Better late than never, here's NSIDC's latest analysis for the month of May. Most things are known to most of us, but I find the bolded excerpts towards the end very interesting:
Arctic sea ice extent for May 2012 averaged 13.13 million square kilometers (5.07 million square miles). This was 480,000 square kilometers (185,000 square miles) below the 1979 to 2000 average extent. This May’s extent was similar to the May 2008 – 2010 extent, but it was higher than May 2011. May ice extent was 550,000 square kilometers (212,000 square miles) above the record low for the month, which happened in the year 2004.
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Air temperatures for May were higher than usual over the central Arctic Ocean and the Canadian Archipelago. Over the Bering Sea, Hudson Bay, and parts of the East Greenland and Norwegian seas, temperatures were slightly below average.
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A persistent pattern of extensive ice in the Bering Sea
Continuing the pattern of the past six months, ice cover remained unusually extensive in the Bering Sea. Normally by the end of May, the Bering is largely ice-free, but this year, 350,000 square kilometers (135,000 square miles) of ice remained. As was also the case for February through April, May 2012 had the highest average Bering Sea ice extent for the month in the satellite record.
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Open water areas within the Arctic Ocean
Although ice extent has remained high in the Bering Sea, open water areas have developed in parts of the Arctic Ocean, notably along the coasts of the Beaufort and Laptev seas. These openings are largely driven by winds pushing the ice away from fast ice, ice that is attached to the coast and that does not move with the winds. That the open water areas have not refrozen points to the relatively warm conditions over the Arctic, particularly in the Beaufort Sea.
The ice cover in the southern Beaufort Sea is also substantially broken up, with many individual ice floes instead of a consolidated pack. This makes the ice in this region vulnerable to enhanced melt during summer, as the sun rises higher in the sky and the dark open water areas between the floes readily absorb solar energy.
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Quicker thickness data from NASA IceBridge
As we discussed last month, thickness information is extremely important for understanding the state of the ice cover. It is particularly important to seasonal forecasts (such as the SEARCH Sea Ice Outlook that will be released later this month), because thinner ice is more likely to melt completely during summer.
Sea ice age can be inferred from satellite data, and can help indicate the locations of relatively thin versus relatively thick ice. But direct measurements of ice thickness have been limited. Satellite missions such as ICESat and CryoSat, which measure ice thickness with altimeters, have been extremely valuable in better understanding overall changes in Arctic sea ice volume.
Currently, the NASA IceBridge mission supplies both sea ice thickness and snow depth measurements in spring, providing timely information on the state of the ice cover as the melt season begins. IceBridge data are collected from aircraft that fly over the ice cover carrying a suite of instruments, including altimeters that can directly measure ice thickness above the surface. These measurements are at high spatial resolution that can also be used to validate satellite data.
This year, the IceBridge Arctic sea ice campaign collected data in late March and early April, and provided data to NSIDC for distribution shortly thereafter. The data, collected from the North American side of the Arctic, indicate thick ice north of Greenland due to wind and ocean current patterns piling ice into thick ridges. In the Beaufort Sea, the offshore ice is fairly thin (1 to 2 meters, or 3 to 6 feet), indicative of first-year ice. Such thin ice will be prone to melt out completely this summer.
That last image might look familiar to you, as it resembles the one in this blog post from a few weeks back, where commenter 'deconstruct' constructed a map that shows ice thickness along the late March/early April flight paths of the planes of the IceBridge mission.
Read the whole NSIDC analysis here. Diablobanquisa has a commentary (in Spanish).
Neven,
When you develop your Algae/Phytoplankton bloom post, the past articles I've read were that the Arctic as opening up, would not contribute to CO2 uptake. Whilst I'm not too concerned about albedo effect, it's more of an ecosystem upset possibility. What generates oxygen, what dies and sinks and rots to methane, particular the shallower regions... add to that the run-off nutrients from land... even what get's carried in by the ocean currents, HSS contributed. The under-ice bloom was no surprise... seen documentaries years and years ago, MYI having rich bottom cultures. Thinning ice, more light and you've got your recipe.
-- Rob
Posted by: Seke Rob | June 10, 2012 at 12:48
I suggest that it is more than just "thinner ice". Frost and snow on the upper surface of the ice has melted, so that much more light is passing through ice of any given thickness.
Permafrost melting the last few years has resulted slough and slump events that have filled Arctic rivers with nutrients.
Failure to find large blooms would have been a surprise. What I find very interesting is no mention of zoo plankton and krill. The lack of copepods is more of a surprise than the presence of algae.
Posted by: Aaron Lewis | June 10, 2012 at 18:07
There was another huge drop in CT SIA yesterday: 286k km2. That's the second double-century decrease so far this year, and, in fact, it's a larger one-day decrease than any that occurred in all of 2011. In just the past three days, SIA has fallen a whopping 590k km2.
SIA stands this morning at 9.07 million km2. That keeps 2012 in first place, with more than 100k km2 less ice than there was in second-place 2010.
Posted by: Jim_pettit | June 11, 2012 at 14:14
It took AIL and Jim a little less time to get to grasps with the new data. IJIS does almost 90K km2 a day in june on extent, CT 100K on area. Not compaction, plain melt Bering, Baffin, Hudson Barentsz, Kara and Laptev. It could easily continue on this pace right into July.
The config shows rapid ice movement from Sib to the CAA for the next three days, to make things worse.
Posted by: Werther | June 11, 2012 at 14:29
Jim, I believe the drop was 266K. Still pretty decent. ;-)
Posted by: Neven | June 11, 2012 at 18:52
Neven, you are correct. I mistyped, then couldn't make the required edit. Guess I'll be sure to triple preview next time, as two times wasn't enough. ;-)
Posted by: Jim_pettit | June 11, 2012 at 19:39
Part of that drop may go away on tomorrow's report. There is a section of the SSMIS pass in the Labrador Sea that was not included in the 10 June data.
On the other hand - it is 35 C or 95 F currently at the southern section of the Hudson Bay.
Eureka, Canada is to remain above freezing for the next 10 days, including a high of 11 C on Thursday with rain.
Tiksi, Russia remains above freezing with forecasted highs close to 20 C with rain at least once in the next 10 days.
Both sides of the Arctic are getting torched and the ice melt seems to be set to remain high.
Posted by: Apocalypse4Real | June 11, 2012 at 22:41
Another big drop in the CT area measure. Air temps, cloud cover and ice distribution *appear* favorable for a continuation of this trend for a few days.
Posted by: Greg Wellman | June 12, 2012 at 22:24