Arctic Sea Ice

Update: Strange Sea Ice Data July End 2025

Posted on by Ron Clutz

Update August 2, 2025

NSDIC acknowledged my query regarding the SII (Sea Ice Index) dataset, which is described below.  While awaiting an explanation I have investigated further.  My last download of the SII Daily Arctic Ice Extents was on July 30, meaning that the most recent data in that file was day 210, July 29.  The header on that file was Sea_Ice_Index_Daily_Extent_G02135_v3.  Then on August 1, the downloaded file had the heading Sea_Ice_Index_Daily_Extent_G02135_v4.  So it appears that these are now the values from a new version of SII.  As I wrote in my query, since March 14 all of the values for Arctic Ice Extents are lower in this new record.  The graph below shows the implications for July as an example.

You can see how v.4 in red is lower than v.3 in orange throughout the month.  It may be that v.3 values will no longer be reported in the future, though that has not been confirmed to me.  It should also be noted that v.3 values for 2024 and prior years have also been altered in v.4 and I intend to look into that impact.

Note:  After comparisons of monthly averages, results from the two versions appear comparable for previous years. The change started in January 2025 and will be the basis for future reporting.  The logic for this is presented in this document: Sea Ice Index Version 4 Analysis

In June 2025, NSIDC was informed that access to data from the Special Sensor Microwave
Imager/Sounder (SSMIS) onboard the Defense Meteorological Satellite Program (DMSP)
satellites would end on July 31 (NSIDC, 2025). To prepare for this, we rapidly developed version
4 of the Sea Ice Index. This new version transitions from using sea ice concentration fields
derived from SSMIS data as input to using fields derived from the Advanced Microwave
Scanning Radiometer 2 (AMSR2) sensor onboard the Global Change Observation Mission – W1
(GCOM-W1) satellite.
On 29 July 2025, we learned that the Defense Department decision to terminate access to
DMSP data had been reversed and that data will continue to be available until September 2026.
We are publishing Version 4, however, for these reasons:

• The SSMIS instruments are well past their designed lifespan and a transition to
AMSR2 is inevitable. Unless the sensors fail earlier, the DoD will formally end the
program in September 2026.
• Although access of SSMIS will continue through September 2026, the Fleet
Numerical Meteorology and Oceanography Center (FNMOC), where SSMIS data
from the DMSP satellite are downloaded, made an announcement that “Support
will be on a best effort basis and should be considered data of opportunity.” This
means that SSMIS data will likely contain data gaps.
• We have developer time to make this transition now and may not in the future.
• We are confident that Version 4 data are commensurate in accuracy to those
provided by Version 3.

Overview

Before presenting the MASIE and SII results for July, a note about a strange thing in today’s Sea Ice Index report.  I have sent a note to them requesting an explanation for why the values have been altered from those in the dataset just two days ago.  When attempting to add into my spreadsheets the final two July days, I noticed that all the previous values were now different.  Exploring further, going back to beginning of 2024 all values had changed, some showing larger extents and many showing smaller ice extents than previous recorded.

For 2024 the new values added ice extents with the average day gaining slightly (47k km2).  But in 2025 so far, the average day lost (-57k km2) compared to the values two days ago.  Curiously, since March 14, 2025 all days had lower values at a daily rate of -75k km2.  In sum, the altered values in 2025 removed ~11M km2 of ice extents so far, and 10M km2 of that since March 14.  In the report below, I excluded the altered SII values awaiting news from NSIDC.

After a sub-par March maximum, by end of May 2025 Arctic ice closed the gap with the 19-year average. Then in June the gap reopened and in July the melting pace matched the average, abeit four days in advance of average. The chart shows the July Arctic ice extents on average decline from 9.7M to 6.9M km2. MASIE started July ~5M km2 in deficit to average and ended the month ~4M km2 down, continuing to melt about four days in advance of the average decline. SII matched MASIE the first half of July, then tracked slightly lower the second half.

The regional distribution of ice extents is shown in the table below. (Bering and Okhotsk seas are excluded since both are now virtually open water.)

