UPDATES: New NSIDC data and a press release from them added below.
While some folks (Joe Romm in particular) are touting the recent University of Bremen press release suggesting a new record low has been met, declaring record minimum Arctic extent was reached on Sept 8 at 4.24 million km2, (See http://iup.physik.uni-bremen.de:8084/amsr/minimum2011-en.pdf) five other sources of sea ice data, NSIDC and JAXA, DMI, Cryosphere Today, and NANSEN don’t agree with that new record claim (at least not yet). While still far from certain, as weather, wind, and ocean currents could still force a turn downwards, the NSIDC graph suggests we may have turned the corner this year.
[UPDATE: This extent graph above (dated 9/12) was updated by NSIDC since posting this story ~ 6AM this morning, and it shows further deviation from 2007, compare to the NSIDC graph of 9/11 below.]
Below, I’ve added a vertical line to show the turning point for the 1979-2000 average (in red) and how it compares to the current NSIDC data.
The JAXA graph, which uses a different satellite sensor (AMSRE vs SSMI) also suggests that we didn’t yet reach a new record low and that we may have turned the corner.
For extent, only the University of Bremen (shown below) shows this year to be lower, and has no turn. It uses the same SSMI sensor as NANSEN and NSIDC, it uses the same AMSRE sensor as JAXA, which doesn’t show a record low, so the difference must be in processing of the data:
The wording from their press release hardly seems scientific and more than a bit over the top:
Alerting message from the Arctic: The extent the the Arctic sea ice has reached on Sep. 8 with 4.240 million km2 a new historic minimum (Figure 1). Physicists of the University of Bremen now confirm the apprehension existing since July 2011 that the ice melt in the Arctic could further proceed and even exceed the previous historic minimum of 2007. It seems to be clear that this is a further consequence of the man-made global warming with global consequences. Directly, the livehood of small animals, algae, fishes and mammals like polar bears and seals is more and more reduced.
The answer to why such language might be used, perhaps prematurely in the face of other datasets which presently disagree, may be found in the proximity of the upcoming Climate Reality Project (aka the Gore-a-thon) on September 14-15. Al needs something to hold up as an example of gloom, since sea ice didn’t repeat the 2007 low in 2008, 2009, or 2010, and the Antarctic has not been cooperative with the melt meme at all, remaining boringly “normal” and even above normal last year.
We’ll know the answer when we see if this Bremen missive is included in Al’s upcoming presentation.
As for whether or not Arctic sea ice extent turned the corner this year, note below that in the prime ice areas, surface air temperature is well below freezing. So. it is up to the wind and ocean currents and other vagaries of weather to determine if we have in fact bottomed out, or if there’s still some loss to come.
If it has turned the corner, it will be about a full week earlier than usual. There could still be another downward blip, as happened in 2010 and in 2007, so I’m not ready to call a turn for certain yet, but it does look encouraging.
Stay updated with all of the latest plots and maps at the WUWT Sea Ice Reference page. Readers may also be interested in the WUWT forecast submission to ARCUS and the notes with it.
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UPDATE2: NSIDC has posted an update in their Sea Ice News section, which I’m reposting below in entirety for WUWT readers:
Overview of conditions
On September 10, Arctic sea ice extent was 4.34 million square kilometers (1.68 million square miles). This was 110,000 square kilometers (42,500 square miles) above the 2007 value on the same date. The record minimum Arctic sea ice extent, recorded in 2007, was 4.17* million square kilometers (1.61 million square miles).
The rate of decline has flattened considerably the last few days: Arctic sea ice is likely near its minimum value for the year. However, weather patterns could still push the ice extent lower. NSIDC scientists will make an announcement when ice extent has stopped declining and has expanded for several days in a row, indicating that the Arctic sea ice has reached its lowest extent for the year and has begun freezing over. During the first week of October, after data are processed and analyzed for the month of September, NSIDC scientists will issue a more detailed analysis of this year’s melt season and the state of the sea ice.
