June 30 Arctic Ice Update

The image above, supported by the table later on shows that in June water has opened up as usual this time of year.  On the North American side, Bering and Okhotsk (bottom left) were already ice-free, so that Chukchi and Beaufort opened (bottom center).  Meanwhile, in Baffin Bay and Hudson Bay (bottom right) ice has retreated, and given the shallow depth of Hudson Bay it will go ice-free soon.

The picture is more mixed on the Euro-Russian side.  East Siberian (left) is nearly normal, with Laptev and Kara down (upper left) below the 12 year average.  Barents (upper center) has more ice than usual, and is still hanging onto Svalbard.

The graph below shows the surprising discrepancy between MASIE and SII  continued in June, but disappeared by month end.

Note that the  NH ice extent 12 year average declined from 11.8M km2 to 9.8M km2 during in the last 30 days.  MASIE 2019 shows a slower decline from 10.9M km2 to 9.3M km2.  Thus the current deficit to average has reduced during June from 778k km2 to 506k km2, or 5.2% of average. That track is close to 2010 and below other years. 

Region 2019181 Day 181 Average 2019-Ave. 2010181 2019-2010
 (0) Northern_Hemisphere 9318729 9824939  -506210  9245692 73037 
 (1) Beaufort_Sea 766793 910839  -144047  861079 -94286 
 (2) Chukchi_Sea 614737 721838  -107101  705357 -90619 
 (3) East_Siberian_Sea 1000185 1022188  -22003  1040103 -39918 
 (4) Laptev_Sea 600733 726543  -125810  693533 -92800 
 (5) Kara_Sea 494380 571373  -76993  623806 -129427 
 (6) Barents_Sea 188963 116290  72674  82722 106242 
 (7) Greenland_Sea 487331 509216  -21885  464399 22932 
 (8) Baffin_Bay_Gulf_of_St._Lawrence 431660 512914  -81254  416820 14840 
 (9) Canadian_Archipelago 777670 778719  -1049  735649 42020 
 (10) Hudson_Bay 754193 729807  24386  401862 352331 
 (11) Central_Arctic 3196694 3203485  -6791  3191924 4770 
 (12) Bering_Sea 1129 5122  -3994  594 535 
 (13) Baltic_Sea 0 -4  0
 (14) Sea_of_Okhotsk 3248 17144  -13897  26683 -23435 

The table shows where the ice is distributed to make the 5.2% defict to average.  Beaufort Chukchi and Laptev Seas make up most of the NH deficit to average, while Kara and Baffin contribute the rest.

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.

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Arctic Ice In Perspective

With Arctic ice melting season underway, warmists are again stoking fears about ice disappearing in the North.  In fact, the pattern of Arctic ice seen in historical perspective is not alarming. People are over-thinking and over-analyzing Arctic Ice extents, and getting wrapped around the axle (or should I say axis).  So let’s keep it simple and we can all readily understand what is happening up North.

I will use the ever popular NOAA dataset derived from satellite passive microwave sensors.  It sometimes understates the ice extents, but everyone refers to it and it is complete from 1979 to 2018.  Here’s what NOAA reports (in M km2):

We are frequently told that only the March maximums and the September minimums matter, since the other months are only transitional between the two.  So the graph above shows the mean ice extent, averaging the two months March and September.

If I were adding this to the Ice House of Mirrors, the name would be The X-Ray Ice Mirror, because it looks into the structure of the time series.   For even more clarity and simplicity, here is the table:

NOAA NH Annual Average Ice Extents (in M km2).  Sea Ice Index v3.0 (here)

Year Average Change Rate of Change
1979 11.697
1996 11.353 -0.344 -0.020 per year
2007 9.405 -1.949 -0.177 per year
2018 9.506  +0.102 +0.009 per year

The satellites involve rocket science, but this does not.  There was a small loss of ice extent over the first 17 years, then a dramatic downturn for 11 years, 9 times the rate as before. That was followed by the current plateau with no further loss of ice extent.  All the fuss is over that middle period, and we know what caused it.  A lot of multi-year ice was flushed out through the Fram Strait, leaving behind more easily melted younger ice. The effects from that natural occurrence bottomed out in 2007.