Region 2025212 Day 212 2025-Ave. 2020212 2025-2020
 (0) Northern_Hemisphere 6555733 6941055 -385322 5880746 674988
 (1) Beaufort_Sea 944231 793206 151025 875454 68777
 (2) Chukchi_Sea 621236 555019 66217 533748 87488
 (3) East_Siberian_Sea 683122 751512 -68390 329453 353669
 (4) Laptev_Sea 329581 370847 -41266 61979 267602
 (5) Kara_Sea 32436 166826 -134390 95539 -63103
 (6) Barents_Sea 1131 29555 -28424 23940 -22808
 (7) Greenland_Sea 228078 296681 -68603 282403 -54325
 (8) Baffin_Bay_Gulf_of_St._Lawrence 117170 150751 -33581 35368 81801
 (9) Canadian_Archipelago 460908 547942 -87034 515499 -54592
 (10) Hudson_Bay 73633 139798 -66165 92861 -19228
 (11) Central_Arctic 3062678 3137162 -74483 3033706.07 28972

The table shows  most regions in deficit with Kara the largest, and Canadian Archipelago and Central Arctic also sizable.  Hudson Bay and Greenland Sea will lose the rest of their ice in upcoming weeks. Surpluses in Beaufort and Chukchi offset about 220k km2 of losses elsewhere.

Why is this important?  All the claims of global climate emergency depend on dangerously higher  temperatures, lower sea ice, and rising sea levels.  The lack of additional warming prior to 2023 El Nino is documented in a post NH and Tropics Lead UAH Temps Lower May 2025.

The lack of acceleration in sea levels along coastlines has been discussed also.  See Observed vs. Imagined Sea Levels 2023 Update

Also, a longer term perspective is informative:

post-glacial_sea_level

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 NH snow cover.

Strange Sea Ice Data July End 2025

Posted on by Ron Clutz

Before presenting the MASIE and SII results for July, a note about a strange thing in today’s Sea Ice Index report.  I have sent a note to them requesting an explanation for why the values have been altered from those in the dataset just two days ago.  When attempting to add into my spreadsheets the final two July days, I noticed that all the previous values were now different.  Exploring further, going back to beginning of 2024 all values had changed, some showing larger extents and many showing smaller ice extents than previous recorded.

For 2024 the new values added ice extents with the average day gaining slightly (47k km2).  But in 2025 so far, the average day lost (-57k km2) compared to the values two days ago.  Curiously, since March 14, 2025 all days had lower values at a daily rate of -75k km2.  In sum, the altered values in 2025 removed ~11M km2 of ice extents so far, and 10M km2 of that since March 14.  In the report below, I excluded the altered SII values awaiting news from NSIDC.

After a sub-par March maximum, by end of May 2025 Arctic ice closed the gap with the 19-year average. Then in June the gap reopened and in July the melting pace matched the average, abeit four days in advance of average. The chart shows the July Arctic ice extents on average decline from 9.7M to 6.9M km2. MASIE started July ~5M km2 in deficit to average and ended the month ~4M km2 down, continuing to melt about four days in advance of the average decline. SII matched MASIE the first half of July, then tracked slightly lower the second half.

The regional distribution of ice extents is shown in the table below. (Bering and Okhotsk seas are excluded since both are now virtually open water.)

Region 2025212 Day 212 2025-Ave. 2020212 2025-2020
 (0) Northern_Hemisphere 6555733 6941055 -385322 5880746 674988
 (1) Beaufort_Sea 944231 793206 151025 875454 68777
 (2) Chukchi_Sea 621236 555019 66217 533748 87488
 (3) East_Siberian_Sea 683122 751512 -68390 329453 353669
 (4) Laptev_Sea 329581 370847 -41266 61979 267602
 (5) Kara_Sea 32436 166826 -134390 95539 -63103
 (6) Barents_Sea 1131 29555 -28424 23940 -22808
 (7) Greenland_Sea 228078 296681 -68603 282403 -54325
 (8) Baffin_Bay_Gulf_of_St._Lawrence 117170 150751 -33581 35368 81801
 (9) Canadian_Archipelago 460908 547942 -87034 515499 -54592
 (10) Hudson_Bay 73633 139798 -66165 92861 -19228
 (11) Central_Arctic 3062678 3137162 -74483 3033706.07 28972

The table shows  most regions in deficit with Kara the largest, and Canadian Archipelago and Central Arctic also sizable.  Hudson Bay and Greenland Sea will lose the rest of their ice in upcoming weeks. Surpluses in Beaufort and Chukchi offset about 220k km2 of losses elsewhere.

Why is this important?  All the claims of global climate emergency depend on dangerously higher  temperatures, lower sea ice, and rising sea levels.  The lack of additional warming prior to 2023 El Nino is documented in a post NH and Tropics Lead UAH Temps Lower May 2025.

