Last month came breathless headlines from Inside Climate News: Alaska’s Bering Sea Lost a Third of Its Ice in Just 8 Days
The good news was that the ice was found just next door in Okhotsk Sea. As the image above showed, Bering did reduce its coverage, but Okhotsk was gaining at the same time. Over those 12 days, Bearing lost 173k km2 of ice extent while Okhotsk gained 185k km2.
Now we have perhaps already passed the annual maximum, which on average was 15.1M km2 on day 62.
2018 has reduced ice extent the last three days since peaking on day 63. It came near to 2007 and 2016 before retreating. And as in the past, SII is tracking about 200k km2 lower. The regional extents are shown in the table below.
The 2018 deficit to average is almost entirely due to Bering Sea lack of refreezing, now 525k km2 below recent normal. On the European side, Barents and Kara are nearly average, with Greenland Sea down about 20%. It remains to be seen if this year’s maximum is past or if more extent is gained in the coming week.
The graph below shows 2018 NH ice extents since day 1, with and without the Pacific basins Bering and Okhotsk, compared to 11 year averages (2007 to 2017 inclusive).
The deficit comes mostly from Bering Sea, while Okhotsk is above average, and Barents has grown recently. Greenland Sea and Central Arctic are down to a lesser extent, nearly offset by Baffin surpluses. A month remains to reach annual maximum with the standard this decade being about 15M km2. For perspective, 2018 has to gain about 6% by mid March to reach 15M and gain 4% to reach 14.78, last year’s maximum. It should also be remembered that all of these dancing basins will likely melt out by September as usual.
For a more comprehensive report see Feb. Arctic Ice Dance
via Science Matters
March 8, 2018 at 01:03PM