Kwok et al say this about the Variability of Fram Strait ice flux:

The average winter area flux over the 18-year record (1978–1996) is 670,000 km2, ;7% of the area of the Arctic Ocean. The winter area flux ranges from a minimum of 450,000 km2 in 1984 to a maximum of 906,000 km2 in 1995. . .The average winter volume flux over the winters of October 1990 through May 1995 is 1745 km3 ranging from a low of 1375 km3 in the 1990 flux to a high of 2791 km3 in 1994.

https://www.researchgate.net/publication/261010602/download

Conclusion:

Some complain it is too soon to say Arctic Ice is recovering, or that 2007 is a true change point.  The same people were quick to jump on a declining period after 1996 as evidence of a “Death Spiral.”

Footnote:

No one knows what will happen to Arctic ice.

Except maybe the polar bears.

And they are not talking.

Except, of course, to the admen from Coca-Cola

Mid June Arctic Ice Lopsided

In the first half of June 2019, the shift from ice to water is unusually lop-sided in two respects. The image above, supported by the table later on shows that in the last two weeks water has opened up faster on the Pacific side, and much slower on the Atlantic side, with the exception of Baffin Bay.  The other surprise is that MASIE shows much less ice than does SII, a reversal of the typical situation.

The graph below shows the surprising discrepancy between MASIE and SII appearing in May and continuing in June.

Note that the  NH ice extent 12 year average declined from 12.7M km2 to 10.9M km2 during in the last 30 days.  MASIE 2019 shows about the same decline from 11.9M km2 to 10.3M km2.  That track matched 2016 in May, but is now closest to 2010 and below other years.  Interestingly SII showed a much slower rate of ice extent loss, starting nearly the same as MASIE, but ended this period 400k km2 higher. and close to average and 2018.

I have no explanation for the differential between MASIE and SII.  Note that ice extents in both datasets are levelling off mid-June.

Region 2019166 Day 166 Average 2019-Ave. 2010166 2019-2010
 (0) Northern_Hemisphere 10340833 10933549 -592716 10534077 -193244
 (1) Beaufort_Sea 761369 968193 -206823 933194 -171824
 (2) Chukchi_Sea 680432 799211 -118778 839873 -159441
 (3) East_Siberian_Sea 1049046 1054090 -5045 1068901 -19856
 (4) Laptev_Sea 750164 778536 -28372 772185 -22021
 (5) Kara_Sea 671900 722641 -50741 717539 -45640
 (6) Barents_Sea 261587 215180 46408 138264 123324
 (7) Greenland_Sea 549038 568045 -19007 524612 24426
 (8) Baffin_Bay_
Gulf_of_St._Lawrence
558105 733399 -175294 667457 -109352
 (9) Canadian_Archipelago 787036 798742 -11706 766642 20394
 (10) Hudson_Bay 1014530 1004832 9698 826781 187749
 (11) Central_Arctic 3229461 3221030 8431 3206453 23008
 (12) Bering_Sea 17768 33002 -15234 21317 -3550
 (13) Baltic_Sea 0 7 -7 0 0
 (14) Sea_of_Okhotsk 9381 35292 -25911 83076 -73695

The table shows where the ice is distributed to make the 5.4% defict to average.  Beaufort and Chukchi Seas are more than half of the NH deficit to average, while Baffin has lost 175k km2 to average.

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.

May Arctic Ice Mixed Signals

The image above shows that ice began to disappear in earnest during May.  On day 120 (April 30), Bering and Okhotsk Seas (left bottom and far left) were already mostly water.  Elsewhere the first 10 days added some water, and then more rapidly in the last 20 days. The Central Arctic core is intact, including East Siberian and Laptev Sea on the Russian side (left) and Canadian Archipelago (center right) and Hudson Bay (far right).

Meanwhile Beaufort and Chukchi (bottom center) are opening up, along with Baffin (center below Greenland).

The graph below shows a surprising discrepancy between MASIE and SII appearing in May.

Note that the  NH ice extent 12 year average declined from 13.6M km2 to 11.8M km2 during May.  MASIE 2019 shows about the same decline from 12.7M km2 to 10.9M km2.  That track matches 2016, but well below other years.  Interestingly SII showed a much slower rate of ice extent loss, starting nearly the same as MASIE, but ended the month 600k km2 higher. and matching 2018. Some thoughts later on why the discrepancy and the below average extent this year.

