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Watts Up With That's ignorance regarding Antarctic sea ice

Posted on 9 March 2010 by John Cook

In recent weeks, the Watts Up With That blog has focused several times on Antarctic sea ice. Specifically, Steven Goddard mentions that Antarctic sea ice has increased over recent decades, speculating this is probably due to cooling around Antarctica. In one post, he comments that "sea ice extent has been increasing over time around Antarctica – this is consistent with the idea that temperatures are cooling". In another post, he repeats this theme: "Antarctica is cooling and sea ice is increasing (makes sense – ice is associated with cold)". If his intent is to accurately describe why Antarctic sea ice is increasing, he would be better served first checking what observations and peer-reviewed research have to say on the matter.

The most common misconception regarding Antarctic sea ice is that sea ice is increasing because it's cooling around Antarctica. Goddard commits this error on several occasions. The reality is the Southern Ocean surrounding Antarctica has shown strong warming over the same period that sea ice has been increasing. Globally from 1955 to 1995, oceans have been warming at 0.1°C per decade. In contrast, the Southern Ocean (specifically the region where Antarctic sea ice forms) has been warming at 0.17°C per decade. Not only is the Southern Ocean warming, it's warming faster than the global trend.


Figure 3: Surface air temperature over the ice-covered areas of the Southern Ocean (top). Sea ice extent, observed by satellite (bottom). (Zhang 2007)

If the Southern Ocean is warming, why is sea ice increasing? There are several contributing factors. One is the drop in ozone levels over Antarctica. The hole in the ozone layer above the South Pole has caused cooling in the stratosphere (Gillet 2003). A side-effect is a strengthening of the cyclonic winds that circle the Antarctic continent (Thompson 2002). The wind pushes sea ice around, creating areas of open water known as polynyas. More polynyas leads to increased sea ice production (Turner 2009).

Another contributor is changes in ocean circulation. The Southern Ocean consists of a layer of cold water near the surface and a layer of warmer water below. Water from the warmer layer rises up to the surface, melting sea ice. However, as air temperatures warm, the amount of rain and snowfall also increases. This freshens the surface waters, leading to a surface layer less dense than the saltier, warmer water below. The layers become more stratified and mix less. Less heat is transported upwards from the deeper, warmer layer. Hence less sea ice is melted (Zhang 2007).

Antarctic sea ice is complex and counter-intuitive. Despite warming waters, complicated factors unique to the Antarctic region have combined to increase sea ice production. The simplistic interpretation that it's caused by cooling is false. It's unfortunate that Steven Goddard has publicly speculated on why Antarctic sea ice is increasing without fully investigating what observations and research have found. The result is that many readers at Watts Up With That have been misled on the true and fascinating nature of Antarctic sea ice.

Note to regular readers: yes, I know I'm rehashing content from Antarctic is gaining ice. Sometimes a little repetition is required for the message to sink in.

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Comments 1 to 50 out of 89:

  1. Is there more ice forming around Antarctica or is less ice being spread over a bigger area?
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  2. Slightly OT...have you already published a blog explaining what kind of observed phenomena might be "not explained by" / "incompatible with" / "inconsistent with" anthropogenic global warming?
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  3. 1. "Another contributor is changes in ocean circulation." And by us (many) of skeptics is the main reason. Interesting for me here is the example of this graph: http://i34.tinypic.com/dcora.jpg http://i34.tinypic.com/dcora.jpg; and Indian Ocean Dipole (IOD) ... 2. I also repeat his earlier comment: "... most of Antarctica, over the past 35 years, is cooled (http://www.sciencedaily.com/images/2008/05/080507132855-large.jpg), which is typical for the Millennium cycles, although the reasons may be Miscellaneous (e.g.: "A doubling in snow accumulation in the western Antarctic Peninsula since 1850." E.R. Thomas et. al., 2008)." ... and the trend in the southern ocean temperature increase is significantly lower than the north ...