The lack of acceleration in sea levels along coastlines has been discussed also.  See Observed vs. Imagined Sea Levels 2023 Update

Also, a longer term perspective is informative:

post-glacial_sea_level

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 NH snow cover.

Arctic Ice Melting 4 Days Faster Mid-July 2025

Posted on by Ron Clutz

After a sub-par March maximum, by end of May 2025 Arctic ice closed the gap with the 19-year average. Then in June the gap reopened and in July the melting pace matched the average, abeit four days in advance of average.

During this period the average year loses ~2.5M km2 of ice extent.   MASIE on day 166 was ~300k km2 down, and the gap increased to almost 550k km2 by June 30 (day 181). The deficit to average then reduced to ~350k km2, which persisted over the last 12 days

including yesterday, day 196. The graph shows MASIE 2025 matching the average on day 192, four days in advance.

The regional distribution of ice extents is shown in the table below. (Bering and Okhotsk seas are excluded since both are now virtually open water.)

Region 2025196 Day 196 2025-Ave. 2020196 2025-2020
 (0) Northern_Hemisphere 8007061 8358377 -351316 7556873 450188
 (1) Beaufort_Sea 1022304 866531 155773 931056 91248
 (2) Chukchi_Sea 718615 643869 74745 612932 105683
 (3) East_Siberian_Sea 976061 921340 54721 659117 316945
 (4) Laptev_Sea 645741 559270 86471 174286 471454
 (5) Kara_Sea 153545 360645 -207100 159679 -6134
 (6) Barents_Sea 14342 56080 -41738 39446 -25105
 (7) Greenland_Sea 387402 402761 -15359 400498 -13096
 (8) Baffin_Bay_Gulf_of_St._Lawrence 268783 311662 -42878 232167 36616
 (9) Canadian_Archipelago 630633 711293 -80660 733866 -103233
 (10) Hudson_Bay 155460 349275 -193815 520027 -364567
 (11) Central_Arctic 3032353 3171652 -139299 3093040.21 -60687

The table shows  the two largest deficits, the Atlantic Kara basin combined with Hudson Bay, exceed the total difference from average. In addition are lower ice extents in Central Arctic and Canadian Archipelago, offset by surpluses in Beaufort Sea and other Eurasian shelf basins.  Note that Hudson Bay with 350k km2 average ice extent yesterday will have less than 100k in three weeks.

Why is this important?  All the claims of global climate emergency depend on dangerously higher  temperatures, lower sea ice, and rising sea levels.  The lack of additional warming prior to 2023 El Nino is documented in a post NH and Tropics Lead UAH Temps Lower May 2025.

The lack of acceleration in sea levels along coastlines has been discussed also.  See Observed vs. Imagined Sea Levels 2023 Update

Also, a longer term perspective is informative:

post-glacial_sea_level

Climatists’ Childish Reading of Polar Ice

Posted on by Ron Clutz

Vijay Jayaraj  explains in his Cornwall Alliance article Climate-obsessives’ Infantile Reading of Polar Ice. Excerpts in italics with my bolds and added images.

Whenever “experts are shocked” they usually have marginalized or ignored altogether factors wrongly assumed to have no influence over their hypotheses, theories or beliefs.

Nowhere is this more evident than in climate science where changes in geophysical phenomenon continue to defy assumptions and forecasts presented by some of the most highly paid and influential scientists on the planet.

Among the most infamous examples is the failure of computer climate models to accurately predict real-world temperatures. This is predominantly due to the unscientific exaggeration of carbon dioxide’s (CO2’s) potency in warming the atmosphere.

Charts showing annual gains and losses of Surface Mass Balance (SMB) of Greenland Ice Sheet GIS. Note accumulations above the mean in these years. Note also that each year starts from zero, not showing additions from the previous year.

Now scientists have encountered more “shocks” as polar sea ice is refusing to behave as expected. Since September 1, 2024, an astonishing 579 billion tons of fresh snow and ice have blanketed the Greenland ice sheet, marking the most significant accumulation for that date in at least eight years—far surpassing the 1981-2010 average.

Meanwhile, both the North and South Poles are defying expectations, piling on more ice despite, as reported in hyperbolic headlines, “record-breaking” global heat. It’s a breathtaking, almost surreal twist in the story of our planet’s climate!

According to NASA, “Arctic sea ice reaches its minimum extent (the area in which satellite sensors show individual pixels to be at least 15% covered in ice) each September.”

