UPDATE: 8/18 10:30AM I spoke with Dr. Judith Curry by telephone today, and she graciously offered the link to the full paper here, and has added this graphic to help clarify the discussion. I have reformatted it to fit this presentation format (side by side rather than top-bottom) While this is a controversial issue, I ask you please treat Dr. Curry with respect in discussions since she is bending over backwards to be accommodating. – Anthony
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[Update] My thanks to Dr. Curry for showing the graphic above, as well as for her comment below and her general honesty and willingness to engage on these and other issues. She should be a role model for AGW supporters. I agree totally with Anthony’s call for respect and politeness in our dealings with her (as well as with all other honest scientists who are brave enough to debate their ideas in the blogosphere). I also commend the other author of the study, Jiping Liu, for his comments below.
However, as my Figure 2 below clearly shows, any analysis of the HadISST data going back to 1950 is meaningless for the higher Southern latitudes. The HadISST data before about 1980 is nonexistent or badly corrupted for all latitude bands from 40°S to 70°S. As a result, although the HAdISST graphic above looks authoritative, it is just a pretty picture. There are five decades in the study (1950-1999). The first three of the decades contain badly corrupted or nonexistent data. You can’t make claims about overall trends and present authoritative looking graphics when the first three-fifths of your data is missing or useless. – willis
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Guest Post by Willis Eschenbach
Anthony has posted here on a new paper co-authored by Judith Curry of Georgia Tech, entitled “Accelerated warming of the Southern Ocean and its impacts on the hydrological cycle and sea ice”. The Georgia Tech press release is here. Having obtained the paper courtesy of my undersea conduit (h/t to WS once again), I can now comment on the study. My first comment is, “show us the data”. Instead of data, here’s what they start with:
Kinda looks like temperature data, doesn’t it? But it is not. It is the first Empirical Orthogonal Function of the temperature data … the original caption from the paper says:
Figure 1. Spatial patterns of the first EOF mode of the area-weighted annual mean SST south of 40 °S. Observations: (A) HadISST and (B) ERSST for the period 1950–1999. Simulations of CCSM3 (Left) and GFDL-CM2.1 (Right): (C, D) 50-year PIcntrl experiment (natural forcing only),
Given the title of “Accelerated warming”, one would be forgiven for assuming that (A) represents an actual measurement of a warming Southern Ocean. I mean, most of (A) is in colors of pink, orange, or red. What’s not to like?
When I look at something like this, I first look at the data itself. Not the first EOF. The data. The paper says they are using the Hadley Centre Sea Ice and Sea Surface Temperature (HadISST) data. Here’s what that data looks like, by 5° latitude band:
Figure 2. HadISST temperature record for the Southern Ocean, by 5° latitude band. Data Source.
My first conclusion after looking at that data is that it is mostly useless prior to about 1978. Before that, the data simply doesn’t exist in much of the Southern Ocean, it has just been shown as a single representative value.
So if I had been a referee on the paper my first question would be, why do the authors think that any analysis based on that HadISST data from 1950 to 1999 has any meaning at all?
Next, where is the advertised “Accelerated warming of the Southern Ocean”? If we look at the period from 1978 onwards (the only time period with reasonable data over the entire Southern Ocean), there is a slight cooling trend nearest Antarctica, and no trend in the rest of the Southern Ocean. In other words, no warming, accelerated or otherwise.
Finally, I haven’t even touched on the other part of the equation, the precipitation. If you think temperature data is lacking over the Southern Ocean, precipitation data is much worse. The various satellite products (TRMM, SSM/i, GPCC) give widely varying numbers for precipitation in that region, with no significant correlation between any pair (maximum pairwise r^2 is 0.06).
My conclusion? There is nowhere near enough Southern Ocean data on either side of the temperature/precipitation equation to draw any conclusions. In particular, we can say nothing about the period pre-1978, and various precipitation datasets are very contradictory after 1978. Garbage in, you know what comes out …
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Willis, the “accelerated warming” does not refer specifically to observations in the 20th century. Yes, there is warming in the mid latitudes based upon the data we have available to us. The accelerated warming refers to how our hypothesis regarding antarctic sea ice, the hydrological cycle, and upper ocean temperatures responds in a warmer climate scenario.