NSIDC’s sea ice data come from the Special Sensor Microwave Imager/Sounder (SSMIS) sensor on the Defense Meteorological Satellite Program (DMSP) F17 satellite. This data record, using the NASA Team algorithm developed by scientists at NASA Goddard Space Flight Center, is the longest time series of sea ice extent data, extending back to 1979.
Other sea ice data are available from other data providers, using different satellite sensors and sea ice algorithms. For example, data from the University of Bremen indicate that sea ice extent from their algorithm fell below the 2007 minimum. They employ an algorithm that uses high resolution information from the JAXA AMSR-E sensor on the NASA Aqua satellite. This resolution allows small ice and open water features to be detected that are not observed by other products. This year the ice cover is more dispersed than 2007 with many of these small open water areas within the ice pack. While the University of Bremen and other data may show slightly different numbers, all of the data agree that Arctic sea ice is continuing its long-term decline.
For more information about the Arctic sea ice minimum, see the NSIDC Icelights article, Heading Towards the Summer Minimum Ice Extent.
*Near-real-time data initially recorded the 2007 record low as 4.13 million square kilometers 1.59 million square miles). The final data, reprocessed by NASA Goddard Space Flight Center using slightly different processing and quality control procedures, record the number as 4.17 million square kilometers (1.61 million square miles). NSIDC reports daily extent as a 5-day average. For more about the data, see the FAQ, Do your data undergo quality control?
@R Gates,
Please tell us how much time you’ve actually spent on the firn area of glaciers.
On the Glacier du Géant on Mont Blanc on 19 August last year I was walking around in 50cm of new snow. This is not atypical.
Did it all melt before winter? I don’t know; do you?
Care to explain why?
Or is this analogous to those “it’s too difficult to quantify this factor so we’ll mark it down as playing no role over the long term” assumptions that crop up from time to time in the orthodoxy?
Agreed that the short-term trend is downwards, but this doesn’t tell us a great deal about long-term changes or whether a cycle is at work.
How much warmer was it in Viking times? The seawater was “at least 4 degrees C warmer”
“It is possible to estimate the summer temperature on the basis of the story in Landnámabók (985-1000) about Thorkel Farserk, who swam out to Hvalsey (in Hvalseyfiord) in order to fetch a sheep to make a feast for his cousin, Erik the Red. By way of comparison, Dr. Pugh from The Medical Research Laboratories in England has established on the basis of studies of Channel swimmers and the like, that 10°C would be the lowest temperature that a man who had not been in special training would be able to endure, even if he was fat. The average August temperature of the water in the fiords along this coast now rarely exceeds 6°C. The water in Thorkel’s time must therefore have been at least 4° warmer and probably more than that.”
From: http://www.canadianmysteries.ca/sites/vinland/othermysteries/climate/4157en.html
If the water was that much warmer, air temperatures at the coast would have been warmer as well. We’ve got a ways to go before it is as warm as it was then.
I agree with those earlier commenters who stated that polar ice acts as an insulator, and keeps the ocean’s heat in. I haven’t yet found any scientific studies on this, with properly obtained data and sound data analysis.
However, the warmists maintain that a shrinking ice cap is strong evidence that the Arctic area is warming, and that warming is due to the heat rays beamed down by CO2 in the atmosphere. In reality, ice acts as an insulator and prevents heat from being released from the ocean into the night sky via thermal radiation. Ice acts in a similar way on lakes, as it keeps the lake from freezing solid unless the lake is very shallow. The growing and retreating Arctic ice acts as a negative feedback on the ocean’s heat content. When the oceans are warm, the ice begins to melt at the edges. There is thus more open water that loses heat due to radiation. The ice extent is at a minimum usually around mid-September, which allows great amounts of heat loss in the long polar nights. The oceans then cool, which eventually cools the air, and allows more ice to form in future years. The ocean and ice system oscillates then between more ice and less ice, with the ocean’s temperature and heat content also oscillating but slightly out of phase.
R. Gates says:
September 13, 2011 at 4:52 pm
The last time we had this much CO2 in the atmosphere, (i.e. the mid-Pliocene) we had ice-free Arctic ocean summers. Don’t see how this downward trend can be reversed.