In the post-2010 era, the September minimum extent of Arctic sea ice occurred in 2012, which was also the lowest since satellite measurements began in 1980. But ever since 2012, ice has been increasing or oscillating well above that year’s mark.

Likewise, the volume of sea ice has not significantly dropped since 2012 and there has been a nominal increase in volume since a low point of 2020.

So, why is the minimum coverage of Arctic sea ice holding above the level of 2012?

One of the most obvious reasons could be that CO2 is not as powerful a temperature control knob as claimed, which is a possibility that many well-funded scientists refuse to even take into consideration.

Also, remember that we are in the Holocene epoch, a warm geological phase between two glacial advances – one that ended about 10,000 years ago and the next expected to occur some number of thousand years hence. An upward tick in Arctic temperatures shouldn’t surprise us regardless of whether we emit CO2 or not. In fact, Arctic ice levels witnessed in the 17th century during the Little Ice Age were among the highest since continental glaciers blanketed Canada and extended into the lower 48 states to create the Great Lakes.

At one point, news media were abuzz with the unexpected gain in Antarctica’s ice mass. Antarctica gained ice from 2021 to 2023, with studies showing nearly 108 gigatons per year added, mainly due to increased snowfall in East Antarctica.

Data from Vostok and Concordia stations in East Antarctica indicate extremely cold temperatures in early May, with minimums of minus 106.6 degrees Fahrenheit at Concordia on May 12. With winter just beginning, the temperatures are likely to dive further.

As recently as 2023, Concordia station recorded one of its lowest temperatures for the current decade, a brutal minus 117.76 degrees. Similarly, at Western Antarctica’s Byrd Station, a likely all-time low of almost minus 50 degrees was recorded as recently as 2023. These numbers may be surprising, but they are in tune with the unpredictability of climate – and of nature in general. Let’s just admit it. Things are not as “straightforward” as crisis-obsessed scientists are making them out to be. The climate system is complex, and the science is not settled. Our understanding of climatic dynamics is in its infancy. And to suggest that changes –whatever the direction – in polar ice presage a catastrophe is infantile.

 

Near Normal Arctic Ice End of May 2025

Posted on by Ron Clutz

After a sub-par March maximum, in April and now in May 2025, Arctic ice has closed the gap with the 19-year average.

During May the average year loses 1.71 M km2 of ice extent.   MASIE showed 2025 losing slightly more, 1.78 M km2, while SII showed close to average at month end.   Throughout May both MASIE and SII tracked close to the 19 year average with a dipping lower mid month.

The regional distribution of ice extents is shown in the table below.

Region 2025151 Day 151 2025-Ave. 2007151 2025-2007
 (0) Northern_Hemisphere 11641897 11739951 -98055 11846659 -204762
 (1) Beaufort_Sea 1066232 1010120 56112 1059461 6771
 (2) Chukchi_Sea 941331 872869 68462 894617 46714
 (3) East_Siberian_Sea 1074738 1065906 8832 1069198 5540
 (4) Laptev_Sea 779394 828746 -49352 754651 24744
 (5) Kara_Sea 736946 831977 -95031 895678 -158732
 (6) Barents_Sea 291895 315440 -23544 323801 -31906
 (7) Greenland_Sea 670528 584085 86443 591919 78609
 (8) Baffin_Bay_Gulf_of_St._Lawrence 853619 904731 -51112 934257 -80637
 (9) Canadian_Archipelago 843914 812776 31138 818055 25859
 (10) Hudson_Bay 1046462 1081957 -35494 1077744 -31282
 (11) Central_Arctic 3216938 3220915 -3977 3230109.43 -13171
 (12) Bering_Sea 73534 115851 -42316 112352.8 -38819
 (13) Baltic_Sea 0 6015 -6015 0 0
 (14) Sea_of_Okhotsk 44702 175668 -130966 83076 -38375

The table shows  major deficits in the Pacific basins of Okhotsk and Bering combined are 173k km2. On the Atlantic side, Kara and Laptev combined to lose 144k km2.  The other regions are a mix of surpluses and deficits giving an overall result about 100k km2 below average or 0.8%.

Why is this important?  All the claims of global climate emergency depend on dangerously higher  temperatures, lower sea ice, and rising sea levels.  The lack of additional warming prior to 2023 El Nino is documented in a post April 2025 UAH Temps Little Changed For Now.

