March 2021 Arctic Ice Persists

March Arctic ice 2007 to 2021

Previous posts showed 2021 Arctic Ice fell short of breaking the 15M km2 ceiling mid March due to a February Polar Vortex disruption.  As we shall see below, another smaller PV disruption is now occurring accelerating the normal spring melting season.  The graph above shows that the March monthly average has varied little since 2007, typically around the SII average of 14.7 M km2.  Of course there are regional differences as described later on.

Dr. Judah Cohen at AER provides an image of how this latest PV disruption appears:

gfs_animation_010hpa_20210322_20210407

The High pressure areas were forecasted to warm over the Pacific Arctic basins, and extending over to the European side, while the cold Low area is presently extending down into North America, bringing some snow on April 1 in Montreal (no joke).  The effect on Arctic Ice is shown in the animation below:

ArcticMarch2021 080 to 090

Over the last 10 days, Okhotsk upper left lost 180k km2 whiile Bering lower left lost half that with a slight recovery yesterday.  Barents Sea upper right lost 145k km2 over the same period.  The effect on NH total ice extents is presented in the graph below.

Arctic2021090

The graph above shows ice extent through March comparing 2020 MASIE reports with the 14-year average, other recent years and with SII.  After drawing close to average by day 80, 2021 ice extents dropped sharply and at March end matched both 2020 and 2007.  Despite losses from this PV event, the 2020 March monthly average ended up comparable to other years, as seen in the chart at the top.  In fact, the SII dataset of monthly gains and losses shows March 2020 gained slightly over end of February, compared to an average 200k km2 loss for the average March.

 

The table below shows the distribution of sea ice across the Arctic regions.

Region 2021090 Day 090 Average 2021-Ave. 2007090 2021-2007
 (0) Northern_Hemisphere 14266634 14692014  -425380  14222916 43718 
 (1) Beaufort_Sea 1070689 1070177  512  1069711 978 
 (2) Chukchi_Sea 966006 964100  1907  966006
 (3) East_Siberian_Sea 1087137 1086134  1003  1074908 12229 
 (4) Laptev_Sea 897827 896838  989  884340 13487 
 (5) Kara_Sea 935023 916581  18442  892157 42866 
 (6) Barents_Sea 602392 649566  -47174  441970 160422 
 (7) Greenland_Sea 620574 658050  -37476  686312 -65739 
 (8) Baffin_Bay_Gulf_of_St._Lawrence 1243739 1438412  -194673  1217467 26272 
 (9) Canadian_Archipelago 854597 852959  1638  850127 4470 
 (10) Hudson_Bay 1260903 1254727  6176  1229995 30908 
 (11) Central_Arctic 3192844 3234463  -41619  3242237 -49393 
 (12) Bering_Sea 549939 736829  -186890  814788 -264849 
 (13) Baltic_Sea 33543 60874.18571 -27331  45897 -12354 
 (14) Sea_of_Okhotsk 942085 861234  80850  794657 147428 

Overall NH extent March 31 was below average by 425k km2, or 3%.  The bulk of the deficit is seen in Bering and Baffin, along with Barents Sea.  Okhotsk remains above average in spite of recent losses.  The onset of spring melt is as usual in most regions.

via Science Matters

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April 1, 2021 at 11:59AM

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