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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Why is it that decreasing ice is global warming but increasing ice is a paradox. I suppose it makes sense if: A, facts should never be more believable than theory or models and B, You are determined to not believe your lying eyes.
I can’t make any sense of this without reading the full paper. It just does not look right as Willis had pointed out. I think it fair to say the EOF mode has some problems, not the lest of which is a lack of data. These models often look straight forward but like all these thing the devil is in the details. I think one needs to be paying very close attention to the currents in the area too. When you try and relate two different fluid dynamic systems, neither of which is fully understood, together the results can be anything but accurate.
Actually, there may be a rather simplistic behavior trait lying right in front of us, which explains the steadfast reluctance to stop falling headlong into yet another warming model:
Computer games are intensely addictive.
Check out the kids (even adults) …they can’t stop. Just one more bonus point, one more spell, one more data tweak, and I’ll be victorious.
Until the next game comes out.
chris1958 says:
August 17, 2010 at 10:11 pm
Then Dr. Curry should respond by showing a cooling model, and it’s hindcast/forecast.
The problem is, nobody wants to look at the other possibility, i.e. – global cooling causes cooling.
Reminds me way too much of the economic bubbles: so few were daring enough to challenge, so many were swept away in the frenzy of the day.
Where are the cooling models?
“It takes a big man to see and admit and correct his own mistakes, it seems that there is a dire shortage of big men in climate science today.”
And not only in Climate Science, it’s a freaking “Low T” epidemic!
I think it would be courteous to ask her first.
Responding to:
trbixler says:
August 17, 2010 at 8:34 pm
Judith has been more open minded than many others. But the underlying motive many have for defending AGW has most often seemed to be ideological, either political (collectivist/socialist/communist) or religious (~Pantheism) or both. But there are rent seekers as well. Missing is objectivity, critical to scientific discovery.
Willis, excellent summary of the paper. Can you comment on this study with regard to the following references?
Gille, 2002: Warming of the Southern Ocean Since the 1950s. Science, Vol. 295. no. 5558, pp. 1275 – 1277
Gille, 2008: Decadal-Scale Temperature Trends in the Southern Hemisphere Ocean. J. Climate, 21, 4749-4765
Jacobs, 2006: Observations of change in the Southern Ocean. Phil. Trans. R. Soc. A Vol. 364 no. 1844 1657-1681
Fyfe et al. 2007: The Role of Poleward-Intensifying Winds on Southern Ocean Warming. J. Climate, 20, 5391-5400
Gille 2008 is cited in the new paper you commented on; the others are not. The reason I’m asking is that I was under the impression that increasing wind speeds over the Southern Ocean were due to warming Southern Ocean SSTs (or at least there was a relationship between the two), but I’m not an expert, that’s just something I read.
I look forward to the mechanism that turns precipitation into sea ice.
Temperatures in Antarctica varies between -40 deg Celcius (hottest) to -70 deg Celcius.
Right? Or am I wrong on this?
So in order to get rain, one would need a temperature increase of at least 40 degrees?
I don’t understand.
Do they really expect 40 degrees increase in tempeature in Antarctic?
chris1958 says:
August 17, 2010 at 10:11 pm
I admire Judith greatly, for a variety of reasons including those you listed. I’ve got a lot of time for her in general.
However, as near as I can tell, in this case she is using garbage as the input to her 1950-1999 EOF calculations … what is your preferred circumlocution to describe that situation?
My advantage in this is my disadvantage, which is that I am a seaman with lots and lots and lots of time spent on the ocean. The Southern Ocean, particularly in the southerly parts, is one of the least visited parts of the planetary ocean. It scares us folks that go to sea. It is not on any mercantile route to anywhere. In the fifties and sixties it might have been visited by a couple of ships per year. So when I saw that Dr. Curry was analyzing the 1950-1999 time period, my bad number detector started ringing like mad. I thought “No way the data will allow that.”
