Arctic Ice Hockey Stick Reappears August End

 

Firstly note that on average August shows ice declining 1.94M km2 down to 4.91M km2. But 2022 started higher and on day 238 was approaching average, before ceasing further ice losses (see HS blade above).  As a result the 2022 August ice extent decline is only 1.54m km2.  The extents in Sea Ice Index in orange  were somewhat lower during the period. The table for day 243 shows a 10% 2022 surplus over average and how the ice is distributed across the various seas comprising the Arctic Ocean.   The surplus this year over 2020 is more than 1 Wadham (1M km2 ice extent).

Region 2022243 Day 243 Average 2022-Ave. 2020243 2022-2020
 (0) Northern_Hemisphere 5423812 4937670 486142 4345398 1078414
 (1) Beaufort_Sea 765946 581575 184371 763281 2665
 (2) Chukchi_Sea 337051 263324 73727 212438 124613
 (3) East_Siberian_Sea 464187 360036 104151 176996 287191
 (4) Laptev_Sea 209309 158411 50898 1029 208279
 (5) Kara_Sea 23665 49416 -25751 23958 -293
 (6) Barents_Sea 0 18330 -18330 0 0
 (7) Greenland_Sea 216732 167036 49696 192361 24370
 (8) Baffin_Bay_Gulf_of_St._Lawrence 38231 25602 12628 5016 33215
 (9) Canadian_Archipelago 301559 311236 -9677 273116 28443
 (10) Hudson_Bay 2870 23416 -20545 23611 -20740
 (11) Central_Arctic 3064128 2978402 85726 2672904 391224

There are only a few small deficits to average overcome by surpluses almost everywhere, especially in BCE (Beaufort, Chukchi, East Siberian seas), as well as Central Arctic, Laptev and Greenland Sea.  And as discussed below, the marginal basins have little ice left to lose.

The Bigger Picture 

The annual competition between ice and water in the Arctic ocean is approaching the maximum for water, which typically occurs mid September.  After that, diminishing energy from the slowly setting sun allows oceanic cooling causing ice to regenerate. Those interested in the dynamics of Arctic sea ice can read numerous posts here.  This post provides a look at  August from 2007 to yesterday as a context for anticipating this year’s annual minimum.  Note that for climate purposes the annual minimum is measured by the September monthly average ice extent, since the daily extents vary and will go briefly lowest on or about day 260.

The large August surplus in 2022 is significant:  In a typical year the overall ice extent will end September slightly higher than at the beginning.

We are close to the annual Arctic ice extent minimum, which typically occurs on or about day 260 (mid September). Some take any year’s slightly lower minimum as proof that Arctic ice is dying, but the image above shows the Arctic heart is beating clear and strong.

Over this decade, the Arctic ice minimum has not declined, but since 2007 looks like fluctuations around a plateau. By mid-September, all the peripheral seas have turned to water, and the residual ice shows up in a few places. The table below indicates where we can expect to find ice this September. Numbers are area units of Mkm2 (millions of square kilometers).

Day 260 15 year
Arctic Regions 2007 2010 2014 2015 2016 2017 2018 2019 2020 2021 Average
Central Arctic Sea 2.67 3.16 2.98 2.93 2.92 3.07 2.91 2.97 2.50 2.95 2.90
BCE 0.50 1.08 1.38 0.89 0.52 0.84 1.16 0.46 0.65 1.55 0.89
LKB 0.29 0.24 0.19 0.05 0.28 0.26 0.02 0.11 0.01 0.13 0.15
Greenland & CAA 0.56 0.41 0.55 0.46 0.45 0.52 0.41 0.36 0.59 0.50 0.47
B&H Bays 0.03 0.03 0.02 0.10 0.03 0.07 0.05 0.01 0.02 0.04 0.03
NH Total 4.05 4.91 5.13 4.44 4.20 4.76 4.56 3.91 3.77 5.17 4.44

The table includes two early years of note along with the last 8 years compared to the 15 year average for five contiguous arctic regions. BCE (Beaufort, Chukchi and East Siberian) on the Asian side are quite variable as the largest source of ice other than the Central Arctic itself.   Greenland Sea and CAA (Canadian Arctic Archipelago) together hold almost 0.5M km2 of ice at annual minimum, fairly consistently.  LKB are the European seas of Laptev, Kara and Barents, a smaller source of ice, but a difference maker some years, as Laptev was in 2016.  Baffin and Hudson Bays are inconsequential as of day 260.

For context, note that the average maximum has been 15M, so on average the extent shrinks to 30% of the March high before growing back the following winter.  In this context, it is foolhardy to project any summer minimum forward to proclaim the end of Arctic ice.

Resources:  Climate Compilation II Arctic Sea Ice

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