Shouldn’t that read: “The last time we had this much CO2 in the atmosphere, global temperatures were warmer than present for an extended period of time due to natural variation. In response to the warmer temperatures, the oceans outgassed more CO2. This downward trend will continue as long as temperatures increase and/or oceanic cycles ‘behave’ similarly to the way they did then.”
Billy Liar says:
September 13, 2011 at 5:24 pm
@R Gates,
Please tell us how much time you’ve actually spent on the firn area of glaciers.
On the Glacier du Géant on Mont Blanc on 19 August last year I was walking around in 50cm of new snow. This is not atypical.
Did it all melt before winter? I don’t know; do you?
_____
I’ve got no idea on yearly status of this very famous glacier. All my hikes on glaciers have been here in Colorado– primarily Rocky Mountain National Park. In high school a group of us even stupidly pitched our tents on a glacier in the park, and then in the middle of the night it started raining…very messy, slippery, and as there was a cliff down the hill from where we’d pitched the tent…a bit nerve racking for a few moments.
In general of course glaciers of all varieties are declining worldwide. Best to see one now.
R. Gates, in the mid-Pliocene N. America was not yet attached to S. America which probably had an effect on Arctic ice. Of course you would blame the CO2 instead, that’s what you always do.
Josh Grella says:
September 13, 2011 at 6:04 pm
R. Gates says:
September 13, 2011 at 4:52 pm
The last time we had this much CO2 in the atmosphere, (i.e. the mid-Pliocene) we had ice-free Arctic ocean summers. Don’t see how this downward trend can be reversed.
Shouldn’t that read: “The last time we had this much CO2 in the atmosphere, global temperatures were warmer than present for an extended period of time due to natural variation. In response to the warmer temperatures, the oceans outgassed more CO2. This downward trend will continue as long as temperatures increase and/or oceanic cycles ‘behave’ similarly to the way they did then.”
_____
Natural variation isn’t a factor in climate change. You must be thinking of weather. Definite and specific causes create the large differences between climate periods, not “natural variation.” Discovering what these specific causes are for climate differences is what climate science is all about. If it was all just natural variation (i.e. a random walk?) there’d be no reason to study the climate.
As opposed to the CO2 levels of the Pliocene, our current levels above what the Milankovitch forcing and related feedbacks would cause, are caused by the specific activity of humans. As this human activity continues, we will need to look further and further back in time to what happens to the planet. Currently, the mid-Pliocene is probably about right for where we’re headed in the short-term (100-200 years, 560 ppm CO2, 3C warming?). Depending on what other feedbacks may kick in, we may then have to look to the Miocene for evidence.
But of course, perhaps we’ll tackle the fusion energy genie, and then we can afford to geoengineer this planet into whatever we want, putting CO2 and other greenhouse gas levels exactly where they need to be to forestall the next glacial period, creating unlimited food supplies, keeping the oceans healthy, and life will be good.
R. Gates says:
September 13, 2011 at 5:08 pm
“It’s not the exact precision that matters but the trend. Errors would be consistent across measurements, but that would not affect the trend. Simple visual observation of satellite pictures from one year to the next and ground reports from those who’ve actually lived along the shores of the Arctic confirm the trends.”
If the sea ice data record were composed of long term measurements from single instruments riding on single satellites we might be justified in assuming the observed trends were as indicated, but as you are probably aware the reality is far removed from that case. Most of the info on the Sea Ice Reference page is not photos, it’s maps which are the product of extensive manipulation of the raw data.
” Exact numbers to the nearest 1000 sq. km. are not important.”
From the bullet points on the IJIS SIE page
“In principle, SIC data could have errors of 10% at most, particularly for the area of thin sea ice seen around the edge of sea-ice cover and melted sea ice seen in summer. Also, SIC along coastal lines could also have errors due to sub-pixel contamination of land cover in an instantaneous field of view of AMSR-E data.”
It seems to me that assuming that they’re good for +/- 1000km2 is still a large leap of faith
R. Gates: “putting CO2 and other greenhouse gas levels exactly where they need to be to forestall the next glacial period…”
You really think the sun is that predictable? What about GCR? Are you keeping track of the solar system’s position in the Milky Way?
