From NSIDC Sea Ice News:
Cold snap causes late-season growth spurt
Arctic sea ice reached its maximum extent for the year on March 31 at 15.25 million square kilometers (5.89 million square miles). This was the latest date for the maximum Arctic sea ice extent since the start of the satellite record in 1979.
Early in March, Arctic sea ice appeared to reach a maximum extent. However, after a short decline, the ice continued to grow. By the end of March, total extent approached 1979 to 2000 average levels for this time of year. The late-season growth was driven mainly by cold weather and winds from the north over the Bering and Barents Seas. Meanwhile, temperatures over the central Arctic Ocean remained above normal and the winter ice cover remained young and thin compared to earlier years.
Figure 1. Arctic sea ice extent for March 2010 was 15.10 million square kilometers (5.83 million square miles). The magenta line shows the 1979 to 2000 median extent for that month. The black cross indicates the geographic North Pole. Sea Ice Index data. About the data.
—Credit: National Snow and Ice Data Center
Overview of conditions
Arctic sea ice extent averaged for March 2010 was 15.10 million square kilometers (5.83 million square miles). This was 650,000 square kilometers (250,000 square miles) below the 1979 to 2000 average for March, but 670,000 square kilometers (260,000 square miles) above the record low for the month, which occurred in March 2006.
Ice extent was above normal in the Bering Sea and Baltic Sea, but remained below normal over much of the Atlantic sector of the Arctic, including the Baffin Bay, and the Canadian Maritime Provinces seaboard. Extent in other regions was near average.
Figure 2. The graph above shows daily sea ice extent as of April 4, 2010. The solid light blue line indicates 2010; green shows 2007; dark blue indicates 1999, the year with the previous latest maximum extent, which occurred on March 29, 1999; and solid gray indicates average extent from 1979 to 2000. The gray area around the average line shows the two standard deviation range of the data. Sea Ice Index data.
—Credit: National Snow and Ice Data Center
Conditions in context
Sea ice reached its maximum extent for the year on March 31, the latest maximum date in the satellite record. The previous latest date was on March 29, 1999. The maximum extent was 15.25 million square kilometers (5.89 million square miles). This was 670,000 square kilometers (260,000 square miles) above the record low maximum extent, which occurred in 2006.
Sea ice extent seemed to reach a maximum during the early part of the month, but after a brief decline, ice extent increased slowly and steadily through the end of the month. By the end of the month, extent had approached the 1979 to 2000 average. During March 2010, ice extent grew at an average of 13,200 square kilometers (5100 square miles) per day. Usually there is a net loss of ice through the month.
Figure 3. Monthly March ice extent for 1979 to 2010 shows a decline of 2.6% per decade.
—Credit: National Snow and Ice Data Center
March 2010 compared to past yearsThe average ice extent for March 2010 was 670,000 square kilometers (260,000 square miles) higher than the record low for March, observed in 2006. The linear rate of decline for March over the 1978 to 2010 period is 2.6% per decade.
Figure 4. The map of sea level pressure (in millibars) for March 2010 shows high pressure over the central Arctic (areas in yellow and orange) and areas of low pressure over the Bering and Barents seas (areas in blue and purple). The low pressure systems over the Bering and Barents seas have helped to push the ice edge southward.
—Credit: National Snow and Ice Data Center courtesy NOAA/ESRL Physical Sciences Division
Late-season growth spurt
The maximum Arctic sea ice extent may occur as early as mid-February to as late as the last week of March. As sea ice extent approaches the seasonal maximum, extent can vary quite a bit from day to day because the thin, new ice at the edge of the pack is sensitive to local wind and temperature patterns. This March, low atmospheric pressure systems persisted over the Gulf of Alaska and north of Scandinavia. These pressure patterns led to unusually cold conditions and persistent northerly winds in the Bering and Barents Seas, which pushed the ice edge southward in these two regions.
Figure 5. This map of air temperature anomalies for March 2010, at the 925 millibar level (roughly 1,000 meters or 3,000 feet above the surface), shows warmer than usual temperatures over most of the Arctic Ocean, but colder than usual temperatures in the Bering and Barents seas, where sea ice extent is above normal. Areas in orange and red correspond to positive (warm) anomalies. Areas in blue and purple correspond to negative (cool) anomalies.
