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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…clearly, the Arctic is in the throes of its death spiral!
Thanks, Anthony! It was a long fall & winter, checking the NSIDC site every day…glad this worked out!
I see they managed to stay on message with tales of gloom and doom despite the improved showing of extent. This one line is a prime example of the art of creative spin:
They don’t say so in as many words, but through the careful choice of words manage to suggest that this year’s low extent for March was only exceeded by the extent recorded in 20006. Yet a quick look at the years on display at the IARC-JAXA site reveal that this years extent was only significantly exceeded in 2003, while this year exceeded all years since. A rather different tale than that conveyed in their carefully crafted spin.
We’ll see how the ice does through the year. Personally, I’m looking for a showing close to the 6 m km² mark.
To Mr Watts and Contributing Authors,
Probably I am not the first commenter rising the question of the maps with the misleading colors used in nearly every climate issue presented here on WUWT weblog.
Why do use ***only*** anomaly maps without absolute counterparts?
For example. Fig.5 shows ***warm*** over the Arctic but if the average temperature over the area in the presented time period were -10 deg then the whole region would be in the grip of small but ***still*** freezing temperatures. Casual look at such absolute map would give me and others more than the true picture of the ice-melting-or-not issue.
Use the PsyOps techniques 🙂 (or popular science approach) to show WUWT readers that we are ***realists*** as far as the “climate change” issue is concerned.
Thank you.
Best regards
Przemysław Pawełczyk
REPLY: This entire post was the NSIDC Sea Ice News, reposted here. Complain to them about the visuals.
“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.”
Is it just me, or does the lower plot in Fig 6 not contradict this statement?
Looks like the boundary of the green area (>2 years old) ends up lower than every other year except 2009.
Mr Moderator,
You irked me a lot. I was not writing about this one post but the prevailing attitude.
I wasn’t complaining – I was suggesting. My remarks were not to stick a thorn in your… back but to make the blog better. Decidedly for me, I can speak only for myself.
Regards
Reply: I believe Anthony responded to you. ~ ctm
And here’s the Northern Hemispheric ice coverage map as of
6 April from Environment Canada in black and white:
http://www.weatheroffice.gc.ca/data/analysis/350_50.gif
Leon Brozyna, it’s a question of mindset: is your tumbler of, let’s say… whisky on the rocks, half full or half empty?
And as we well know: ‘The spin doctors of climatology
Deny any bias in their sea ice methodology.’
Was the arctic ice cap “Adjusted” ?
http://www.americanthinker.com/2010/04/was_the_arctic_ice_cap_adjuste.html
Death Spiral for Warmists!
http://eureferendum.blogspot.com/2010/04/death-spiral-for-warmists.html
Putting a price on melting icecaps!
http://www.time.com/time/business/article/0,8599,1977563,00.html
[snip, as you guessed. ~ ctm] Mr Unpronouncable. Check the source.
I know snip.
That line mathematically is linear not a seasonal or a parabolic as a sinusoidal would be, in a fluctuating series.
That curve actually is what one calls abnormal for a sinusoidal.
The words are talk.
Fluctuating 3 d series.
The map may be 2 D but the event is 3 D.
Is it just me or do the September 09/March 10 plots in Fig 6 make no sense.
If there was 1-2 year ice or older present in September 2009 at the end of the melt, how can the same area only have ice < 1 yr old in March 2010?
Also how can the area near Alaska be open ocean in September 09 but have 1-2yr and multi yr ice in March 10?
Long time lurker, first time poster – Great site.
at least.
It would be very interesting to see the salinity levels from year to year.
The temperature was warmer and the Sea Ice grew much greater.
The other anomally is that the pressure systems this winter stayed for very long periods of time. This would be much calmer winds that would allow more Ice growth without winds breaking them up with waves.
NSIDC say “Meanwhile, temperatures over the central Arctic Ocean remained above normal and the winter ice cover remained young and thin compared to earlier years.“.
Obviously it is remarkable that the ice remained young. Can ice get years older in a few months?
They appear to answer this question later on: “this winter has seen some replenishment …] However, this replenishment consists primarily of younger, two- to three-year-old multiyear ice; the oldest, and thickest multiyear ice has continued to decline.“.
That looks to me like a “yes”.
The AMRE plot shows sea-ice extent now greater than all years back to 2002.
Is there older data to say when the last year was that ice extent was greater??
Can someone explain to me why NSIDC say the ice age/quality is still poor, when this site was showing lots of diagrams showing ice quality far superior to recent times?
Request for enlightenment, not a demand for blame….
@ur momisugly yamaka
Ocean ice in the Arctic floats freely on the surface of the ocean, and it can be pushed around by the winds. Also, please note that the ice you see in NSIDC graphs is not swathes of solid ice – it’s “area of ocean with at least 15% ice.”
@ur momisuglyPrzemysław Pawełczyk
If you want to establish whether or not a given area is warming over time (which is an important element of the AGW debate) what better way to do it than present current temperatures as deviations from long-term mean (anomalies)?
Now this I will say that curve part is one of two things.
We have a behavior in a multivariable systems of forces that just went linear or asymptotic at some level, at n dimensional level.
Or we got friggen in the riggen with datasets.
My best guess friggen in the riggen, thats an R1 fit on a sinsusoidal curve.
Yer it’s the butler wot done it playing catch up covering his tracks..
yamaka (02:58:43) :
That’s older ice which has been dragged clockwise by the Beaufort gyre. That circulation has been stronger than in recent years because of the mainly negative Arctic Oscillation since October – it tends to keep ice and colder water circulating in the Arctic instead of flushing it out into the Atlantic.
I always wanted to use asomptopical in conversation.
But it’s a word you just dont get to use in polite company.
Not like fraud.
I’m with yamaka. The method to determine multi-year ice needs to be looked at if ice didn’t exist in an area in 2009 and is multi-year 6 months later or was multi-year at the end of the melt and becomes new ice at the end of the freeze. I realize that the ice is in motion and what was in one spot may very well have rotated to a new location, but these pictures just make me question the quality control of the thickness estimations.
More ice, same old spin, “Meanwhile, temperatures over the central Arctic Ocean remained above normal and the winter ice cover remained young and thin compared to earlier years.”
The Arctic Ocean could remain completely frozen year around and NSIDC would still find signs of sea ice decline…
“Cold weather” caused late melt, but “warm climate” caused 2007 low.
Place your bets for summer minimum.