Judith Curry has co-authored a new paper published in PNAS titled “Accelerated warming of the Southern Ocean and its impacts on the hydrological cycle and sea ice”. You can read a copy at her website.
Hat tip to SteveF over at Rabett Run.
I obtained a copy of it (yeah I paid $10) and have read it through. Well, to be honest, I’ve spent the last few hours trying to work through it. While I’m interested in the study itself and what it finds about this question, I’m really more interested in the treatment of Curry and her paper by the denialist/ skeptic/ contrarian crowd. I’ve been watching the response on WTFIUWT and wow. Just wow.
More on that later.
As to the paper, it reviews and addresses the “the seeming paradox of the observed increasing total Antarctic sea ice area for the past three decades” and presents the results of model runs using two of the IPCC scenarios for anthropogenic forcings.
One of the big debates in climate blog land is over the ice. As Mosher once quipped, alarmists run to the ice when every they are challenged and I could respond that skeptics/denialists point to arctic sea ice extent when they likewise are challenged. Ice seems to be a real point of contention. So, Curry and her co-author attempt to address the fact that despite the increase in global temperature over the past decades, total antarctic sea ice has increased rather than decreased.
So, in a layman’s nutshell, and correct me if I’m wrong on this, the authors hypothesize that warming in the atmosphere (which, contrary to the yahoos at WTFIUWT, warms the oceans). leads to warmer oceans, which leads to increase in evaporation and increased moisture in the lower troposphere. This moisture is transported by the “meridional circulation” towards the pole where it falls as liquid precipitation in the high-latitudes of the Southern Ocean (rain, IOW). More fresh water results in a slowdown of the heat transport due to decreased salinity. I take it this is similar to the thermohaline circulation in the Atlantic and its affects on temps in the North Atlantic. Increased precipitation in higher latitudes leads to an increase in snow and ice. Increased snow and ice increases albedo, which enhances this process, etc. This is enough to overcome the warming seen elsewhere.
Is that accurate from what you know or have read?
That’s a bit of a knock to those who point to increased ice extent in the Antarctic as some kind of proof against anthropogenic global warming. How many times have I seen this pulled out in response to a pro-AGW post? Too many. I believe Skeptical Science has some good work on this.
Back to Curry. I’m not up on the statistical analysis used to evaluate SST records or the projections using models so I will leave it to those who are up on it to comment on that aspect. Suffice it to say that the models did not show the observed variability in SST in the 20th century.
I was interested in the apparent inability of the models to capture the variability in SST in the last half of the 20th century.
“…none of the models’ individual ensemble members have the dominant spaciotemporal SST variability found in the observations what was characterized by the broad-scale warming of the Southern Ocean.”
So the models appear unable to replicate the variability in observed SSTs when the anthropogenic forcings of the last 50 years of the 20th century are used. This admission is used by Curry’s detractors at WTFIUWT as we shall see further down in the post.
The authors conclude, based on their model runs:
“With increased loading of greenhouse gasses through the 21st century, the models suggest that there is an accelerated warming in the Southern Ocean. Moreover, there is a strong poleward expansion of warming from low to high emissions. As shown in Fig. 4B, SST under sea ice in the 2090s is a few tenths of a degree warmer than in the 2000s, and the warming could be as large as 1 – 1.5C in the ACC. THus, the pronounced warming in the Southern Ocean during the 21st century offsets and exceeds the cooling effect associated with the decrease of upward ocean heat transport as a result of the enhanced hydrological cycle. As the warming extends poleward, the circumpolar westerlies are projected to intensify and shift poleward due to increasing greenhouse gasses, coupled with the presence of the Antarctic ozone hole.”
As I say, I’m not competent to evaluate the methodologies used in this paper. I am interested in what others who are more adept have to say and what they conclude so I so look forward to reading comments and response to the paper here and elsewhere.
And please, if I’ve made glaring errors, please post and correct me. I won’t be insulted.
I’m a bit taken aback by the response at WUWT — I suppose there must be a lot of scientists and experts on sea ice, antarctic climate and ocean dynamics there because the commenters question the very basis of the paper and Curry’s ability to do this research.
What I am interested in is the way the paper is received on skeptic/denialist/contrarian blogs, for Judith Curry seems to have hitched her wagon to the skeptics, making quite strong and in some cases, quite defamatory statements on skeptic blogs about climate scientists and science bloggers.
She appears to be trying to reach out to skeptics/deniers/contrarians in order to, well, I don’t really understand her motives or agenda in doing so, and so I will leave it at that.
Let us just say that she is a polarizing figure in this whole matter. AGW supporters question her motives, and skeptics laud her willingness to consort with them and criticize climate science and climate scientists.