The lack of acceleration in sea levels along coastlines has been discussed also.  See Observed vs. Imagined Sea Levels 2023 Update

Also, a longer term perspective is informative:

post-glacial_sea_level

Arctic Ice: All’s Well Ending April 2025

Posted on by Ron Clutz

NOAA refers to the Month end Arctic ice extent by averaging the last five days extents.  Thus monthly gains and losses of ice can be obtained by subtracting the previous month end ice amount.  The chart above shows the April month end Arctic ice extents since 2007, comparing the two relevant datasets: Sea Ice Index (SII, based on satellite microwave sensors) and Multisensor Analyzed Sea Ice Extent (MASIE, based on multiple sources including several satellite sensors and visual analysis).

A sine wave pattern is evident starting after the low 2007 extent, rising to a peak in 2012, declining to 2019, before returning to the mean the last four years.

After a sub-par March maximum, now in April, 2025, Arctic ice has closed the gap with the 19-year average.

During April the average year loses 1.1M km2 of ice extent.  Meanwhile 2025 lost only 0.538 M km2, about half as much.  The end result is MASIE showing a slight deficit and SII a small surplus at end of April.

The regional distribution of ice extents is particularly revealing, as shown in the table below.

Region 2025120 Day 120 Ave. 2025-Ave. 2007120 2025-2007
 (0) Northern_Hemisphere 13428208 13510326 -82118 13108068 320140
 (1) Beaufort_Sea 1071001 1068240 2761 1059189 11811
 (2) Chukchi_Sea 963094 957153 5942 949246 13848
 (3) East_Siberian_Sea 1087137 1085746 1391 1080176 6961
 (4) Laptev_Sea 893105 891206 1899 875661 17444
 (5) Kara_Sea 927530 915007 12523 864664 62866
 (6) Barents_Sea 563013 552738 10275 396544 166470
 (7) Greenland_Sea 703059 661036 42023 644438 58621
 (8) Baffin_Bay_Gulf_of_St._Lawrence 1129634 1194283 -64650 1147115 -17481
 (9) Canadian_Archipelago 854878 849548 5330 838032 16846
 (10) Hudson_Bay 1249532 1238910 10622 1222074 27458
 (11) Central_Arctic 3244486 3231137 13349 3241034.13 3452
 (12) Bering_Sea 441499 477412 -35913 475489 -33990
 (13) Baltic_Sea 11180 21561 -10382 14683.79 -3504
 (14) Sea_of_Okhotsk 287204 363423 -76219 295743 -8539

The table shows only three significant deficits to average; Okhotsk is -72k km2, and Bering adds -40k, together greater than the overall -82k km2, which is 0.6% below average.  The other deficit in Baffin Bay is  offset by surpluses in nearly every other Arctic basin with the exception of Baltic Sea. Clearly the core Arctic ocean is solidly frozen, with a few fringe seas going to open water slightly ahead of schedule.

Why is this important?  All the claims of global climate emergency depend on dangerously higher temperatures, lower sea ice, and rising sea levels.  The lack of additional warming prior to 2023 El Nino is documented in a post March 2025 UAH Yo-yo Temps.

The lack of acceleration in sea levels along coastlines has been discussed also.  See Observed vs. Imagined Sea Levels 2023 Update

Also, a longer term perspective is informative:

post-glacial_sea_level

Arctic Ice Normal Mid-April 2025

Posted on by Ron Clutz

The animation shows end of March Arctic ice extents on day 91 over the last 19 years (length of MASIE dataset). Of course central Arctic basins are frozen solid, and the fluctuations are visible on the marginal basins both the Atlantic side (right) and the Pacific (left). Note the higher extents in 2012, followed by lesser ice, then overcome by 2024.

After a sub-par March maximum, now in mid-April, 2025 Arctic ice has mostly closed the gap with the 19-year average.

Day 75 is mid-March, typically near the highest daily extents of the year.  At that time 2025 was ~500k km2 below average, or Half a Wadham in deficit. By end of March this year the gap below average reached 600k km2.  However, note that over these 30 days MASIE shows an average ice extent loss of 781k km2, while 2025 lost almost no ice in April, hanging around the 14M km2 mark.  Both MASIE and SII showed the same resilience pattern in April 2025, well above 2021 and especially 2007.  The regional distribution of ice extents is particularly revealing.