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  4. Could you please show how this stratosphere cooling and troposphere warming is consistent with GCM projections for antarctic region? Also those models project the observed increase in sea ice extent?
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  5. Sordnay, read the 'Gillet 2003' link in the article itself : "Recent observations indicate that climate change over the high latitudes of the Southern Hemisphere is dominated by a strengthening of the circumpolar westerly flow that extends from the surface to the stratosphere. Here we demonstrate that the seasonality, structure, and amplitude of the observed climate trends are simulated in a state-of-the-art atmospheric model run with high vertical resolution that is forced solely by prescribed stratospheric ozone depletion. The results provide evidence that anthropogenic emissions of ozonedepleting gases have had a distinct impact on climate not only at stratospheric levels but at Earth's surface as well."
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  6. The Steven Goddard piece was posted on WUWT only yesterday but in 24 hours almost one hundred comments were made. That suggests a surprising interest in ice caps.
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  7. As far as I can see the fuss is not about consistence but existence (of gorwth in Antarctic sea ice extent). IPCC AR4 WG1 4.4.2.2 Figure 4.8 caption says "Antarctic results show a small positive trend of 5.6 ± 9.2 × 103 km2 yr–1 [...] the small positive trend in the SH is not significant" which is not true. Antarctic sea ice extent is increasing (for whatever reason) and the trend is significant. Comiso 2003 referenced in IPCC AR4 is a book chapter (not peer reviewed), there is no updated version and the 5.6 km2 figure is nowhere to be found in it. The statement in the book that comes closest to the IPCC claim is "In the Southern Hemisphere, the trends for extent in each season are basically insignificant except for autumn". IPCC has omitted any reference to fall conditions. However, not even Comiso is right. According to Zhang Hadley Centre finds a 27 × 103 km2 yr–1 (significant) inrease rate, almost five times more than the IPCC figure. I don't care much for explanations until facts are not established firmly.
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  8. When you look at the total ice coverage of the planet it comes out as roughly; 90% Antarctic ice sheet 9% Greenland ice sheet 1% Arctic & Antarctic sea ice, all other land ice The Antarctic and Greenland ice sheets are both melting. The Arctic sea ice and the world's glacier mass are both decreasing. But there is that fraction of 1% in the Antarctic sea ice which has grown, so 'skeptics' insist that shows cooling. It is absurdly illogical to take the trend observed in less than 1% of the planet's ice over the opposite trend seen in the other 99+%, but that isn't stopping far too many from going there anyway.
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  9. The explanation of how we have more sea ice floating on warmer water (with interleaving warmer and cooler layers) is very confusing indeed. When a kG of ice freezes it gives up latent heat energy equal to 80 times that of raising the temperature of a kG of seawater by 1 degC. Conversely melting a kG of ice will absorb about 80 times the heat energy of cooling seawater by 1 degC - or you need to cool 80kG of seawater by 1 degC to melt 1kG of ice. That transport of heat energy must go somewhere - whether by complex Antarctic circulations or movement farther afield. Doing an energy balance for Antarctica and its unique circulation alone would suppose it is a closed system - and if this is assumed in large part, then an increasing mass of sea ice would give up its heat to the surrounding water and air - and would raise their temperatures. Therefore increasing mass of sea ice would be consistent with warming air and seawater and transport of heat by complex circulations - not necessarily anything to do with external AGW forcing at all.
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  10. Is anyone surprised at Watts? Just last week he claimed that an article from 1989 proved global warming was a hoax. I'm not sure what was dumber - that claim, or Andrew Bolt saying that the Skeptical Science iPhone app was a secret conspiracy by Al Gore. You can give your thoughts here: http://akwag.blogspot.com/2010/03/watts-vs-bolt-whos-dumbest-denier.html
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  11. JMurphy #5 I would like to read it, but I only have access to the abstract. Are those state-of-the-art models the same as GCM used for IPCC AR4 proyections?