—Credit: National Snow and Ice Data Center courtesy NOAA/ESRL Physical Sciences Division
Meanwhile, elsewhere in the Arctic
This winter’s strong negative mode of the Arctic Oscillation was moderated through the month of March. Average air temperatures for the month nevertheless remained above average over the Arctic Ocean region. Overall for the winter, temperatures over most of the Arctic were above average, while northern Europe and Siberia were colder than usual.
Figure 6. These images show the change in ice age from fall 2009 to spring 2010. The negative Arctic Oscillation this winter slowed the export of older ice out of the Arctic. As a result, the percentage of ice older than two years was greater at the end of March 2010 than over the past few years.
—Credit: National Snow and Ice Data Center courtesy J. Maslanik and C. Fowler, CU Boulder
Ice age and thickness
The late date of the maximum extent, though of special interest this year, is unlikely to have an impact on summer ice extent. The ice that formed late in the season is thin, and will melt quickly when temperatures rise.
Scientists often use ice age data as a way to infer ice thickness—one of the most important factors influencing end-of-summer ice extent. Although the Arctic has much less thick, multiyear ice than it did during the 1980s and 1990s, this winter has seen some replenishment: the Arctic lost less ice the past two summers compared to 2007, and the strong negative Arctic Oscillation this winter prevented as much ice from moving out of the Arctic. The larger amount of multiyear ice could help more ice to survive the summer melt season. However, this replenishment consists primarily of younger, two- to three-year-old multiyear ice; the oldest, and thickest multiyear ice has continued to decline. Although thickness plays an important role in ice melt, summer ice conditions will also depend strongly on weather patterns through the melt season.
At the moment there are no Arctic-wide satellite measurements of ice thickness, because of the end of the NASA Ice, Cloud, and Land Elevation Satellite (ICESat) mission last October. NASA has mounted an airborne sensor campaign called IceBridge to fill this observational gap.
More Information
For more information, including animations and satellite images, visit the NASA Arctic 2010 Sea Ice Maximum Web page.
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NSIDC: “The negative Arctic Oscillation this winter slowed the export of older ice out of the Arctic. As a result, the percentage of ice older than two years was greater at the end of March 2010 than over the past few years.”
I would have given honorable mention to the recovery in the young ice since a couple years ago and the related recovery in the 1-2 yr old ice last year. I might have even called it remarkable. I wouldn’t have given full credit to the more ephemeral negative AO.
Clearly I’m not cut out to work at the NSIDC. There’s a good chance next year will have a further increase in the 2 year old ice, perhaps I’ll spend the next year looking for some anomaly to excuse further recovery.
Yamaka
Remember that this is Arctic sea ice, and so is floating. It moves in response to wind and current (which was largely responsible for the extremely low mimimum value in summer 2007).
A couple of interesting points:
1) This winter has been relatively warm in the Arctic, yet has seen more ice accumulation than several other recent years, and with a very late maximum – shows that there are other factors than temperature to consider (wind and current, precipitation, local conditions in different basins)
2) The extent based on both 15% and 30% sea ice is running close to long term average, suggesting that the high extent is not limited to very fragmented and thin ice, but to significant accumulation.
However, there seems to be poor correlation between maxima and minima – the extent at peak melting always seems to be tightly bounded. Perhaps someone with more time and knowledge on this subject could take a look at how the ice margins during rapid melting (and freezing) match with isotherms during these periods.
Przemysław Pawełczyk (01:00:12) :
You’re not the first, and not all graphics/maps display anomalies.
Maps with absolute temperatures have their place, but once you figure out there’s a 50K difference between the cold and warm areas in the region shown on the maps above, that all becomes background knowledge and not very interesting in discussing longer term ice cover changes.
One source of maps with absolute temps is http://wxmaps.org/pix/clim.html, but they don’t reach the poles. http://wxmaps.org/pix/hemi.fcst.html does reach the north pole, but only at 850 mb, and the graphs are very “busy” and tough to read.
