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TomC
New York
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Some interesting observations of note: 1. A large lead opened in the shorefast ice north of Siberia today, signaling the breakup of this feature. Although this will contribute to the daily reduction in SIA in the Laptev region, for a period of time SIE will increase or hold steady due to currents that will drift lower concentration ice over the polynya which currently exists there. 2. The North Atlantic drift in the area which meets the ice edge is a very dynamic region of the thermohaline circulation. For years it the north leg of this major current has been butt-up against Novaya Zemlya, creating that lobe of SIF waters to the northeast of the island. This extension of the current seems to have made a westward shift over the winter toward Franz Josef Land. 3. I'm no expert in this field but it appears the Jakobshavn glacier source region has retreated deeper into the GIS. I created this GIF showing the difference between 2009 and 2014.
@Susan Anderson The recent downturn is just a matter of happenstance. At this point in the refreeze season there's a natural bottleneck which occurs because there's a huge increase in landmass at the 70°N latitude band. During the first two weeks of November the biggest gain in sea-ice is usually in Baffin Bay, with the Chukchi/Bering and Barents/Kara typically averaging small daily gains but in reality this average is just a reflection of oscillation with a trajectory toward freeze-up due to winds from weather systems. Even more so, the sea-ice on the Atlantic side is quite variable due to the passage of storms along the ice edge, which extends much farther in distance than the ice edge in the Chukchi/Bering. Last week there was a period of extended southerly flow over the ice edge in the Barents/Kara Seas which more than offset the gains in Baffin Bay, with the Chukchi/Bering holding nearly steady. The end result was a week-long period of losses in extent/area, but since the temperatures along the ice edge on the Atlantic side were below freezing the likely result was a weeks' worth of compaction and a sea-surface skin temperature of -2°C in the once-ice-covered areas which should refreeze quickly. In fact, over the next ten days there's going to be dramatic increases in sea-ice extent due to three factors. 1. Days 5-10 features arctic air and northerly flow over the Barents/Kara Seas. This should basically freeze all of the Kara Sea but for a small donut hole in the southern end and drive the ice edge south 5-10nm/day each of those 6 days. 2. Very favorable freeze-up conditions across Hudson Bay. -20°C 850mb temps (arctic air) is fed over the western half of the basin on northwesterly flow for much of the next ten days. This should bring sea-ice over a third to a half of Hudson Bay by Thanksgiving. 3. The Chukchi should finish its refreeze and ice will begin developing in the Bering. These three factors, plus the continued freezing of Baffin Bay, should bring extent to about 10,600,000sq.km by Thanksgiving.
Toggle Commented Nov 17, 2013 on PIOMAS November 2013 at Arctic Sea Ice
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Nov 12, 2013