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  12. You should consider using rel=nofollow in your links to climate denier sites. http://en.wikipedia.org/wiki/Nofollow
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  13. Goddard has been wrong several times on WUWT. Before this, he misrepresented increased snowfall as an indicator that climate may be cooling: See: Cherry Snow and Snow.
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  14. Goddard also states Shakhova gets current Global Methane levels wrong by quoting inaccurate NYT article. lol
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  15. P.S. What stbloomfield said: > You should consider using rel=nofollow in your links to climate denier sites. http://en.wikipedia.org/wiki/Nofollow By linking to Watts without 'nofollow', you're giving him 'authority' so that Google will rank him higher.
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  16. Well, don't forget it's Goddard who insisted that there's dry ice in the Antarctic ...
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  17. Wouldn't fresher water also have a higher freezing point, or is this effect just not as significant as the stratification and cyclonic wind effects?
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  18. You might want to mention that the sea ice forming does not accumulate into ever more sea ice over time -- most people don't know that it melts away every year.
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  19. Well, looking at your graph, I seem to be mistaken.
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  20. Tenney, the graph shows the average annual extent. As you said, each year most of the sea ice around Antarctica melts away. Even that remaining ice coverage at the Summer minimum point has increased slightly (though it is down this year), but the primary change has been increased ocean area covered by ice at the Winter maximum.
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  21. The first thing I would point out is that some people here need to look at the y-axis on the temperature graph. The average temperature has changed from -12.7C to -12C. Both of those temperatures are well into the range where sea ice is going to be forming. The roughly 5% change in temperature would mean less sea ice, if all other things were constant, but it would not be hard for some other factor to compensate for it. And as far as that goes, I've got more confidence in the peer-reviewed work than the blog comments.... #8 Berényi Péter, you assert that Comiso (2003) is not peer reviewed because it is a book chapter. However, many such books are peer reviewed (most, I would say). Do you make this assertion based on knowledge of the situation or an an assumption.
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  22. What an amazing article! You selectively edited my sentences, and forgot to attribute the claims of cooling and expanding ice to NSIDC and UAH. BTW - UAH data shows South Pole oceans cooling, not warming. http://nsidc.org/arcticseaicenews/index.html "Sea ice extent in the Antarctic has been unusually high in recent years, both in summer and winter. Overall, the Antarctic is showing small positive trends in total extent. For example, the trend in February extent is now +3.1% per decade. However, the Amundsen and Bellingshausen Seas show a strong negative trend in extent. These overall positive trends may seem counterintuitive in light of what is happening in the Arctic. Our Frequently Asked Questions section briefly explains the general differences between the two polar environments. A recent report (Turner, et. al., 2009) suggests that the ozone hole has resulted in changes in atmospheric circulation leading to cooling and increasing sea ice extents over much of the Antarctic region."
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  23. Unfortunately, In this debate considering the sock'em clown "arguments" that contrarians are endlessly circulating - you have every right (& cause) in the world for a little rehashing. PS. Fantastic blog and thank you so much for the bulletins your emailing. Very Helpful.
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  24. re: #22 How can satellite measurements show the temperatures below the ocean's surface? Duh!
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  25. Tenney, Look closer at the graph above. It is labeled "Southern Ocean Surface Air Temperature." Do you really think then surface air temperature is measured "below the ocean's surface?" The author of this piece is lumping a large area of Southern Ocean together. Look at the ocean near Antarctica - it is cooling. http://climate.uah.edu/25yearbig.jpg My piece on WUWT is titled "NSIDC Reports That Antarctica is Cooling and Sea Ice is Increasing" http://wattsupwiththat.com/2010/03/08/nsidc-reports-that-antarctica-is-cooling-and-sea-ice-is-increasing/
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  26. Sordnay wrote : "Are those state-of-the-art models the same as GCM used for IPCC AR4 proyections?" I doubt it : are you using the same computer/computing power/programs that you were using about 5 years ago (considering the length of time to gather the data used for the reports released in 2007) ?