So seeing as much was made of the wind conditions in 2007 and no such conditions exist now, I take it WUWT will now admit Global warming is destroying the Arctic.
R. Gates says:
September 13, 2011 at 6:24 pm
Natural variation isn’t a factor in climate change. You must be thinking of weather.
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Forget Arctic ice, we definitely have a new low in R. Gates’ pseudo-profound pronouncements.
RE: Anything is possible
September 13, 2011 at 9:19 am
The low anomaly in October 2007 was a result of the abnormally late freeze-up that year. The years since then have also seen a similar but smaller drop in anomaly after the date of minimum area as the re-freeze proceeded slower than the typical 1979-2008 rate.
>> criminogenicjamesc says:
September 13, 2011 at 6:48 pm
So seeing as much was made of the wind conditions in 2007 and no such conditions exist now, I take it WUWT will now admit Global warming is destroying the Arctic.<<
Current warming is improving the Arctic. Hopefully it will continue to do so. An ice-free Arctic would be a boon to shipping, fishing, and oil exploration.
If the University of Bremen is using “high resolution information from the JAXA AMSR-E sensor on the NASA Aqua satellite,” how can they compare the 2011 extent against an average 1972–2008? Doesn’t that bias the average toward more ice, since the Aqua satellite was launched only May 2002? Data from 1972 to at least 2001 (30 years) had insufficient resolution to detect small ice and open water features. Isn’t that a splicing together of nonuniform data sources, like Mike’s Nature trick?
criminogenicjamesc says:
September 13, 2011 at 6:48 pm
“So seeing as much was made of the wind conditions in 2007 and no such conditions exist now, I take it WUWT will now admit Global warming is destroying the Arctic.”
Sometimes I just shake my head in wonder.
suyts says:
September 13, 2011 at 5:10 pm
“Satellites…… they aren’t quite as advertised.”
Perhaps we could get Anthony to include that quote somewhere in his header or maybe prominently on the sidebar. Even among the mostly skeptical crowd around here there is a strong tendency to grant any data derived from satellites much more deference than is really justified. Admittedly in most situations the sat data does constitute the BAG(Best Available Guess) no matter what variable is being portrayed. But just because it’s the best we have doesn’t mean it’s the best that’s possible or even that, in the big picture, it’s really all that good. Most of what gets published as sat data is far removed from what the actual instrument on the actual satellite was measuring. If you go to the supporting documentation for these data sets you’ll usually discover that the chain of construction between what was measured and what eventually was published is quite extensive. The authors of this documentation always make rather extravagant claims for the accuracy of what they put out but, if you really examine their logic with a critical eye, their claims rely on the assumption that the multitude of uncertainties that arise at each step of the process tend to be mutually cancelling so that the final error is always much less than the sum of the included errors. This actually seems to be the prevailing view among number crunchers everywhere so it probably is defensible, but my experience of life suggests that errors are much likely to stack than to cancel (Murphy is always in the building)
In general of course glaciers of all varieties are declining worldwide.
False, Gates, and you lie. I can see Glaciers re-forming here in the Wallowa Mountains, the true thermometer of the world, from right outside my window.
Gates, tell me please, do you really think the Teletubbies, and hence the Prophet, alGore, really do constitute a model for reasoned thinking?
“Phil. says:
September 13, 2011 at 12:18 pm
Apart from Lubos not being the most reliable source, RSS doesn’t measure in the Arctic north of 82.5º, it also isn’t a surface measure.”
Thank you for your reply. I would like to comment on each point raised above.
First: “Apart from Lubos not being the most reliable source,”
Keep in mind that Lubos was quoting facts and was not interpreting facts. It is one thing to disagree with someone’s interpretation, but how can straight facts be not reliable? You may or may not agree with how RSS comes up with their numbers and that would be fair enough, but it seems as you are criticizing Lubos who is just quoting RSS. In that article I referenced by Lubos, he had 2011 as the 12th warmest. Interestingly enough, the HADCRUT3 data at the following has the average (to the end of July only though) also at 12th place in the sense that 11 other yearly 12 month averages were above the 0.342 which was the average to the end of July.
http://motls.blogspot.com/2011/09/rss-amsu-jan-aug-2011-second-coldest-in.html
So I had no reason to believe that Lubos was not in the ball park with his analysis.