But their response to her recent paper is quite awe inspiring.Over at WTFIUWT, the slings and arrows are let fly:
Mike G expresses it clearly:
Ed Caryl says:
August 17, 2010 at 6:15 am
I learned one thing here. Ignore Judith Curry!
Good luck getting your paper accepted Dr. Curry. The establishment seems to have turned on you, as they do to anyone who stops drinking the kool air and worshiping at their altar, even if only temporarily.
Willard might find this amusing — both sides use the reference to drinking kool aid. I’ve seen it used on both skeptic and supporter blogs so it’s a popular reference and carries a strong sense of ridicule.
Here’s a few responses to Curry’s paper that I noted:
The trick is to tag-team with the other authors to avoid blatant self-contradiction; and to almost-say or almost-imply with cunning shifts whereby a speculation or assumption is deftly transformed to a fact-base for further speculations and assumptions.
When all else fails, there’s the princess routine: that lofty and wistful yearning for a “thoughtful question”.
This paper is a big disappointment. I expected a little better from you. Another paper submitted with the aid of cronyism.
Wow reality trumping fiction as snowing in antarctica is now considered a paradox.
Wonder what they calla an normal warm day in sahara, a freak of nature?
We don’t want to hold you to this rock solid, scientifically based prognostication, Ms Curry. Science is supposed to be about SOLID predictions. Curry can’t even say unequivocally that SOME DAY the ice extent might actually start to shrink. Something as certain as the Sun coming up tomorrow, and she is waffling on it.
The problem is that she knows she is just flapping her gums. The reporters seemed not to notice and duly wrote it down
George E. Smith:
WHAT PARADOX ??
Gaiaa doesn’t make paradoxes; she takes care to see that everything works exactly as it is supposed to; so for the last time; there is no Antarctic paradox !
If you guys (and gals) don’t know how or why it works, why don’t you say so; instead of implying that you do understand how it works; but it isn’t working that way. You and your blathering are the paradox; not Antarctica !
And this is what passes for science in the 21st Century! . . . It’s overloaded with unjustifiable assumptions and speculative in the most obvious and shallow fashion conceivable.
So that amount of GHG forcing is baked in the cake as an assumption
because the 1d models lack fidelity to the real world where additional
CO2 cools the Earth/Atm system under some cases.
Empirical scientists would like to know.
BTW: Not missing a tropospheric hot spot are you, or some Long Wave radiation as measured by the ERBE and CERES satellites, and how are those model projections holding up vs the actual temperature record? Hmmmm?
In all seriousness – how on earth do I distinguish your all warming all cooling CO2 theory as an actual falsifiable scientific theory and not quakery?
As I said – please rule some phenomena out – then we can measure it and see how your theory stacks up. – anything else is nonsense.
Robert of Ottawa:
mosomoso says August 16, 2010 at 9:40 pm
…that the woman is shifty!
It may be that Judith Curry just doesn’t buy this BS any more, but cannot say that without losing her job. She is already on warning, I expect, given the reaction of the Team to her previous attempts at reason.
Judith is waving her arms about her so much she’s actually taken flight.
These folks at Georgia have no clue how Climate works. As the globe warms the precipitable potential arriving to the poles decreases; the perturbations that turn that potential into precipitation become weaker. And as usual, no mention of the upward migration of the rain/snow threshold in a warming scenario.
The media and these unscrupulous “scientists” try to deceive the public day by day with things like this. When will it all end?
These simpletons try to find false answers, to keep their agendas from failing. It’s all due to the oceanic oscillations. Yes, the Antarctic sea ice will melt in the next 30 years, but Arctic ice will increase. That’s why Antarctic Sea Ice hit a record low in 1980, and the Arctic hit a record high in 1980…………Antarctic temperature records, showed that it warmed very substantially from 1950-1977 (the cold PDO) then began to cool after that, solidifying my claim.
There’s much more, but I’ll end with this:
The propensity to speculate about the future and to see “signs” is endemic in science today. Increasingly, modern science is no longer distinguishable from voodoo or witchcraft. I suspect Judith and her cronies have a cauldron:
“Wool of bat and tongue of dog, Adder’s fork and blind-worm’s sting, Lizard’s leg and owlet’s wing, For a charm of powerful trouble, Like a hell-broth boil and bubble. ALL. Double, double toil and trouble; Fire burn and cauldron bubble.”
We skeptics can have oracles too – for McIntyre said that:
“Mann shall never vanquish’d be until
Great Burn’em wood to high Hokey shtick
Shall come against him.”
Curry has spent a great deal of time consorting with the skeptics and contrarians, but if she thought it would help prop up their view of climate science and her in particular, she was obviously wrong.