Region 2025105 Day 105 Ave. 2025-Ave. 2007105 2025-2007
 (0) Northern_Hemisphere 13927695 14126275 -198580 13588722 338973
 (1) Beaufort_Sea 1071001 1069881 1119 1068692 2309
 (2) Chukchi_Sea 965989 964751 1238 961638 4352
 (3) East_Siberian_Sea 1087137 1085653 1484 1078666 8471
 (4) Laptev_Sea 897845 893756 4089 843501 54344
 (5) Kara_Sea 921800 923592 -1792 890594 31206
 (6) Barents_Sea 517245 621900 -104655 439904 77341
 (7) Greenland_Sea 710333 661040 49293 673585 36749
 (8) Baffin_Bay_Gulf_of_St._Lawrence 1306106 1274576 31530 1215526 90580
 (9) Canadian_Archipelago 854878 853052 1826 848812 6066
 (10) Hudson_Bay 1248738 1246317 2422 1208588 40150
 (11) Central_Arctic 3246240 3234033 12206 3235648.34 10591
 (12) Bering_Sea 657229 646796 10433 600281.22 56948
 (13) Baltic_Sea 13278 43789 -30511 23534.37 -10256
 (14) Sea_of_Okhotsk 427895 601889 -173994 491121 -63226

The table shows only two significant deficits to average; Okhotsk alone is -174k km2, nearly matching the overall total of -199k km2, which is 1.4% below average.  The other deficit in Barents is mostly offset by surpluses in nearly every other Arctic basin with the exception of Baltic Sea. Clearly the core Arctic ocean is solidly frozen, with a few fringe seas going to open water slightly ahead of schedule.

Why is this important?  All the claims of global climate emergency depend on dangerously higher temperatures, lower sea ice, and rising sea levels.  The lack of additional warming prior to 2023 El Nino is documented in a post Ocean Warms, Land Cools UAH February 2025.

The lack of acceleration in sea levels along coastlines has been discussed also.  See Observed vs. Imagined Sea Levels 2023 Update

Also, a longer term perspective is informative:

post-glacial_sea_level

Arctic Ice March Maximum 2025 in Perspective

Posted on by Ron Clutz

The animation shows end of March Arctic ice extents on day 91 over the last 19 years (length of MASIE dataset). Of course central Arctic basins are frozen solid, and the fluctuations are visible on the marginal basins both the Atlantic side (right) and the Pacific (left). Note the higher extents in 2012, followed by lesser ice, then overcome by 2024.

Climatology takes the March monthly average to indicate the annual maximum and September average as the minimum.  Dynamically, the Arctic gains and loses ice extents in this pattern:

The values in the chart are the month ending ice extents (last five days average) minus the ice extents at end of the previous month.  Thus positive numbers show ice gained each month, negative numbers ice lost in a given month.  SII (Sea Ice Index) provides a data file calculating and updating these results since 1980. Note that the peak month of March on average declines very slightly, while the minimum month of September on average gains a little ice extent.  Also the greatest average gain of ice is in October and the greatest loss of extent is in July.

Above is a chart of March Monthly averages since 2007. The variability shows, including 2024 well above the 19-year average and 2025 well below.

This graph shows variations of ice extents during March, on average and for some recent years along with 2007.  The exceptional extents in 2024 stand out, along with the more typical 2021 and 2007.  On average during March the Arctic loses about 400k km2 of ice.  2025 started March at 14M km2, about 900k km2 in deficit, and ended virtually the same 14M, 600k km2 below average on day 90. SII was slightly lower than MASIE for three weeks, then ended about the same.

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

Region 2025090 Ave Day 090 2025-Ave. 2007090 2025-2007
 (0) Northern_Hemisphere 14011379 14617665 -606287 14222916 -211537
 (1) Beaufort_Sea 1071001 1070241 760 1069711 1290
 (2) Chukchi_Sea 965989 964237 1752 966006 -17
 (3) East_Siberian_Sea 1087137 1086266 871 1074908 12229
 (4) Laptev_Sea 897845 897098 747 884340 13505
 (5) Kara_Sea 885597 920703 -35106 892157 -6560
 (6) Barents_Sea 450824 664324 -213500 441970 8854
 (7) Greenland_Sea 703578 665146 38433 686312 17266
 (8) Baffin_Bay_Gulf_of_St._Lawrence 1350818 1386137 -35320 1217467 133351
 (9) Canadian_Archipelago 854878 853269 1609 850127 4751
 (10) Hudson_Bay 1260903 1255273 5631 1229995 30908
 (11) Central_Arctic 3237488 3234612 2876 3242236.7 -4749
 (12) Bering_Sea 593465 711340 -117875 814787.71 -221323
 (13) Baltic_Sea 20341 62183 -41842 45896.93 -25556
 (14) Sea_of_Okhotsk 628758 836750 -207992 794657 -165899

Overall 2025 Arctic ice is 4% below the 19 year average and 1% below 2007.  About half of the 606k km2 deficit is in the Pacific basins of Bering and Okhotsk, typically the first to go to open water. The other major case of early melting is in the Atlantic Barents Sea.