Pamela Gray, thank you for pointing out the paper by Marika Holland, this is one I haven’t read. In commenting on this one I have to declare my bias: I was Marika Holland’s Ph.D. advisor at the University of Colorado in the 1990’s. I think that she does terrific work.
Steven Wilde, I am not exactly sure what your question is. But the hydrological cycle relates surface evaporation, precipitation, and the storage of water in the atmosphere both as humidity (water vapor) and also cloud water (liquid and ice). Whereas some people talk about the acceleration of hydrological cycle globally, it makes more sense to me to talk about it regionally. As an example, look at the Sahel. It has undergone periods of drought and then relative abundance of rainfall. This reflects a different strength of the local hydrological cycle. In terms of the global hydrological cycle, as the atmosphere and ocean surfaces warm, the ocean can evaporate more water and atmosphere has the capacity to “hold” more water, even as the atmospheric relative humidity remains the same. The basic physics behind this is the Clausius-Clapeyron equation, based on the first and second laws of thermodynamics, that explains the saturation vapor pressure.
I certainly look forward to better data sets in the future. Because the models represent an internally consistent and complete set data (albeit not observations), the models were used to actually understand and test the physical mechanism. We selected the models that do the best job of simulating the Antarctic atmosphere and ocean circulations and the sea ice. Hence the physical mechanism does not depend on the detailed history of the observations of Antarctic sea ice. To further understand the mechanism, we looked at a warming scenario that the climate models had simulated. I agree that it would be very interesting to see what a cooling scenario would like like and how our mechanism would perform in such a scenario. There may be some paleoclimate simulations that would be interesting to consider in this regard.
Willis, I just finished my post on Liu and Curry:
http://bobtisdale.blogspot.com/2010/08/on-liu-and-curry-2010-accelerated.html
Regards
“If the data are bad and the model is wrong, that doesn’t falsify the hypothesis, it reduces the support for the hypothesis.”
So if, as you have stated elsewhere, you think the data are incomplete and methodology for constructing the data is not totally sound, why produce this paper and mention “accelerated warming”.
This is the exact reason why “sceptics” get upset. To me, releasing this paper is more about grants and politics than hypotheses.
Judith Curry writes:
“When precip falls on the open ocean, it doesn’t matter too much whether it is rain or snow (there is a small latent heat of melting the snow),”
A small latent heat? The latent heat of fusion of water is 144BTU/pound. That’s what’s required to turn a pound of water at 32F into a pound of ice at 32F. It is 144 times that required to raise the temperature of a pound of water by one degree. In other words if you put a half pound of ice at 32F into a half pound of liquid water at 176F you will end up with one pound of water at 32F.
tonyb asked: “So appreciating we are comparing apples with oranges can anyone give me some idea of just how many bits of actual verifiable data points have gone to make up the study which Willis is examining and how accurately that can depict a vast moving mass of a liquid which isn’t at all well mixed?”
ICOADS is the source data for the buoy- and ship-based readings used by Hadley and NCDC. The KNMI Climate Explorer…
http://climexp.knmi.nl/selectfield_obs.cgi?someone@somewhere
…gives the option of plotting the number of observations but I’m not sure about the units. The gentleman who runs the Climate Explorer is on vacation till the end of the month so I can’t verify it right now.
The other option would be to go directly to the ICOADS website—and—downloading the data—and—sorting through it.
http://www.esrl.noaa.gov/psd/data/gridded/data.coads.2deg.html
@rbateman says:
‘August 19, 2010 at 2:48 am
1DandyTroll says:
August 18, 2010 at 11:38 pm
Here is another paradox:
Find someone who does not wear sunglasses.
Ask them to describe how bright the sunlight is these days.’
I did, but now the doctor says I prolly need a new cornea. He said I was lucky it’s somewhat cloudy. I said really I can’t see no clouds? +_-
Bob Tisdale, just checked out your post, looks good. The reason we we considered the period 1950-1999 was to optimize the match between the period when the data has some credibility (1950-present) and the 20th century climate model simulations (1900-1999), hence the period 1950-1999 that was selected for our analysis.