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  27. Steve Goddard, I'm sorry but you either KNOW that you are playing fast and loose with the facts or SHOULD. The NSIDC source you cite does NOT say that Antarctica is cooling. It says, in passing, that another source entirely (Turner 2009) suggests that the ozone hole might be causing circulation changes which in turn might cause cooling. That statement about a potential cooling influence is VERY different from a statement that the continent as a whole HAS cooled. Next you cite UAH satellite records as proof that oceans around Antarctica are cooling... unfortunately those readings are taken of conditions about 4.5 KILOMETERS (i.e. higher than the Rocky Mountains) above the ocean and thus tell us precisely nothing about ocean temperatures.
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  28. This is simply more distortion and obfuscation from WUWT. Steve Goddard has also chosen to ignore this image: http://earthobservatory.nasa.gov/IOTD/view.php?id=8239 John maybe you could help an ignoramus like I am to insert the image for all to see? While one could argue that the SAT trends over the Antarctic are unreliable b/c the satellite has trouble distinguishing between clouds and ice in this region, the same is not true for the surrounding oceans. Note, these are only "skin" temperatures, but there has been clear and marked warming of the southern oceans between 1981 and 2007. The increase in "skin" temperatures are corroborated the fact that 0-700 m OHC in the southern oceans is also increasing steadily: http://i34.tinypic.com/4hpklk.png As for this claim by Goddard, "BTW - UAH data shows South Pole oceans cooling, not warming." Actually, the UAH data estimate tropospheric air temperatures, not ocean temperatures. Anyhow, Goddrad should be looking at the more reliable TLT data (lower troposphere) from RSS: http://www.remss.com/msu/msu_data_description.html#msu_amsu_trend_map_tlt Look at the line graph on the RHS. Nope, no cooling. Analysis of the TLT data between 60 and 72.5 S show a negligible positive slope over the past 30-yrs, certainly not even close to being stat. sig. So one could accurately state that the TLT data show that the lower troposphere above the southern oceans (south of ~60 S) has not cooled or warmed significantly in the last 30 years John has provided some excellent references here which describe this intriguing and counterintuitive increase in seasonal Antarctic sea ice. What one also should keep in mind is that the Arctic ocean is losing ice faster than any gains being made in seasonal Antarctic sea ice, with the following net loss of global sea ice: http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/global.daily.ice.area.withtrend.jpg And let us not forget the recent findings from analysis of GRACE data which show the WAIS and even the EAIS losing ice mass at an accelerated rate, and the fact that the PIG exceeded its tipping point in the late 90s (BAS). Perhaps this "surge" of fresh water is adding to the stratification of the southern oceans mentioned by John. IMHO, I think that this increase in Antarctic sea ice is an interim phase. In coming decades the southern oceans will have warmed enough that the northern limit of the seasonal ice extent will start to recede. One also wonders what will happen if and when the ozone hole begins to repair (circa 2050). It could be the perfect storm... PS: A caution to readers. Goddard has a history when it comes to being selective with his data: http://tamino.wordpress.com/2010/02/22/snow/ http://tamino.wordpress.com/2010/02/18/cherry-snow/ Apparently defeated in trying to distort/misrepresent the N. Hemisphere cryosphere data he has now set his target on the southern cryosphere.
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  29. Albatross, You obviously didn't read my article. The NASA image you say I "ignored" http://earthobservatory.nasa.gov/IOTD/view.php?id=8239 is right at the top of the my article! http://wattsupwiththat.com/2010/03/08/nsidc-reports-that-antarctica-is-cooling-and-sea-ice-is-increasing/ Do you often comment on articles you haven't read or even glanced at?