Why is this important?  All the claims of global climate emergency depend on dangerously higher temperatures, lower sea ice, and rising sea levels.  The lack of additional warming prior to 2023 El Nino is documented in a post Ocean Warms, Land Cools UAH February 2025.

 

The lack of acceleration in sea levels along coastlines has been discussed also.  See Observed vs. Imagined Sea Levels 2023 Update

Also, a longer term perspective is informative:

post-glacial_sea_level

Arctic Ice Recovery Stalls January 2025

Posted on by Ron Clutz

Arctic ice recovered more slowly than usual in December and January, likely due to polar vortex pulling freezing air from the Arctic down into lower latitudes, replaced by warmer southern air.  A post at Severe Weather Europe is February 2025 Forecast, describing the dynamics this winter.  

After a mild start, a new Polar Express is looming
for the United States and Canada mid-month.

As January is slowly ending, we can look at preliminary surface temperature data for the month so far. Below is the CDAS analysis, and you can see that January was colder than normal across the entire United States, apart from California and parts of Nevada. But these anomalies do not show the full picture of just how cold some days in the month were, breaking records for several years and even decades in the past.

On the other hand, we can see that Canada had warmer than normal temperatures. This is an expected pattern, as while the colder air was transported further south into the United States, it was replaced by high-pressure and a warmer-than-normal airmass.

The movement of the pressure systems drives these temperature patterns and weather changes. Pairs of pressure systems are also known as Rossby Waves. You can see an example of Rossby waves in the image below by NOAA and how they are all connected and function with the jet stream.

The purple line connecting these pressure systems is called the jet stream. This rapid stream of air is found around 9 to 14 kilometers (6 to 9 miles) above sea level.

In late January, the average temperatures in the northern United States and southern Canada are still around or below freezing, so even a strong positive anomaly does not actually mean warm temperatures in that region. But, it is interesting to see the rapid shift in temperature anomalies as the pressure systems reposition.

February 2025 is about to start, with the latest weather forecasts indicating a very dynamic month over the United States and Canada. After the power struggle between the cold and warmth at the start of the month, another Polar Vortex lobe looms for the United States around mid-month.

Below is the surface temperature anomaly, averaged for next week. You can see the large supply of colder air over the northern United States and western Canada. Another cooler area is forecast for eastern Canada and the northeastern United States.

But most of the central and southern half of the United States is forecast to have above-normal temperatures. We often see such a division in the weather patterns, where the colder and warmer air separate along the jet stream.

Going into the weather trend for the second half of February, we will use the extended-range ensemble forecasts. These forecasts serve as trends that show the prevailing idea of where the pressure systems are positioned and how the airmass is expected to move.

The continuous low-pressure systems over Canada helped to initiate large-scale cold air transport from the Arctic into the United States and Canada, also powered by the Polar Vortex in the stratosphere.

We continue to see the presence of the low-pressure area over Canada in the forecast for February. But the forecast now indicates an interesting core movement of the Polar Vortex in the stratosphere, likely to initiate another deep cold event around mid-month over the United States and Canada.

Impact on Arctic Ice Extents

The 19-year average for January shows Arctic ice extents started at 13.13M km2 and ended the month at 14.36M km2.  2024 started somewhat higher and matched average at the end.  Other recent years have been lower, and 2025 started 540k km2 in deficit and 818k km2 below average at month end. The gap had closed to 400k km2 before losing extents at the end.  SII and MASIE tracked closely this month.

The table below shows year-end ice extents in the various Arctic basins compared to the 19-year averages and some recent years.  2007 seven was close to the average, so 2018 is shown for comparison.