Second: “RSS doesn’t measure in the Arctic north of 82.5º,”
True, and the area north of 82.5 degrees is 1/230 of the total area of Earth, so just because this small area is missing does not mean that you cannot draw the proper conclusions as to whether or not global warming is occurring or not. And the referenced article did talk of ‘global warming’ and not just warming in the northern Arctic.
Third: “it also isn’t a surface measure.”
True, but as I said above, HADCRUT3 had very similar results and HADCRUT3 IS a surface measure. So I do not see this as being a huge issue.
Dave Wendt says:
September 13, 2011 at 7:58 pm
(Exactly correct!)
====================================
Dave, I’m working on it. At some point, I’ll be able to point and say “Here! Here is where is wrong!” But, I’m not even close, yet. But, while I’m far away from that point, I’m getting closer to the point where I can say, “Here is where the satellites lied to us.”
In the end, we all base everything on assumptions. The greatest assumption is, someone told us the truth.
James “suyts” Sexton
Anthony you absolutley WERE disingenuous about the CT Anomaly plot. Not just because you didn’t report that the ~3M sqkm anomaly happened in October but also because the 2007 anomaly was measured against 1997 – 2005 and the 2011 Anomaly will be measured against the 1997 – 2008. Which means that even IF 2011 only equalled the 2007 Anomaly, it would have significantly beaten it.
Other misnomers on here.
The Parry Channel of the NW passage was discovered by Dog Sled and has not been open water in modern human history before 2007.
Amundsen navigated the shallow inshore NW passage from *1903 to 1906*. He had to overwinter twice during the attempt when his ship was caught in solid ice as he was jumping form lead to lead in *summer*
Ice breakers (even the nuclear one’s) can only navigate through about 1-2M of solid ice. In the 1950’s and 1960’s icebreakers had to navigate leads or the shallow inland passages because of the thickness of the ice. Just read any book that talks about icebreakers from the 50’s or 60’s. They talk about icebreakers virtually smashing themselves to pieces when having to urgently force their way through the ice. Today they cruise all over the arctic with impugnity even if they are only 1m capable.
This site reminds me of the guy who threw himself off the office block and could be seen talking to himself. When someone opened a window to hear what he was saying, he could be heard saying “So far So good”.
This site will go down in history with the flat earthers. Very little in this life is more certain.
Time to wake up and stop finding excuses to ntipick. It’s like sitting in a buiolding which is being demolished all around you and finding comfort in the fact that less flakes of paint fell off the walls today than yesterday.
Not very clever.
Hmmm uptick in arctic ice with the 24 hours of Climate Reality about to start. I got it, its the Gore Effect due to the Gore-a-thon.
DMI is indicating the Gore effect:
http://ocean.dmi.dk/arctic/plots/icecover/icecover_current.png
philincalifornia says:
September 13, 2011 at 6:54 pm
R. Gates says:
September 13, 2011 at 6:24 pm
Natural variation isn’t a factor in climate change. You must be thinking of weather.
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Forget Arctic ice, we definitely have a new low in R. Gates’ pseudo-profound pronouncements.
Oh, c’mon. Give R. Gates a do-over. It’s easy to let a couple of glaciations and interglacials slip your mind, not to mention the odd Roman Optimum or LIA here and there. Happens all the time.
Mycroft says:
September 13, 2011 at 12:08 pm
yes and when the southern ice extent reached record levels a couple of years ago, the shrill
of warmists doom mogering was ever so conspicuous by its absence wasn’t it old chap
———
The global sea ice area anomaly has been largly negative since 2001… I think that’s what you would have been directed too when you tried to “chreey pick” a few years of high antartic sea ice.
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/global.daily.ice.area.withtrend.jpg