A previous post discussed 15M km2 as the average maximum threshold for March arctic ice extents.The graph shows 2019 exceeded the previous two years, but now it appears to fall just short. On day 61, March 2, 2016 peaked well above 15M, and did not reach that level again. The graph shows 2017 peaked early and then descended into the Spring melt. 2018 started much lower, gained steadily before peaking on day 74, 250k km2 below average. 2019 has been exceptional, surging early to surpass average on day 54, then declined for a week, before re-surging to virtually tie the average extent on day 70. Day 71 extent matched the earlier peak, then retreated and is now unlikely to go higher after day 75.
Presently, on day 75 2019 is 1% below the 12 year average (2007 to 2018 inclusive) and slightly higher than the preceding three years.
As reported previously, the action is mostly in the Pacific basins. The last 10 days show Bering on the right recovering from its minimum to add back 230k km2. Meanwhile Okhotsk on the left lost 120k km2, so the combined gain was not enough for NH to reach the threshold. On the Atlantic side, ice extents held firm, with Barents higher than in recent years.
Note on the left the ice has pushed well south of Newfoundland. On the right Barents ice is holding onto Svalbard, and Kara remains at its maximum.
The table below shows the distribution of ice over the various Arctic basins compared to average and to last year.
Region | 2019075 | Day 075 Average |
2019-Ave. | 2018075 | 2019-2018 |
(0) Northern_Hemisphere | 14823898 | 14996207 | -172310 | 14704038 | 119860 |
(1) Beaufort_Sea | 1070498 | 1070200 | 297 | 1070445 | 53 |
(2) Chukchi_Sea | 965766 | 966002 | -236 | 966006 | -240 |
(3) East_Siberian_Sea | 1087137 | 1087134 | 3 | 1087137 | 0 |
(4) Laptev_Sea | 897845 | 897842 | 3 | 897845 | 0 |
(5) Kara_Sea | 934746 | 917400 | 17346 | 934970 | -224 |
(6) Barents_Sea | 777137 | 618675 | 158462 | 718542 | 58595 |
(7) Greenland_Sea | 549834 | 616633 | -66799 | 533408 | 16426 |
(8) Baffin_Bay_Gulf_of_St._Lawrence | 1561378 | 1593403 | -32025 | 1480294 | 81084 |
(9) Canadian_Archipelago | 853337 | 852783 | 555 | 853109 | 229 |
(10) Hudson_Bay | 1260903 | 1257469 | 3434 | 1260838 | 66 |
(11) Central_Arctic | 3235099 | 3218575 | 16524 | 3167361 | 67738 |
(12) Bering_Sea | 371625 | 802103 | -430478 | 432417 | -60791 |
(13) Baltic_Sea | 54792 | 82770 | -27978 | 125618 | -70826 |
(14) Sea_of_Okhotsk | 1194159 | 995230 | 198928 | 1159963 | 34196 |
The table shows that except for Bering, Arctic ice extents are firm almost everywhere. Barents, Kara and Okhotsk are well above average, but not enough to offset the deficit of Bering ice, even with the recent recovery.
Typically, Arctic ice extent loses 67 to 70% of the March maximum by mid September, before recovering the ice in building toward the next March.

Drift ice in Okhotsk Sea at sunrise.
Reblogged this on Climate Collections.
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