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  30. #9 CBDunkerson at 00:29 AM on 10 March, 2010 "The Antarctic and Greenland ice sheets are both melting" And how do you know that? Volume of Greenland ice sheet is 2.85 × 106 km3. Annual loss is esimated to be less than 2.5 × 102 km3. If you take it seriously, measurement precision should be better than 10-4. As for Antarctica, annual loss (from peninsula) is estimated to be less than 2 × 102 km3, while ice sheet volume is 3 × 107 km3. Precision of any kind of measurement for ice volume is insufficient to detect a less than 10-5:1 change. Therefore we simply do not know if large ice sheets are gaining or losing mass. They are supposed to lose, but just that. "It is absurdly illogical to take the trend observed in less than 1% of the planet's ice over the opposite trend seen in the other 99+%" No, it is not. You are talking about ice volume ratios. The area covered by southern sea ice is quite large compared to the rest. NH snow (summer) - 8 × 1011 m2 NH snow (winter) - 4.5 × 1013 m2 Arctic ice sheet (Greenland) - 1.7 × 1012 m2 Arctic sea ice (summer) - 7 × 1012 m2 Arctic sea ice (winter) - 1.5 × 1013 m2 Antarctic ice sheet - 1.4 × 1013 m2 Antarctic sea ice (summer) - 3 × 1012 m2 Antarctic sea ice (winter) - 1.8 × 1013 m2 In southern winter it is 43% of all snow/ice covered area on Earth, hardly negligible. Also, melt season down there is only four months and sea ice extends to pretty low latitudes (60S). Therefore it gets a lot of insolation. Having a much higher albedo than open sea water, it has a strong cooling effect.
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  31. Steve, the NASA temp map is at the top of your article... where you dismiss it as incorrect based on the NSIDC's supposed statement that Antarctica is cooling... which you made up. So 'ignored' may not be the most precisely accurate word, but it is in the ballpark. Again, the NSIDC did not say that Antarctica is cooling. They did not even say that 'Turner 2009' says Antarctica is cooling. Indeed, that paper, which is linked in John's article above, doesn't even deal with temperature changes and thus certainly does not support the claims you are making of it. In short, you've dismissed NASA's data showing Antarctic cooling based on no data whatsoever to the contrary... just your misunderstanding or misapplication of a passing phrase on a NSIDC web page.
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  32. CB, NSIDC's complete discussion of Antarctica is below. There is no ambiguity in the discussion - sea ice is increasing and temperatures are cooling. They are very intelligent and thoughtful people, and don't partake in the same intellectual sloppiness as people over here. Why are you ignoring this NASA map? http://earthobservatory.nasa.gov/images/imagerecords/6000/6502/antarctic_temps.AVH1982-2004.jpg "While our analysis focuses on Arctic sea ice, we note that Antarctic sea ice has reached its summer minimum extent for the year, at 2.87 million square kilometers (1.11 million square miles). This was 88,500 square kilometers above the 1979 to 2000 average minimum. Through the austral summer, the total extent of sea ice surrounding the Antarctic continent has remained within two standard deviations of the 1979 to 2000 average. Sea ice extent in the Antarctic has been unusually high in recent years, both in summer and winter. Overall, the Antarctic is showing small positive trends in total extent. For example, the trend in February extent is now +3.1% per decade. However, the Amundsen and Bellingshausen Seas show a strong negative trend in extent. These overall positive trends may seem counterintuitive in light of what is happening in the Arctic. Our Frequently Asked Questions section briefly explains the general differences between the two polar environments. A recent report (Turner, et. al., 2009) suggests that the ozone hole has resulted in changes in atmospheric circulation leading to cooling and increasing sea ice extents over much of the Antarctic region."