Region 2019151 Day 151 
Average
2019-Ave. 2007151 2019-2007
 (0) Northern_Hemisphere 10939662 11844796 -905134 11846659 -906997
 (1) Beaufort_Sea 848114 1000716 -152602 1059461 -211347
 (2) Chukchi_Sea 738661 872393 -133732 894617 -155956
 (3) East_Siberian_Sea 1059805 1069104 -9299 1069198 -9393
 (4) Laptev_Sea 820403 831752 -11349 754651 65752
 (5) Kara_Sea 760439 849220 -88780 895678 -135239
 (6) Barents_Sea 268245 330718 -62473 323801 -55556
 (7) Greenland_Sea 500951 575983 -75031 591919 -90968
 (8) Baffin_Bay_Gulf_of_St._Lawrence 756455 931604 -175149 934257 -177802
 (9) Canadian_Archipelago 789111 748381 40730 818055 -28944
 (10) Hudson_Bay 1103650 1104185 -535 1077744 25906
 (11) Central_Arctic 3224969 3218320 6649 3230109 -5141
 (12) Bering_Sea 27192 135798 -108606 112353 -85161
 (13) Baltic_Sea 0 188 -188 0 0
 (14) Sea_of_Okhotsk 40429 105988 -65559 83076 -42647

The table shows where the ice is distributed to make the 7.6% defict to average.  The Pacific Basins of Bering and Okhotsk are ~170k km2 of the difference.  Baffin is 175k km2 below average. Chukchi and Beaufort are the other two large contributors to the 905k km2 deficit.

What’s Going on with Arctic Ice in May?

From Susan Crockford at Polar Bear Science

This is the time year when declining sea ice gets some people all worked up. However, declining ice is normal at this time of year and there is always variation in where the most open water appears first. At this time of year, there isn’t much ice ‘melt’ going on. Rather, what we are seeing is the opening up of shore leads and polynyas by winds.


A polynya (po·lyn·ya) is an area of year-round open water surrounded by heavier, thicker sea ice cover. Polynyas are marine oases in the Arctic, their nutrient-rich waters providing a place to feed, mate and overwinter for a wide range of species.

The North Water Polynya is fed by freshwater from melting ice caps in Greenland and Canada that mix with Pacific water columns snaking through underwater channels in the Northwest Passage and Lancaster Sound. These icy waters merge with a warmer Atlantic current and are carried up the west coast of Greenland.

Dr. Judah Cohen AER Arctic Oscillation and Polar Vortex Analysis and Forecasts
May 24, 2019 says:

Last year at this time, the Arctic was dominated by below normal geopotential height anomalies and this year the Arctic is dominated by above normal geopotential height anomalies. High heights/blocking in the Arctic favors troughing and cooler temperatures in the mid-latitudes and in that regard the high heights in the Arctic, especially on the North Atlantic side, favor troughing and relatively cool temperatures in Europe. If high heights/blocking in the Arctic especially near Greenland, can persist for much of the summer then parts of Europe could experience below normal temperatures this summer.

All forecasts predict a relatively warm summer for East Asia. Again, I think the trend is your friend in East Asia as well and the warm forecast is likely to verify. However as in Europe, persistent high heights/blocking to the north could flip the summer from hot to cool at least regionally.

Finally, if polar cap geopotential height anomalies remain on the warm/positive side for much of the summer, this could result in accelerated sea ice loss relative to recent summers.

Pacific, Not Arctic Ice Melting April 30

The image above shows the disappearing ice in the two Pacific basins over the last 16 days of April.  Okhotsk on the left melted steadily, losing 400k km2 of ice during this period, with only 260k km2 or 20% of its March maximum remaining. Bering Sea on the right actually gained 150k km2 ice extent up to 315k km2, before losing 215k km2 in the last four days, with only 100k km2 of ice left.

Meanwhile the Arctic core, Russian ice shelves and Canadian Archipelago remain frozen  The image above shows ice extent waxing and waning at the margins, especially in Bafffin Bay left of Greenland, and in Greenland Sea in the center.  Barents Sea on the right ended up about the same as it started this period.