This is a very interesting thread. The tone and tenure of the comments are very much appreciated.
I have been trying to reconcile the gap between claims that the Antartic is cooling and the title of Dr. Curry, et al, ‘s paper.
Then I have read and re-read (and read again), Dr. Curry’s last comment, to wit: “The accelerated warming refers to how our hypothesis regarding antarctic sea ice, the hydrological cycle, and upper ocean temperatures responds in a warmer climate scenario.”
I can’t fully interpret what she is saying, but it appears to me that what she means is that IF the Antartic WAS warming, then the Dr.s’ model provides a “prediction” of what would happen. Do I have this right??
It would be nice if Dr. Curry could provide further clarification on her statement or at the very least a reconciliation with the data showing that the Antartic is cooling.
Judith Curry says: August 18, 2010 at 12:26 pm
The 1940 period is very interesting. Globally there is a bump in surface temperatures that peaks in 1940 (land and oceans, both hemispheres). There have been attempts to explain this away by aerosol forcing, which is mostly a bogus argument IMO, particularly for the southern hemisphere.
Aerosol forcing is not a bogus argument at all. There were absolutely a very large amount of volcanic eruption volume in the 1930’s. Just take a look year by year. All the zones were producing radiation absorbing ash aerosols.
http://www.volcano.si.edu/world/find_eruptions.cfm
The thing is, these eruptions were not making it into the stratosphere. They were loading the troposphere with solar radiation absorbing aerosols that produce heat in the surrounding low atmosphere. Take a look.
http://en.m.wikipedia.org/wiki/Timetable_of_major_worldwide_volcanic_eruptions
Main article: Global dimming
The Global dimming through volcanism (ash aerosol and sulfur dioxide) is quite independent of the eruption VEI.[79][80][81] When sulfur dioxide (boiling point at standard state: -10°C) reacts with water vapor, it creates sulfate ions (the precursors to sulfuric acid), which are very reflective; ash aerosol on the other hand absorbs Ultraviolet.
http://www.pnas.org/content/101/17/6341.full
Evidence has been accumulating for decades that volcanic eruptions can perturb climate and possibly affect it on long timescales
Anthony, do you have that graph that shows volcanic aerosols levels in the stratosphere by the US Air Force and the solar cycles? I remember we were looking at it and you found it fascinating and were wanting to post it? It showed low levels in the stratosphere of the 1930’s and I wondered how, with such a high VEI volume. Was it Paul Vaughn that has it?
@tonyb
‘Land- unlike currents- doesn’t move or vary in thickness, ‘
Huh, actually land vary a lot, just more slowly, but it still changes pretty much every year, ‘specially in the northern hemisphere where land rise since the last ice age is still on going. Then you have erosion. Moving continents shelves. Sand shifting. Not to mention earth quakes that apparently can move the whole earth with the force to actually slow down our planets rotational speed as they say happened with the earth quake in Chile.
Oh my dear!, seriously, you have demostrated what we already knew: The 1997-98 big El Niño was the end of all that warming that gave all of you enough fuel to set on fire the whole world; however it ended precisely not in 1999 but a year before.
Now the business is over, then, back to the real world!
“Judith Curry says:
August 19, 2010 at 3:44 am
Willis, the “accelerated warming” does not refer specifically to observations in the 20th century. Yes, there is warming in the mid latitudes based upon the data we have available to us. The accelerated warming refers to how our hypothesis regarding antarctic sea ice, the hydrological cycle, and upper ocean temperatures responds in a warmer climate scenario.”
———————————————-
So the paper is an anlysis of the results of a number of model runs.
Also I am not impressed with the continual evasion of the main point. You simply *don’t* have the data.
Try running the model with post-1979 data only. I would be interested to see the result.
Also I think it is highly mis-leading to open the paper abstract with “The observed sea surface temperature (SST) in the Southern Ocean shows a substantial warming trend for the second half of the 20th century.”
Dr. Curry,
How do the observed Antarctic ice and Southern Sea SST anomalies for the decade since 1999 compare to your model predictions?