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  33. @7 "Antarctic sea ice extent is increasing (for whatever reason) and the trend is significant." Can you elaborate and quantify this generalized statement? Are the trends stat. sig.? If so, at which level of confidence? Also, for which months are you talking about? OK, I have downloaded the sea ice area data from NSIDC for Antarctica for Feb (minimum) and September (maximum) between 1979 and 2009/2010. For Feb: positive trend is not significant at 99%, 95% or 90% level of confidence, p-value is 0.132 (N=32). So trend stat. sig. at only 86.8% level of confidence. For Sep: positive trend is not significant at 99% or 95% level of confidence, p-value is 0.065 (N=31). So trend is sta. sig at 92.5% level of confidence. In my line of work at least, one typically only accepts a trend as being 'significant' if the p-value is <0.05 (95% level of confidence).
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  34. Berényi Péter at 04:22 AM on 10 March, 2010 Easier units on Greenland loss, w/error range: "Using time-variable gravity measurements from the Gravity Recovery and ClimateExperiment (GRACE) satellite mission, we estimate ice mass changes over Greenland during the period April 2002 to November 2005. After correcting for effects of spatial filtering and limited resolution of GRACE data, estimated total ice melting rate over Greenland is – 239 ± 23 km3/year, mostly from East Greenland. This estimate agrees remarkably well with a recent assessment of – 224 ± 41 km3/year, based on satellite radar interferometry data." Satellite Gravity Measurements Confirm Accelerated Melting ofGreenland Ice Sheet Doubtless we can get lost in a myriad of details about GRACE, how it works, what are the system limitations, but of course those will have to account not just for this particular GRACE result but also all other GRACE applications and results of which there are many with plenty of external consistency.
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  35. This thread is getting very contentious very fast. Let's try to keep in mind John Cook's Comments Policy. In particular, it's usually better to say "Ned is mistaken when he claims ..." or "Ned's claims of ... are not borne out by the facts" and leave out the speculation about Ned's motives and personal moral failings. As much as possible, it's also best to avoid snide remarks and stay on topic. I know that when I think somebody is wrong about X it's often tempting to drag in issues Y and Z as a way of demonstrating that she/he is a complete idiot rather than simply mistaken about the issue currently under discussion. That tends to lead to threads full of the same emotional charges and counter-charges seen on pretty much all the other climate science blogs. Sorry for the editorializing. I've had my own comments deleted here (as have many others) for failing to follow the comments policy, and I'm just trying to spare others the embarrassment. :-)
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  36. Someone needs to contact NSIDC to tell them that their summary of Turner et al. (2009) is not quite correct.
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  37. Steven, as you're here and we're talking about solid state water, do you have any remarks about Tamino's destruction of your hypothesis about NH snow cover? Here it is: Cherry Snow There's a recent thread here on snow cover, Does record snowfall disprove global warming where you might want to get your thoughts on Tamino's writeup on the record, so to speak.
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  38. Steve Goddard, first it doesn't matter how many times you quote that passage... the Turner paper which the NSIDC is there referring to DOES NOT include data showing that Antarctica is cooling. It doesn't exist. Because that isn't what the NSIDC web page was saying. You are misunderstanding or misrepresenting them, but in any case... there is no data whatsoever supporting what you are claiming. As to the other NASA map you cite... who is ignoring it? Looks like it shows the warming of the southern oceans just fine to me. See all that red?
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  39. Steve Goddard writes: They are very intelligent and thoughtful people, and don't partake in the same intellectual sloppiness as people over here I understand why you might feel less than thrilled about this thread, but I hope you'll stick around and explore more of the site. John Cook and others have put a lot of effort into creating what's clearly one of the best climate science blogs anywhere. The emphasis on exploring the peer-reviewed literature, and clearly and concisely summarizing the best current understanding of elements of the global climate system, is pretty much unmatched.
