Robert I Ellison

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Nov 11, 2010, 5:32:09 PM11/11/10
to globalchange
The reporting of the data is correct. The finding that it is not
consistent with surface observation of clouds is not supported by
either theory - as in the Ping Zhu reference (not satellites but
models of cloud formation in relation to SST - which I don't think I
'muffed') or in COAD observations in the northeast Pacific (one of the
most important areas for these observations) by Amy Clements and
colleagues. A decadal cloud/sst relationship. Warm SST = less low
level cloud and vice versa.



On Nov 10, 11:24 pm, Eric Swanson <e_swan...@skybest.com> wrote:
> Robert, I responded to your reference.  In your comment, you ignored
> the caveat at the end of the quoted section.  I was not "picking a
> paragraph", but was pointing out the conclusions of the authors of
> section you quoted were actually wrong and were are issuing BS?  If
> you think those conclusions were actually BS, why did you cherry pick
> the section for a reference?
>
> Besides, you muffed the reference to the satellite analysis.  Here it
> is for those interested:
>
> P. Zhu, J. J. Hack, J. T. Kiehl, and C. S. Bretherton, Climate
> sensitivity of tropical and subtropical marine low cloud amount to
> ENSO and global warming due to doubled CO2, J. Geophys. Res., 112,
> D17108, doi:10.1029/2006JD008174, 2007
>
> I was also responding to your assertion that I think climate isn't
> variable, which I clearly do not.
>
> E. S.
> ---------------------------------------------------------------------------­----------------
>
>
>
> Robert I Ellison wrote:
>
> > My note here is that there is a consensus on why cloud cover is
> > influenced by SST - and the biggest factor in variable sea surface
> > temperature is ENSO.
>
> > 'In summary, although there is independent evidence for decadal
> > changes in TOA radiative fluxes over the last two decades, the
> > evidence is equivocal. Changes in the planetary and tropical TOA
> > radiative fluxes are consistent with independent global ocean heat-
> > storage data, and are expected to be dominated by changes in cloud
> > radiative forcing. To the extent that they are real, they may simply
> > reflect natural low-frequency variability of the climate system.'
>
> >http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch3s3-4-4-1.html
>
> > Really - just picking a paragraph on some supposed inconsistency of
> > satellite and  surface observations is BS.  Anything that doesn't fit
> > the preconceived notions isn't real?
>
> > Cheers
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