Seriously, one of the first emergency measures you americans should take in these economic troubled times is to cut from the root all spending in repetitive and silly research and projects not having an inmediate and high Internal Rate of Return and instead give all those resources back where they are always better applied: The common and hard working citizen.
@Willis
You wrote:
“so your hypothesis is explaining a problem that doesn’t exist …”
Yes but I think what Curry is trying to say is a yabbut situation.
Increasing sea over a cooling ocean doesn’t need any new explanation. What Curry is saying is “Yes, but… [yabbut] we have a hypothesis which can also explain growing sea ice over a warming ocean.”
So in effect we now have a theory of sea ice where:
o – sea ice can grow over an ocean that is warming
o – sea ice can grow over an ocean that is cooling
o – sea ice can shrink over an ocean that is warming
o – sea ice can shrink over an ocean that is cooling
This is a theory of sea ice that explains everything. In philosophy of science there’s an old saw (I think it’s a paraphrase of Karl Popper) that goes “a theory that explains everything explains nothing”.
The long and the short of it is that you can’t make any connection between sea ice extent (growth or shrinkage) and ocean cooling or warming because all combinations of growth/shrinkage/warming/cooling can happen.”
But I think most of us knew already that warmer water leads to a higher rate of evaporation which in turn leads to higher precipitation and if the precipitation is frozen and falling on a frozen surface it’s going to build ice from the surface upwards wherein the usual mechanism for ice formation on water is from the bottom downwards.
Submitted all on its own.
Bob Tisdale has done an analysis on his site and quite frankly Dr. Judith I’m very disappointed in what you have done here. It’s back to the bad old ways.
Quote, Judith Curry, ” the models represent an internally consistent and complete set data (albeit not observations)”
This is not science, this is semantics.
This paper represents an attempt to create something of value out of nothing. It is word long but essentially meaningless.
Curry writes:
“Snow in the high southern latitudes can fall on the open water, on sea ice, and on the glacier; its fate is different in each case. When it falls on water, it immediately melts.”
Not if the water is 32F (sea level standard atmosphere). In that case the snowflakes that land on it will not melt. As one commenter noted from personal observation it forms “slush” which is a mixture of water at 32F and ice at 32F.
Dr. Curry,
I appreciate your response, especially since I may not have been as clear as I wanted to be. I am still not sure that your hypothesis answers any question, whether regarding the current state of Antarctic sea ice or the future state.
To me you seem to be saying that in the current (no accelerated warming, in fact slightly cooling) Antarctic climate the summer sea ice melts almost completely, and the winter ice is getting bigger. And in the modelled accelerated warming climate the summer sea ice will also melt almost completely, and the winter sea ice will also get bigger. Perhaps there will be more melting in the summer, but there will also be more ice available to melt.
This is pasted from your paper:
“As a consequence, the reduced upward ocean heat flux and increased snowfall associated with the enhanced hydrological cycle tends to maintain the Antarctic sea ice, which is consistent with the seeming paradox of the observed increasing total Antarctic sea ice area for the past three decades…”
So, your mechanism explains the ice area for the past three decades, but it assumes a warming trend that does not exist in observations of the past three decades?
That might be what Larson desires but that’s not what the law has to say about it.
http://en.wikipedia.org/wiki/Fair_use
Fair use doctrine can be complicated but the gist of it is that:
Dr. Curry,
After re-reading the paper, I see that it suggests that the past three decades of cooling are the RESULT of the increased hydrologic cycle.
So the kicker is that the AGW signal will overwhelm this cooling in the future.
I apologize for my thickness, I think I understand the paper better, now. It is assumed that AGW caused the increase precip., which caused the recent cooling and increased sea ice. Therefore, AGW must continue to be the determinant factor for future Antarctic climate, despite the fact that the period of the study includes natural climate cycles that could have resulted in similar warming/cooling oscillations. This cooling blip is a temporary feature in an overall upward trend?
Hilarious! Thanks for the chuckle.
Building on the shoulders of giants I’m going to extend your hypothesis based upon Gregor Mendel’s work with inheritance in pea plants.
I hypothesize two dogs both hatched from sheep eggs. If these dogs breed and lay eggs one in four of those dog eggs will have a sheep in it.