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  40. Steve Goddard, the image that you refer people to from EarthObservatory is incorrect. The actual source of the image that you provided is: http://earthobservatory.nasa.gov/IOTD/view.php?id=6502 Below that image they state that: "(Editor’s note: This image was first published on April 27, 2006, and it was based on data from 1981-2004. A more recent version was published on November 21, 2007. The new version extended the data range through 2007, and was based on a revised analysis that included better inter-calibration among all the satellite records that are part of the time series.)" They even provide a link to the correct image at: http://earthobservatory.nasa.gov/IOTD/view.php?id=8239 Of note is the marked warming evident over the polar oceans. I have provided a caveat about the temperature trends over the continent itself. Also, please read the actual report by Turner et al. (2009), nowhere do they state that Antarctica has cooled. They state: "a. The loss of stratospheric ozone has intensified the polar vortex, a ring of winds around the South Pole, altered weather patterns around the continent, and increased westerly winds by about 15% over the Southern Ocean in summer and autumn. b. This has resulted in the Antarctic becoming more isolated and there being little change in surface temperature across the bulk of the continent over the last 30 years." And, "a. The waters of the Antarctic Circumpolar Current (the largest ocean current on Earth) have warmed more rapidly than the global ocean as a whole." And, "a. While sea ice extent across the Arctic Ocean has decreased markedly over recent decades, around the Antarctic it has increased by 10% since 1980, particularly in the Ross Sea region. b. This increase is a result of the stronger winds around the continent, changes in atmospheric circulation and the isolating effect of the ozone hole. c. In contrast, there has been a large regional decrease of sea ice to the west of the Antarctic Peninsula, because of changes in the local atmospheric circulation." Report summary at: http://www.scar.org/publications/occasionals/ACCE_top_10_points.pdf I encourage readers here to read the report.
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  41. Ned at 04:55 AM on 10 March, 2010 Ned's advice is good. Especially, never forget that you're writing for a silent audience most of whom have no notion of past issues or why patience may be wearing thin. Despite the fact that Steven has been wrong so often in the past and has left so many challenges to his accuracy unanswered, it is best to treat each new mistake individually.
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  42. @7: "Antarctic sea ice extent is increasing (for whatever reason) and the trend is significant." @32 (Quoting NSDIC) "Through the austral summer, the total extent of sea ice surrounding the Antarctic continent has remained within two standard deviations of the 1979 to 2000 average." These statements are contradictory. If the extent of the ice has remained within 2 standard deviations of the mean, then it cannot be significant at the 5% level. Phil Jones could explain it to you, don't ask teh Daily Mail.
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  43. It does seem a bit strange to refer people to either the older version or the newer version of that graphic as evidence of cooling in the Southern Ocean. Both versions actually show the ocean warming; the only large differences involve the temperature trend over land (formerly cooling, now warming).
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  44. Goddard,re #29. I am commenting on what John posted in his article, and limiting my discussion to the science being discussed here on this thread. That said. I am curious then why you chose to post the incorrect image here at #32, and not the same (and correct) image you used in your report at WUWT. I am "ignoring" that map because it has been superseded by a superior product. The science has advanced. And, if you stick around long enough, I think that you will find this site intellectually stimulating rather than "sloppy".
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  45. There is only one very brief note in Turner 2009 about temperature trends. Under Results, they say: "[14] The increase in southerly flow will give lower air temperatures, and will help maintain the polynyas along the coast. Combined, these will lead to greater ice production [Comiso, 2000] and also promote enhanced ice advection northwards." That's all. In the context, it's not even clear whether this is suggesting that the increased southerly flow associated with the stratospheric ozone hole will make air temperatures over the Southern Ocean cooler than they were previously (i.e., an actual cooling trend) or just cooler than they would be without the ozone hole (i.e., not necessarily actual cooling over time). Regardless, however, this is irrelevant. The proper place to determine whether the Southern Ocean is currently warming or cooling is to look at actual measurements, not at the results of climate model experiments like Turner 2009. Actual data show the ocean is in fact warming. What's interesting about Turner 2009 (and it is interesting ... I'd encourage you to read the whole paper) is that it discusses the mechanisms of how and why sea ice in the Southern Ocean behaves as it does. If you're only interested in the bottom line ("Will sea ice extent increase or decrease over the course of this century?") here's what Turner 2009 concludes: "Projections of the climate for the rest of this century using the AR4 models suggest a large decrease (approximately 30%) in Antarctic sea ice by 2100 [Arzel et al., 2006; Bracegirdle et al., 2008] as stratospheric ozone levels recover but greenhouse gas concentrations rise. We can therefore expect to see a gradual slow down in the rate of increase of SIE before the reduction takes place later in the century. Many of the models used within the AR4 exercise incorporate an estimated recovery of stratospheric ozone amounts during the spring, with the ozone hole recovering by the second half of the century. This would tend to reduce the wind speeds around the continent and presumably result in a reversal of the trends in SIE that we have examined here."