The graph below shows how the April Arctic extents compared to the 12 year average and to some years of interest.
MASIE shows NH ice extents 800k km2 below the 12 year average at both the beginning and end of April.  SII ended the month slightly higher.  At this point 2019 is also tracking below 2018 and 2007.  The deficit is mostly due to open water in the Pacific basins.
The green line shows the average NH extents excluding Bering and Okhotsk ice,  The purple line shows the same for 2019, excluding B&O ice.  On day 90, the 12 year average included 1.7M km2 of B&O ice, which dropped to 0.9M by day 120.  In contrast 2019 started the month with 1.3M km2 of B&O ice, with only 0.3M left at month end.  As the table below will show, the over all deficit to average is 800k km2, and 550k km2 is due to Bering and Okhotsk melting.

Region 2019120 Day 120 
Average
2019-Ave. 2007120 2019-2007
 (0) Northern_Hemisphere 12845831 13636708 -790876 13108068 -262237
 (1) Beaufort_Sea 1070463 1068049 2414 1059189 11273
 (2) Chukchi_Sea 908742 957319 -48578 949246 -40504
 (3) East_Siberian_Sea 1082230 1085731 -3500 1080176 2054
 (4) Laptev_Sea 897845 891192 6653 875661 22184
 (5) Kara_Sea 921837 912762 9075 864664 57173
 (6) Barents_Sea 564996 551830 13166 396544 168452
 (7) Greenland_Sea 544988 647270 -102283 644438 -99450
 (8) Baffin_Bay_Gulf_of_St._Lawrence 1128210 1256132 -127923 1147115 -18905
 (9) Canadian_Archipelago 853337 847923 5414 838032 15305
 (10) Hudson_Bay 1255410 1243542 11868 1222074 33336
 (11) Central_Arctic 3245152 3237039 8114 3241034 4118
 (12) Bering_Sea 100108 515469 -415361 475489 -375381
 (13) Baltic_Sea 9715 22746 -13032 14684 -4969
 (14) Sea_of_Okhotsk 261111 396325 -135214 295743 -34632

Other than B&O losing ice, the other sizeable deficits to average are coming from Baffin Bay and Greenland Sea.  Of course, all of these basins will be ice-free as usual before September.

Drift ice in Okhotsk Sea at sunrise.

 

Bering Sea Ice Blues Mid April 2019

“Freedom’s Just Another Word for Nothing Left to Lose.” (Kris Kristofferson)

In April, Arctic ice extent is declining as usual with the notable exception of Bering Sea, along with ice retreating in nearby Okhotsk.  Bering still has some ice to lose, but at 178k km2 it is only 31% of the ice there January 27, the largest Bering extent this year.  It is unusual since the Bering ice is only 25% of the 12 year average for this date.  Nearby Chukchi Sea is hardly showing any open water, down only 10k km2 from its maximum.  Open water is also gaining in Okhotsk, the other Pacific basin, but ice extent there is still 6% above the 12-year average.

Elsewhere things are mostly typical with Russian and Canadian basins still frozen with high extents.  The other two places losing ice are Barents and Baffin Bay/Gulf of St. Lawrence shown below.
On the right side is Barents losing ice along the Russian coastline, while holding onto Svalbard.  On the left, water in Baffin Bay is pushing north along the western Greenland coast.  On the extreme left is open water taking over in Gulf of St. Lawrence

The graph below shows how the Arctic extent has faired since the March maximum compared to the 12 year average with and without the Pacific basins of Bering and Okhotsk.  The green line is the 12yr. average without B&O, while 2019 appears in purple when Bering and Okhotsk are excluded.
As of day 105, 2019 ice extent is 858k km2 below the 12yr. average, a gap of 6%.  529k km2 of that difference comes from the combined losses in Bering and Okhotsk.

The graph below shows March/April 2019 compared to average and some years of interest.

All years are tracking below the 12-year average.  2019 MASIE and SII are the same and well below 2018, largely due to Pacific ice losses. 2007 is only slightly higher than 2019 at this point.  The table below shows ice extents by regions comparing 2019 with 12-year average (2007 to 2018 inclusive) and 2007.