Perhaps you could contact the NSIDC and ask that they produce a series of maps of average temperatures for the covered region for each month of the year. Ask for maps that cover the satellite record (those cover the warm PDO phase) and also for the last 10 years (to cover the peak PDO-influenced temperatures).
This of course is weather.
Yamaka:
The wind driven ice changes the location and area covered even during ice growth seasons. Wind driven compaction will give the appearance of ice loss. OTOH the wind can also spread the ice to cover more area. These figures represent locations with more than either 15% or 30% depending on who is guessing the amount of ice. Claims of either greater or lesser in recorded history are equal to exaggeration /bias. I will say thank you for this example of the spin NSIDC and other government groups put on weather issues to justify their existence. One day they will learn there is only so far over the reality line they can cross before they make their positions valueless.
How are we coming on tourist boat rides in the Northwest passage?
Did they refund the tickets?
Oh noo dios mio que pasa?
http://ocean.dmi.dk/arctic/icecover.uk.php
Where is the discussion on reflectivity with a larger sea ice area no matter what the thickness?
It’s shocking and sad to see Serreze gradually go from scientist in 1992 and finding “no evidence of global warming” to manmade warming True Believer in 2009 and his statement “you are probably looking at ice-free summers by 2030. I’d call that a death spiral”.
By 2030 the whole manmade global warming/climate change hysteria will be a distant memory of a nightmarish time in human history, when reason, rationality, and science were thrown out the window, and those attempting to restore them were reviled, disparaged, and threatened. Mankind will be seen to have gone slightly mad, and children will study it in history books and marvel at the level of stupidity, avarice, and self-aggrandizement of so-called “climate scientists”, and the despicable actions of NGOs, politicians, the MSM, and assorted carpetbaggers seeking to capitalize from it.
I don’t have problems with anomaly maps, even if they do ‘look bad’. But this last point is the issue – they *look* bad.
From that standpoint, they are abused: they are presented to the layman (a person who has no background knowledge) and the extreme elements are highlighted, in text and pictures, and disingenuously ‘correlated’ to unrelated occurrences.
The problem isn’t with the anomaly mapping/charting but with the education and understanding of the average person to whom the information is being presented to.
I believe, today, we are less educated than we were in the past. This is a world-wide phenomenon (of course, I’m committing the sin of extrapolation from what I observe in both the US and the UK).
There is an expanding gray area where facts, theories, causality, politics and ideology are intermixed and interchanged – the uninitiated and undereducated cannot distinguish these effects for what they really are.
From what all the global warming crowd was telling us I thought all the ice was supposed to be gone by now. If it is so warm why has the ice grown?
About the claim that Arctic temperatures are above normal–how many temperature sensors do they have and how far apart are they? How much extrapolation goes into that statement? It comes from NOAA. Is it related to the temperature map that appears to be based on a handful of data points extrapolated across thousands of square kilometers? Just asking.
At the moment there are no Arctic-wide satellite measurements of ice thickness, because of the end of the NASA Ice, Cloud, and Land Elevation Satellite (ICESat) mission last October.
Thus they are admitting their guessing is worse than before?
…and the winter ice cover remained young and thin compared to earlier years.
So the ice has gone from rotten to raw.
Thus the Arctic is healing up, but it really should put on a bandage over the bad spot.
Thanks, Stephan (05:23:03), for showing us the present ice extent. Now will this make the cable news? Maybe on Fox but definitely not on MSNBC nor CNN. Do you suppose we need to contact NSIDC to let them know of the sea ice extent? They probably already know this, so how they will spin this one? I KNOW, I KNOW, GLOBAL WARMING.
Note that their March average includes a lot bigger difference between the statistical average and the current average than the April data is likely to show, in which case their report in May should show a big uptick.
Stephan (05:23:03) :
“Oh noo dios mio que pasa?
http://ocean.dmi.dk/arctic/icecover.uk.php ”
The chart Stephan refers to, looks a lot clearer.
It also explains the info.
Przemysław Pawełczyk take a look.