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  46. About RSS TLT Channel, there is something that bothers me, it's the only channel that is not registered to Latitude -80º it only reaches to -70º so almost the whole Antarctica is not measured. It's also noticeable the difference between version 3.2 and 3.1 the difference is greater than the anomaly registered at Antarctica or better, near Antarctica. see last figure at http://www.remss.com/data/msu/support/Changes%20from%20TLT%20Version%203.1%20to%203.2.pdf "We reduced the systematic bias that occurs due to spatial-derivative effects in the TLT extrapolation process that can be large at high latitudes. The effects of this bias are particularly large near Antarctica. (see Section 2c in the preprint for a discussion)" Someone could help me locating that Section 2c? thanks
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  47. Hey Doug, You must have missed the fact that winters during the past decade were the snowiest on record in the Northern Hemisphere. http://wattsupwiththat.com/2010/03/02/2001-2010-was-the-snowiest-decade-on-record/ Tamino hinted that winter snowfall might be declining, but he just couldn't prove it yet. (Declining to a record maximum is an interesting concept.) If you want to discuss science, come do it over on WUWT. I've spent enough time in this Wonderland already, where down is up and up is down.
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  48. Sordnay writes: omeone could help me locating that Section 2c? thanks That's referring to section 2(c) of the preprint of Mears & Wentz manuscript about the TLT channel posted in the same folder on the RSS website. See pages 9-10 of that pdf ("Construction of the RSS V3.2 lower tropospheric temperature dataset from the MSU and AMSU microwave sounders"). The manuscript was published as Mears & Wentz 2009 in the AMS's Journal of Atmospheric and Oceanic Technology. You might want to refer to the published version rather than the preprint (I'm not sure whether there were any changes).
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  49. Steve Goddard @47: I'd appreciate an answer to my question @44: "I am curious then why you chose to post the incorrect image here at #32, and not the same (and correct) image you used in your report at WUWT?" Do you also now agree, after reading the links to Turner et al. (2009) and Ned's comments, that Turner et al. (2009) did not claim that Antarctica is cooling? In the spirit of honesty and correctness, I would suggest that you correct your blog at WUWT to reflect the science (from the scientific literature) and other facts presented to you here concerning the southern oceans and Antarctic sea ice. We all make mistakes, one true test of scientific integrity is admitting to having made them and then promptly correcting them. PS: I'm sorry but, with respect, WUWT is not a science blog.
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  50. Steve Goddard writes: You must have missed the fact that winters during the past decade were the snowiest on record in the Northern Hemisphere. Actually, that and much more are discussed in great detail in John's post that Doug linked to, elsewhere on this site: Does record snowfall disprove global warming? I'd second Doug's remark encouraging you to check out that page, and comment if you see fit. Goddard continues: If you want to discuss science, come do it over on WUWT. No, thanks. Many of us have had more than ample negative experiences with WUWT. I'm honestly not trying to be insulting or dismissive, but there's very little actual science there. As far as I can tell it's primarily about entertainment. If you stick around here, you'll quickly find more substantive discussion and better food for thought. Ultimately, real science is more interesting than fake science. Cheers, Ned
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