Region 2019105 Day 105 
Average
2019-Ave. 2007105 2019-2007
 (0) Northern_Hemisphere 13443363 14301788 -858425 13588722 -145359
 (1) Beaufort_Sea 1070498 1069781 717 1068692 1806
 (2) Chukchi_Sea 955995 965240 -9245 961638 -5643
 (3) East_Siberian_Sea 1087137 1086417 721 1078666 8471
 (4) Laptev_Sea 897845 893203 4642 843501 54344
 (5) Kara_Sea 932750 922684 10066 890594 42156
 (6) Barents_Sea 586518 611095 -24577 439904 146614
 (7) Greenland_Sea 601126 652308 -51182 673585 -72458
 (8) Baffin_Bay_Gulf_of_St._Lawrence 1133317 1349987 -216669 1215526 -82208
 (9) Canadian_Archipelago 853337 852527 810 848812 4526
 (10) Hudson_Bay 1238689 1252970 -14281 1208588 30101
 (11) Central_Arctic 3241460 3236044 5416 3235648 5811
 (12) Bering_Sea 177335 714883 -537548 600281 -422946
 (13) Baltic_Sea 16987 48771 -31784 23534 -6547
 (14) Sea_of_Okhotsk 648664 640205 8459 491121 157543

Of course both of these basins will melt out long before the September minimum, along with the Russian shelf seas.

As indicated earlier, Bering supplies almost 2/3 of the deficit to average, with Baffin Bay providing most of the other 1/3. Of course both of these basins will melt out long before the September minimum, along with the Russian shelf seas.

 

 

 

 

Arctic Ice Ides of March

The monthly average for March represents the annual maximum for Arctic ice extent.  The graph shows the 12-year March average in MASIE is 15M km2, with SII about 200k km2 less.  In this period six years were higher and seven lower, including a virtual tie between 2019, 2015 and 2007, slightly higher than 2017 and 2018.  In either MASIE or SII this March is ~330k km2 or 2% below the 12-year average.

As we will see, March 2019 ended with a flash melt that reduced extents dramatically in the final week or so.  First the graph of March comparing the daily extents.

Note that 2019 was close to average as recently as day 79 before dropping well below average and recent years.  As reported previously, most of the decline was due to early melting in Bering Sea, which loses its ice every Spring anyway. Below compares NH ice extents with and without Bering ice.

The gap between the black and green lines shows Bering contributed on average ~600k km2 to overall NH ice extents at the beginning of February, increasing to 800k km2 by end of March.  In 2019, the gap between the cyan and purple lines shows ~500k km2 of Bering Ice starting in February, decreasing to 140k km2 by March, then increasing up to 450k km2, and now back down to 180k km2. When the Bering volatility is set aside, the purple and green lines show Arctic ice excluding Bering was above average most of the month, and only slightly lower at the end.

So what has been happening?  In two words: Polar Vortex.  When cold Arctic air descends into parts of North America and Euarasia, warm moist air intrudes into the Arctic to replace it, and ice extents are reduced. For example, see the recently reported balmy weather in UK, and soon to be switched to bitter cold weather. From the Express  UK weather forecast: SHOCK Map shows Britain ENGULFED by freezing Arctic weather front

The cold front is shown in the image, The link underneath goes to the video.

//players.brightcove.net/2540076170001/B1Hli6KCG_default/index.html?videoId=6020946025001#t=12s

The table below shows extents for day 90 comparing 2019 to the 12 year average, and also showing the 600k km2 loss of ice in just 8 days at month end.