I must say I was pleasantly surprised with the almost neutral, (with respect to AGW,) tone of the report. May this trend continue into the future.
I loved the part where they said “However, this replenishment consists primarily of younger, two- to three-year-old multiyear ice; the oldest, and thickest multiyear ice has continued to decline.”
Last year the ice was no good because it was made up primarily of that nasty, rotten, 1 – 2 year old ice. Next year they will be lamenting all of that unreliable 3 – 4 year old ice. I wonder how long they think they can keep milking this?
Ok, I have a really stupid question – but it’s bugging me so I got to ask.
That last image compares ice from September 2009 – when ice extent starts growing – with ice in April 2010 – when the ice extent starts shrinking, right?
How come there is more 2nd and 3rd year ice at the start of the growing season than at the end of it? How was it that much of that 2nd and 3rd year ice managed to disappear at the same time that fresh new ice was appearing?
My best guess would be that winds and currents combined to compress that older ice so making at appear that there was less of it at the end of the season than at the start – but if that were the case then the whole basis for measuring sea ice extent is pointless. Surely we ought to measure the overall mass of ice rather than just how far it extends?
To infer ice thickness based on age is a mistake. Ask anyone who lives on the shores of the wind blown Great Lakes. Ask anyone who has lost their river side house to an ice jam. Ask anyone who has crossed the bridge at the bottom of Chief Joseph grade during a long cold winter. Ice compaction is the key to thickness and slow melt, along with winds that are either weakly out to Fram Strait, or are blowing INTO Fram Strait. Maybe we should ask our Ice Reporters at NSICD to take a course in floating ice and wind mechanics in a confined bowl. Or better yet, have them rent a house on the edge of one of the windward sides of the Great Lakes during a cold winter. Bet they will not talk about thin one year ice ever after.
Eye of the Gyre
As I posted at Climate Progress – the Beaufort Gyre is back.
The Beaufort Gyre is a region almost the size of the Gulf of Mexico with a four-year clockwise spiral – speaking of spirals – in which ice remains trapped for long periods. The dramatic loss of sea ice in 2007 was predominantly in the region of the Beaufort Gyre.
http://nsidc.org/images/arcticseaicenews/20100406_Figure6.png
If you look at the multiyear ice map, you can see a significant plume of second year and older ice extending on the southern edge of the Beaufort Gyre all the way to northeast Siberia before wrapping around. Already, multiyear ice makes a 3/4s circle. Given that 2007 was a year of extreme ice loss, it seems that the Beaufort Gyre is well on its way to reestablishing older ice patterns. 2011 may see a complete loop of multiyear ice with ice in the interior relatively protected from summer melt. That could produce a dramatic increase in the Sept 2011 sea ice minimum.
In addition, NSIDC says that the new ice is “thin” –
Yet this map from Canadian Climate shows that first year ice in the Western Arctic is thick.
http://ice-glaces.ec.gc.ca/prods/WIS56SD/20100329180000_WIS56SD_0004895913.gif
One last note, the NSIDC map also shows open water in the Canadian Archipelago. That is a serious error – not only because the waters of the Northwest Passage are, most certainly, frozen in March – but also because significant amounts of multiyear ice are found in the channels among the Queen Elizabeth Islands.
No mention that ice extent has gone up during an El Nino year. If it weren’t for El Nino, how much more ice might there have been?
NSIDC’s latest analysis is an accurate accounting of exactly what occured in March 2010. Furthermore, their point about the warm conditions over the central arctic is also exactly right, and there is a large area of ice in this region that will show rapid melt when the full thrust of the melt season hits. I stand by my prediction of a 4.5 million sq. km. minimum sea ice extent for Sept. 2010 (as measured by IJIS/JAXA). Hudson Bay over to Greenland and then up into the central arctic has been very warm during the extreme negative AO of the winter and the ice will melt faster than normal in these regions.
So climate has NOT change. We still have more ice in the winter and less ice in the summer.
The passion to insert spin is so obvious for the warmist. It is an itch they can’t get rid of by scratching.
If the summer minimum in 2009 was larger than in 2008, why does the Sept 09 map show no ice less than one year old?