Region 2025031 Ave Day 031 2025-Ave. 2018031 2025-2018
 (0) Northern_Hemisphere 13543740 14362137 -818398 13792271 -248532
 (1) Beaufort_Sea 1071001 1070386 614 1070445 556
 (2) Chukchi_Sea 965989 965974 15 965971 18
 (3) East_Siberian_Sea 1087137 1087063 74 1087120 18
 (4) Laptev_Sea 897845 897824 21 897845 0
 (5) Kara_Sea 921520 917381 4139 895363 26157
 (6) Barents_Sea 428814 563859 -135044 481947 -53133
 (7) Greenland_Sea 614789 613370 1418 501411 113378
 (8) Baffin_Bay_Gulf_of_St._Lawrence 1080930 1328380 -247450 1406903 -325972
 (9) Canadian_Archipelago 854878 853510 1368 853109 1769
 (10) Hudson_Bay 1260903 1260778 125 1260838 66
 (11) Central_Arctic 3211379 3210507 872 3184817 26562
 (12) Bering_Sea 534452 648807  -114354 382206 152245
 (13) Baltic_Sea 39334 62876  -23542 41713.99 -2380
 (14) Sea_of_Okhotsk 559692 823877  -264185 704398 -144707

This year’s ice extent is 818k km2 or 5.7% below average.  About half of the deficit comes from the Pacific basins of Bering and Okhotsk sea.  The other two major losses are in Barents Sea and Baffin Bay.  With the annual maximum typically occurring mid-March, it is likely the ice then will also be lower than usual.   

 

 

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 NH snow cover.

 

2024 Natural Climate Factors: Snow

Posted on by Ron Clutz

Previously I posted an explanation by Dr. Judah Cohen regarding a correlation between autumn Siberian snow cover and the following winter conditions, not only in the Arctic but extending across the Northern Hemisphere. More recently, in looking into Climate Model Upgraded: INMCM5, I noticed some of the scientists were also involved in confirming the importance of snow cover for climate forecasting. Since the poles function as the primary vents for global cooling, what happens in the Arctic in no way stays in the Arctic. This post explores data suggesting changes in snow cover drive some climate changes.

The Snow Cover Climate Factor

The diagram represents how Dr. Judah Cohen pictures the Northern Hemisphere wintertime climate system.  He leads research regarding Arctic and NH weather patterns for AER.

cohen-schematic2

Dr. Cohen explains the mechanism in this diagram.

Conceptual model for how fall snow cover modifies winter circulation in both the stratosphere and the troposphere–The case for low snow cover on left; the case for extensive snow cover on right.

1. Snow cover increases rapidly in the fall across Siberia, when snow cover is above normal diabatic cooling helps to;
2. Strengthen the Siberian high and leads to below normal temperatures.
3. Snow forced diabatic cooling in proximity to high topography of Asia increases upward flux of energy in the troposphere, which is absorbed in the stratosphere.
4. Strong convergence of WAF (Wave Activity Flux) indicates higher geopotential heights.
5. A weakened polar vortex and warmer down from the stratosphere into the troposphere all the way to the surface.
6. Dynamic pathway culminates with strong negative phase of the Arctic Oscillation at the surface.

From Eurasian Snow Cover Variability and Links with Stratosphere-Troposphere
Coupling and Their Potential Use in Seasonal to Decadal Climate Predictions by Judah Cohen.

Observations of the Snow Climate Factor

The animation at the top shows from remote sensing that Eurasian snow cover fluctuates significantly from year to year, taking the end of October as a key indicator.

For more than five decades the IMS snow cover images have been digitized to produce a numerical database for NH snow cover, including area extents for Eurasia. The NOAA climate data record of Northern Hemisphere snow cover extent, Version 1, is archived and distributed by NCDC’s satellite Climate Data Record Program. The CDR is forward processed operationally every month, along with figures and tables made available at Rutgers University Global Snow Lab.

This first graph shows the snow extents of interest in Dr. Cohen’s paradigm. The Autumn snow area in Siberia is represented by the annual Eurasian averages of the months of October and November (ON). The following NH Winter is shown as the average snow area for December, January and February (DJF). Thus the year designates the December of that year plus the first two months of the next year.

Notes: NH snow cover minimum was 1981, trending upward since.  Siberian autumn snow cover was lowest in 1989, increasing since then.  Autumn Eurasian snow cover is about 1/3 of Winter NH snow area. Note also that fluctuations are sizable and correlated.

The second graph presents annual anomalies for the two series, each calculated as the deviation from the mean of its entire time series. Strikingly, the Eurasian Autumn flux is on the same scale as total NH flux, and closely aligned. While NH snow cover declined a few years prior to 2016, Eurasian snow has trended upward afterward.  If Dr. Cohen is correct, NH snowfall will follow. The linear trend is slightly positive, suggesting that fears of children never seeing snowfall have been exaggerated. The Eurasian trend line (not shown) is almost the same.

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 ice and snow extents.