So I took a look at the data, and sure enough, in the southern part of the Southern Ocean the “data” gives us the same temperature year in and year out from 1870 to 1940. Then there’s a half degree jump, and after that, again we get the same temperature year after year until the late seventies.
Now, it is possible that’s not “Garbage In” for the 1950’s and 60’s, but I’m a simple cowboy who addled his brain by going to sea in my youth, and I tend to call them as I see them. Or “sea” them, as it were …
So I truly do hope that Judith shows up and tells me exactly where I went off the rails. Wouldn’t be the first time that I’ve been very wrong.
But I’m not holding my breath.
I had hope for Curry, but this is just stupid. Both poles have gotten colder in the last 5 years. The Antarctic for the last 15, albeit very slowly. A mere degree F. It is true the ice extent in the Arctic has substantially decreased. But given the temperature, it means the decrease is caused by something other than warming…..like tides or wind. It is not like the outer ice is much to begin with.
They just had the NZ weather news tried to be broadcast from Scott Base Antarctica. The poor woman had to stop it was too cold.. somewhere around -36 with wind chill taking it to -55
RE: rain.
There is some confusion here about the rain. The paper isn’t proposing that it will rain at the South Pole, but that more rain will occur over Antarctic sea ice.
Dr Curry, bringing a climate vindaloo to a Southern Ocean data table near you.
:0/
Oakden Wolf says:
August 17, 2010 at 10:52 pm
Unfortunately, I don’t have time to do all of those. I looked at the first one. Same thing. In fact, worse, because these were mid-depth temperature readings from 700 to 1,100 metres, which were undoubtedly much less common than surface temperatures.
Their Figure 1 (b) shows the distribution of shipboard temperature profiles used in the study as a function of decade. A close examination of the figure shows 73 separate temperature profiles taken in the 1950s between sixty and seventy degrees south.
Now, think about that. We’re talking about a decade, and nineteen million square kilometres (seven million square miles) of ocean. That’s a huge area, extending out more than a thousand kilometres on all sides around Antarctica.
In a decade there are 120 months … so that’s less than two thirds of a sample per month in that critical part of the Southern Ocean nearest Antarctica. They claim an accuracy of ± 0.06° C for their 1950 results … true, that’s the claimed accuracy for the whole of the Southern Ocean, but the situation there is not much better. Extending the area down to 40S increases the samples to a whopping two per month … but the area increases by a factor of four, so the sample density hasn’t gone up at all.
Does anyone truly think that we can estimate the temperature of that huge swath of ocean to a ±0.06°C accuracy by taking a couple of temperature readings per month over thirty million square miles of ocean, bunched in the summer months, with each reading being taken in a very different place all around Antarctica?
Really?
This type of huge underestimation of the true error in various estimations of temperatures, temperature trends, proxy calculations, and other climate measurements is a recurring problem in climate science.
Dennis Nikols, P. Geol. says:
August 17, 2010 at 10:29 pm
“…I think it fair to say the EOF mode has some problems, not the lest of which is a lack of data. These models often look straight forward but like all these thing the devil is in the details. I think one needs to be paying very close attention to the currents in the area too. When you try and relate two different fluid dynamic systems, neither of which is fully understood, together the results can be anything but accurate.”
You are right Dennis, but it’s worst than that. The sea surface is a turbulent system, driven by the wind above and the currents below. It does not have an homogeneous temperature over large areas, rather it is fractal with pockets of warm water in areas of cooler water at all scales. Many many temperature measurements are needed to even get within an accuracy of +/-1K, which clearly we have not got.
Much of the cargo cult science behind CAGW depends on ignoring deterministic chaos and using meaningless linear trends which are cherry picked to provide the expected result.
As this paper from Dr. Curry shows, confirmation bias and the need for continuing government financial support, provides some amazingly wrong conclusions/results.
Willis Eschenbach says:
August 18, 2010 at 12:16 am
Does anyone truly think that we can estimate the temperature of that huge swath of ocean to a ±0.06°C accuracy by taking a couple of temperature readings per month over thirty million square miles of ocean, bunched in the summer months, with each reading being taken in a very different place all around Antarctica?
