
Meltponds and leads in the Arctic ice cap show evidence of refreezing
Day 315, November 11, 2015 produced several milestones for Arctic ice recovery. 2015 extent virtually caught up to 2014 for that same day. For the first time since July 1, ice extent is again 10M km2. MASIE shows 10.1M compared to NOAA at 9.7M. This is the home stretch since annual averages in the last decade range between 10 to 11 M km2.
2015 has gained steadily averaging a daily rate of 107k km2. As a result, this year and last are virtually tied at this point.
The BCE region (Beaufort, Chukchi, East Siberian) is now 103% of 2014 at this date, with Beaufort completely frozen and East Siberian nearly so. Most seas exceed 2014 at this date. The largest remaining differences are Barents and Kara, which melted early and have not yet recovered. CAA has recovered after the August 2015 storm and now matches last year, through the Central Arctic still lags behind. Those shortfalls are offset by much greater ice extents in Baffin and Hudson Bays.
From MASIE
Ice Extents | 2014315 | 2015315 | Ice Extent |
Region | km2 Diff. | ||
(0) Northern_Hemisphere | 10077460 | 10055179 | -22281 |
(1) Beaufort_Sea | 1070445 | 1070445 | 0 |
(2) Chukchi_Sea | 609398 | 610670 | 1272 |
(3) East_Siberian_Sea | 970647 | 1045269 | 74622 |
(4) Laptev_Sea | 897845 | 897757 | -88 |
(5) Kara_Sea | 817367 | 715936 | -101431 |
(6) Barents_Sea | 397719 | 87660 | -310059 |
(7) Greenland_Sea | 524605 | 527729 | 3124 |
(8) Baffin_Bay_Gulf_of_St._Lawrence | 397085 | 702650 | 305566 |
(9) Canadian_Archipelago | 853214 | 852724 | -490 |
(10) Hudson_Bay | 250550 | 339763 | 89214 |
(11) Central_Arctic | 3236108 | 3185406 | -50703 |
The comparison with 2014 informs us whether this year will “bend the trend” of recovering ice extent since 2007, and by how much. The pace of refreezing this year is impressive and the end result remains to be seen. It seems unlikely that the previous two years annual averages can be overtaken this late in the calendar.
Summary
My guess: 2015 Average Annual extent will finish as the 3rd highest in the last 10 years, ahead of the years before 2013.
Still a Bronze Medal is not bad for a year that started with a lower March maximum, had the Pacific Blob melt out Bering Sea a month early, saw a negative AO most of the summer ensuring higher insolation and melting, and finally underwent a strong storm late August when ice edges were most fragile.