From Science Matters

By Ron Clutz

The animation above shows the minimum daily extent for 2023 occurred on September 25.  In the next six days ~450k km2 of ice extent was added (nearly half a Wadham). The Arctic ice extent yesterday was 4.53M km2 approaching the 17 year average for the day.

The graph for September shows the first two weeks 2023 was well below the average and tracking with 2007. After hitting bottom day 258, a sharp recovery lifted extents close to average and much higher than 2007.  (SII  has not yet posted a value for day 264).

Note that typically September ends the month slightly higher than it begins, though 2023 is already matching its Sept. 1 value.  If this year’s ice growth continued at the same rate of losses during the first two weeks of September (50k per day), the extent would reach  ~5M km2 at month end.  That would result in a 2023 September monthly average of 4.5M km2.  Such extent would be close to the median prediction, somewhat lower than 2022, but much higher than 2007 or 2020, and 800k km2 higher than 2012 (the year of the great August Cyclone.)

The table for day 264 shows how the ice extent is distributed across the Arctic regions, in comparison to 17 year average and 2007.

Region2023264264 Average2023-Ave.20072642023-2007 (0) Northern_Hemisphere45308624603044 -72183 4129308401554  (1) Beaufort_Sea353539514036 -160497 507235-153697  (2) Chukchi_Sea135936167774 -31839 30316105620  (3) East_Siberian_Sea48471262691 -214220 31148160  (4) Laptev_Sea381662127644 254018 223595158067  (5) Kara_Sea4398934853 9136 2795016038  (6) Barents_Sea239414654 -12260 4851-2457  (7) Greenland_Sea273632202253 71379 336388-62756  (8) Baffin_Bay_Gulf_of_St._Lawrence6685334768 32085 3173135122  (9) Canadian_Archipelago177101302976 -125875 237555-60454  (10) Hudson_Bay04119 -4119 2270-2270  (11) Central_Arctic30461452936249 109896 2725832320313

Region	2023264	264 Average	2023-Ave.	2007264	2023-2007
(0) Northern_Hemisphere	4530862	4603044	-72183	4129308	401554
(1) Beaufort_Sea	353539	514036	-160497	507235	-153697
(2) Chukchi_Sea	135936	167774	-31839	30316	105620
(3) East_Siberian_Sea	48471	262691	-214220	311	48160
(4) Laptev_Sea	381662	127644	254018	223595	158067
(5) Kara_Sea	43989	34853	9136	27950	16038
(6) Barents_Sea	2394	14654	-12260	4851	-2457
(7) Greenland_Sea	273632	202253	71379	336388	-62756
(8) Baffin_Bay_Gulf_of_St._Lawrence	66853	34768	32085	31731	35122
(9) Canadian_Archipelago	177101	302976	-125875	237555	-60454
(10) Hudson_Bay	0	4119	-4119	2270	-2270
(11) Central_Arctic	3046145	2936249	109896	2725832	320313

The table shows the main deficits are in Beaufort, East Siberian seas and CAA.  Offsetting surpluses are in Laptev, Greenland and Central Arctic seas. The total deficit on this day is 72k km2 or 1.6%.  Note that 2007 did not add more ice as September ended.

Illustration by Eleanor Lutz shows Earth’s seasonal climate changes. If played in full screen, the four corners present views from top, bottom and sides. It is a visual representation of scientific datasets measuring Arctic ice extents and snow cover.