—————-
Why don’t you test your hypothesis rather than arguing from incredulity? Download some model output, sample the model temperatures at an equivalent sampling rate to the observational data, then test how well you can reconstruct the model mean temperatures from your pseudo-observations.
Its an easy analysis to do, probably less than 50 lines of R code, and could prove your point. But perhaps you prefer to wallow in your logical fallacy.
P Gosselin says:
August 17, 2010 at 10:12 pm
True, but errors in models is no news at all, I expect those, whereas errors in data …
have a look at the source data from which the first EOF is constructed
Bob Tisdale can probably help you
Willis Eschenbach: August 18, 2010 at 12:16 am
Does anyone truly think that we can estimate the temperature of that huge swath of ocean to a ±0.06°C accuracy by taking a couple of temperature readings per month over thirty million square miles of ocean, bunched in the summer months, with each reading being taken in a very different place all around Antarctica?
Figure 1 (b)
http://www.sciencemag.org/content/vol295/issue5558/images/large/se0720194001.jpeg
shows almost no shipboard readings in the area between NZ and Chile, and the majority of the readings from the ’60s and ’70s are concentrated off the east coast of Australia, Argentina, and the Cape of Good Hope. Trying to construct an accurate picture of temperature over the entire area using those scattershot data points would seem to be — *frustrating*…
CIASTO AND THOMPSON2009
In the EN3 dataset, each individual month contains
profiles of temperature for a given location (latitude/longitude) and depth (in meters). The quantity and positions of the profiles varies from month to month, and neither
the locations of the profiles nor the depths at which temperatures are measured are regularly spaced. For example, January 1990 contains 9646 profiles of temperatures,
but not all profiles are sampled at the same depths: the profile at 30N, 22W contains 141 temperature values at irregularly spaced depths from 0 to 2000m,
the profile at 61S, 57W contains 79 temperature value sat irregularly spaced depths from 0 to 300 m, and so on.
Figure 1 shows the number of available vertical temperature profiles for the period 1990–2006 for the extratropical South Pacific. In actuality, the EN3 archive extends
back to January 1950, but there are virtually no profile data in the SH prior to 1990. After 1990, temperature profiles are concentrated in the following three regions: 1) off the southeast coast of Australia, 2) to the north of New Zealand, and 3) to the south of Tasmania
richard telford: August 18, 2010 at 1:06 am
Its an easy analysis to do, probably less than 50 lines of R code, and could prove your point. But perhaps you prefer to wallow in your logical fallacy.
Where is the logical fallacy in saying you can’t accurately estimate the temperature of thirty million square miles of ocean to ± 0.06°C when you have measurements for less than half the area, and most of those were taken during the summertime?
Judith Curry won’t be pleased.
Once again in climate science we see that actual data is inversely proportional to certainty, i.e. the less data there is around the more certain the climate scientists are with their conclusions.
We have seen this before with Steig and co, where they had to invent data to conclude that Antarctica was both warming and cooling at the same time.
richard telford says:
August 18, 2010 at 1:06 am
I love how folks want me to do their investigation for them. But please, be my guest, don’t let me stop you … in any case, in that study I was discussing in that particular comment, there isn’t a word about model results, only observations, so I haven’t a clue what you are talking about.
Finally, I am not arguing from incredulity. I am applying the reasonableness test. Like I said, thirty million square miles of ocean, with two samples per month … sure, the stated error bounds of ±0.06° may well be the statistical error of their calculations. But if you believe that two temperature measurements per month, usually in widely separated locations, with few repeat measurements, are enough to tell us the average temperature of mid-depth ocean water over 15% of the surface of the earth to within ±0.06°C, I’m not sure what I can tell you.
But like I said, report back with your findings, if you’re right it shouldn’t take you long …
Steven Mosher says:
August 18, 2010 at 1:21 am
Mosh, from what the study says, what I show is the source data from which the first EOF shown in Fig. 1 (a) is constructed … what am I missing here?