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?
Why is that a “worrying thing” and not a welcoming thing? A warmer Arctic ocean means open sea lanes, and easier resource extraction. A warmer sub-Artic means more land for crops. A warmer temperate zone means more shirt-sleeve weather (which is about to disappear here in New England, as Winter looms). What’s not to like?
/Mr Lynn
It’s so close that it really doesn’t matter if it does or doesn’t set a new low.
On the Sea Ice page, look at the
Arctic Sea Ice Concentration – Same Date Compared With 2007 [Sept 9]
Compare Alaska Brooks Range and Eastern Siberia. There is much more ice and snow in 2011. Is that an early snowfall?
Luther Wu … “icebreakers” …
Ya know .. I’ve always wondered what effect they have had on arctic ice. I mean …. kitchen table experiment … I always notice that crushed ice melts faster than a solid block. Maybe the low arctic ice extent and area have nothing to do with Global Warming .. but with Ice Breaker Ships carving the ice up into crushed slush.
I say .. we ban icebreakers from the arctic for awhile and see what happens!
….. hmmmmmmmmmmm
How convenient it is to exploit minor disagreement between extent datasets as evidence of large uncertainty to distract attention from the record in sea ice AREA and VOLUME.
And to distract attention from the fact that you and your readers have ‘predicted’ this year’s minimum extent would bottom out at 5,5, sorry 5,1, oops 4,5 million square kilometers. That’s a mere 30% off. I’ve got no problem with that…
Luther Wu says:
September 13, 2011 at 5:37 am
Quick! Run a bunch of icebreakers around the Fram straits- we gotta get that ice down to at least 3 times the size o’ Texas, just so we can listen to the warmists howl.
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Indeed, the Russians have a fleet of nuclear powered ice-breakers, they’ve been very active in the arctic this year.
Certainly looks like this year will be “near” 2007. All the CO2 added to the atmosphere since 2007 has increased ice melt by… not much.
I’d be a lot more “alarmed” if ice extent were increasing!
North Pole cam shows we’re near a “tipping point”. If all that ice slides off the edge of the earth, it will prove the earth is flat, eh? 🙂
Best,
Frank
At high longitudes the ice edge was very stable for weeks / months. And now, there is accumulation there.
Two points:
1. I believe the Cryosphere Today record low anomaly in 2007 occurred in October, not at the time of minimum area. Indications that I’ve seen show that this year is very close and perhaps lower than 2007 in terms of minimum area.
2. The minimum extent has an average date of Sept. 12. So if we are at a minimum, it’s about average (maybe a couple days early), not a week early.
NSIDC will be posting an update in a couple of hours and we’ll be watching our data closely and will announce the minimum for our data when we are confident there won’t be further decline. We’ll also probably comment on the Bremen data and the reasons for it’s difference with other measures.
Walt Meier
NSIDC
REPLY: Thanks for commenting Walt.
1. That may be true, I don’t know for sure.
2. This shows just one more reason for NSIDC to post daily value data as JAXA does (as you’ve promised to do) Your graph x and y axis is too coarse to make an accurate numerical determination. Mostly though I was referring to JAXA, which gives us a better handle on minimums due to JAXA providing such data and has a shorter year span than NSIDC.
– Anthony
Martin van Etten says:
September 13, 2011 at 5:32 am
It’s a small difference indeed, 2007 and 2011; however, it is not interesting which year will be ‘winning’, it is the downward trend that is important;
2007 was an extreme year whith an exceptional low sea ice extent, 2011 is catching up while changing the linearity of the downward trend of minimal sea ice extent into an exponential curve to a sea ice free summer within a few years; that is the real worrying thing;
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lol, depends on how you graph it. I think what you’re seeing is the bottom of a sine wave. I’m waiting until the end of Sep. but if you graph Sep 2007 -Sep 2011, you won’t see anything worrying. But even if we’re exponentially curving downward, it isn’t particularly worrying. I’m just hopeful some companies in the U.S. are prepared to exploit the additional shipping lanes available, if it were to come to be. But, the MYI improvement over last year seems to indicate its not gonna happen. http://nsidc.org/images/arcticseaicenews/20110405_Figure5.png …… we’ll see after all of the hyperbole settles down.
Three days of increase now according to Jaxa.