Region 2019090 Day 090 
Average
2019-Ave. 2019082 2019090-2019082
 (0) Northern_Hemisphere 13983435 14786570 -803135 14600645 -617210
 (1) Beaufort_Sea 1070498 1070149 348 1070291 207
 (2) Chukchi_Sea 945075 965775 -20700 966006 -20931
 (3) East_Siberian_Sea 1087137 1086034 1103 1087137 0
 (4) Laptev_Sea 897845 896685 1160 897845 0
 (5) Kara_Sea 892123 917893 -25770 926462 -34340
 (6) Barents_Sea 515799 658886 -143086 681050 -165251
 (7) Greenland_Sea 585051 659518 -74467 552178 32873
 (8) Baffin_Bay_Gulf_of_St._Lawrence 1343734 1456673 -112939 1431122 -87388
 (9) Canadian_Archipelago 853337 852817 520 853337 0
 (10) Hudson_Bay 1260903 1253798 7105 1260903 0
 (11) Central_Arctic 3238381 3233007 5374 3227734 10647
 (12) Bering_Sea 178917 803209 -624292 446151 -267235
 (13) Baltic_Sea 25134 68136 -43002 41886 -16752
 (14) Sea_of_Okhotsk 1086939 851929 235010 1150521 -63582

Note that BCE (Beaufort, Chukchi and East Siberian) is rock solid, along with Laptev.  Atlantic melting has begun, with the largest losses in Barents and Baffin Bay.  The major deficit in Bering is there, And while Okhotsk has started melting, it remains 235k km2 above average at this time.

Bering Ice March Madness

In February the media breathlessly told us that Bering Sea ice has melted away, and thus Arctic ice is doomed.  Now we see that reports of the demise were premature.  More surprising than the early retreat, Bering ice roared back in the last two weeks, and continues to grow even after the overall NH ice extent peaked

Two Weeks of Growing Bering Ice: The above image shows the last two weeks of dramatic ice growth in Bering with only minor melting in Okhotsk. Bering Sea on the right more than doubled, adding 250k km2 and effectively sealing off Chukchi inside the Arctic.  Meanwhile on the left Okhotsk ice seesawed, ending up 150k km2 lower, but still at 88% of 2019 maximum.
The graph below shows March progress in ice extent peaking and beginning the melt season. As noted before, the month started with a sharp increase nearly reaching average and 15M km2. After March 12, ice declined steadily as is normal after mid-March.  2019 extent is running lower than the 12 year average, but slightly higher than other recent years.  SII is showing about 100k km2 less ice than MASIE.

The table below shows the distribution of ice in the various Arctic basins.

Region 2019082 Day 082 
Average
2019-Ave. 2018082 2019-2018
 (0) Northern_Hemisphere 14600645 14891081 -290436 14511954 88692
 (1) Beaufort_Sea 1070291 1070115 176 1070445 -154
 (2) Chukchi_Sea 966006 965595 411 966006 0
 (3) East_Siberian_Sea 1087137 1086844 293 1087137 0
 (4) Laptev_Sea 897845 897552 293 897845 0
 (5) Kara_Sea 926462 917591 8871 934807 -8344
 (6) Barents_Sea 681050 653698 27352 720725 -39675
 (7) Greenland_Sea 552178 642867 -90689 539109 13069
 (8) Baffin_Bay_Gulf_of_St._Lawrence 1431122 1509559 -78437 1346761 84361
 (9) Canadian_Archipelago 853337 852881 456 853109 229
 (10) Hudson_Bay 1260903 1255967 4937 1260838 66
 (11) Central_Arctic 3227734 3227309 426 3158495 69240
 (12) Bering_Sea 446151 773234 -327083 345861 100291
 (13) Baltic_Sea 41886 87497 -45611 135848 -93962
 (14) Sea_of_Okhotsk 1150521 933366 217155 1183119 -32598

The table shows how 2019 is 290k km2 or 2% below the 12-year average.  Most basins are matching average extent, including Barents Sea edging slightly ahead of average.  Greenland Sea and Baffin Bay are below average. Despite recent gains, Bering ice is 327k km2 in deficit to average, nearly the difference in overall NH extent.  Meanwhile Okhotsk is 217k km2 surplus to average, partially offsetting Bering.

 

 

 

 

Arctic March Heart Beat

Above are ice charts from AARI, St. Petersburg for the annual maximum weeks in Mid-March, 2008 to 2019 inclusive. The brown color signifies Old Ice that survived at least one summer’s melt season.  The Arctic heart is beating clear and strong. Note differences between diminished years like 2012 and 2013 compared to more robust recent years.

For context, note that the average daily maximum has been ~15M, so on average the extent shrinks to 30% of the March daily high before growing back the following winter.

 

Arctic Ice Marching 2019

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.