On average, today (day 255) is the last day of declining sea ice extent. From now on, the sea ice increases, on average. The earliest minimum was August 25 in 1980 and the latest was September 24 in 2007. There is no real trend over time of when the minimum happens (perhaps a few days later).
http://img651.imageshack.us/img651/8171/nhsiemindateline.png
This chart compares the change in sea ice by day in 2011 versus the average change since 1972, as noted, 3 days in a row of increase now. While 2011 started the year with less ice, it more-or-less followed the average daily melt rate very closely. (I think the beginning sea ice extent in late March is the real determinant of how much ice there will be throughout the year – the average seasonal melt rate from the March Max to the Sept Min is very consistent increasing at just 0.1% per year since 1972).
http://img703.imageshack.us/img703/7779/nhsiedmrsept1211.png
Again, a “thank you” to Walt Meier for interacting with the public. As society becomes more connected and open it is essential to have the experts explain and work with those that are interested in their work. Scientists who refuse to do so and work to keep their work secret only breed skepticism of their integrity and further conspiracy theories. I do enjoy a good conspiracy theory though. : )
Deanster says:
September 13, 2011 at 7:17 am
Luther Wu … “icebreakers” …
Ya know .. I’ve always wondered what effect they have had on arctic ice
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Dean, it’s not the slush part……it’s breaking a huge seam all the way through it.
Just like when a floating end of a glacier, or any other floating sheet of ice breaks off.
That crack separates it and lets it drift away………….
a new record low has been met, declaring record minimum Arctic extent was reached on Sept 8 at 4.24 million km2
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This whole “science” is based on “average” “normal” “records” etc
…and the very people that claim it’s not normal, are allowed to define what is normal.
Different time frames, different measurements………all picked and chosen by the very people claiming it’s not normal.
Take that away from them, and whole science falls apart.
The less ice there is at the autumnal equinox, the less insulation there is on the Arctic Ocean when the long polar night falls, and the more the black ocean heat radiates into space. That sets the stage for more ice and colder polar currents next year.
Why do they continue to use a 1979 to 2000 Average?
Should we not be using a 1979-2010 Average on the graphs?
I am sure a 30 year aveage is more accurate and relevant than a 10 year old , 20 year average.
Basically, this all means nothing in the end. So we have a good 30 year account, but in the scheme of things it is still not enough to make any solid conclusions.
Thank you Walt Meier for commenting here and Thank you Anthony for a fine web site and forum.
Terry
Thanks to Mr. Walt Meier for his post — calm and factual, without cherry picking.
The scientific methods of the U. of Bremen in determining the “record” low extent may be perfectly legitimate. So why the compulsion to sully it with such an execrable and unscientific press release? Have they no shame?
Strange how the deviation has increased since 2007 in the Cryosphere anomaly plot. It looks like the instability has increase compared to previous years.
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.area.arctic.png
Even if (a big if) this seasons extent minimum barely avoids breaking `07s minimum, it`s still been a disastrous melt season for the Arctic. And if there was any old ice left at the beginning of the melt, it`s surely gone by now,,,or very close to being gone. I dread what next summer will do to the ice cap.
The Cryosphere graphs is the most telling. Whatever was happening post 1996 stopped in 2008 and we have been vacillating or hovering, awaiting a renewal or reversal since then. The analysis of what is likely to happen depends on understanding the slow drop to 1996 and then the sudden and sustained drop of ’96 – 2008.
Was the sudden drop the result of a thinning prior to ’96, with the thin ice suddenly breaking up or disappearing ’96 to 2008? If so, then are we seeing a consistent thinning of additional ice 2008 to 2011 that will suddenly disappear/break up and disappear now? I suspect the first and don’t suspect the second.
We will probably see a thickening of the main ice before we see an increase in extent: the first new ice will be thin and breakup easily, while extensions from thicker, more stable ice will take a year or two to show up, during which time the remaining ice will become thicker.
Prediction: thickening noted first, increase extent, later. Thickness in established, remaining areas is the key to watch.
“It seems to be clear that this is a further consequence of the man-made global warming with global consequences.”
I am not following the logic here. According to Lubos:
http://motls.blogspot.com/2011/09/rss-amsu-jan-aug-2011-second-coldest-in.html
“According to RSS AMSU, the first 8 months were the 2nd coldest January-August period in this century so far (second among 11 candidate years).”
Then how can the lowest or second lowest ice extent this year be blamed on global warming? As others have pointed out, there are other things that are more important than global warming here.
I’ll drink to that. Honey, are we out of ice for my scotch?