Eleven Days in Pacific Arctic are shown in the above animation.  In the upper center, Chukchi finally froze completely, adding 260k km2 of ice to reach 99.8% of maximum.  (Disregard the blue jagged arc as a sensor artifact.)  Meanwhile, serious freezing began in the two Pacific basins.  Bering to the south of Chukchi went from 57k km2 to 195k, now 43% of maximum.  Okhotsk to the left went from 58k km2 to 223k, now 19% of maximum.

The graph below shows December progress in ice extent recovery.

From days 335 to 339, 2018 extents were flat and went below average.  Now freezing has resumed as shown in the animation above and tracking close to average again in the graph.  At day 349 (Dec. 15) MASIE shows 2018 1 day behind average (100k km2),  200k km2 greater than SII 2018,  140k km2 greater than 2007 and 358k km2 more than 2016.

 

The central Arctic and Eurasian shelf seas are completely frozen, typical for this time of year.  The Pacific was a little slower than usual to start, but is now coming on strong.  The Canadian side froze early and is of course locked in for the winter.  The only remaining deficit of note is Barents Sea which hasn’t added ice in the last two weeks.

Seventeen Days in Hudson Bay are shown in the above animation.  In the lower center, Hudson Bay pushed its ice extent up to 1.24M km2, 98% of maximum.  Just to the northeast, Hudson Strait and Ungava Bay are completely frozen over, with Baffin Bay reaching down.  At the top left you can see Chukchi Sea growing ice toward Bering Strait.

The graph below shows recent progress in ice extent recovery.

From days 330 to 339, 2018 extents were flat and went below average.  Now freezing has resumed as shown in the animation above and nearing average again in the graph.  At day 342 (Dec. 8) 2018 is 540k km2 greater than 2007 and 400k km2 more than 2016.

 

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

Region	2018342	Day 342  Average	2018-Ave.	2007342	2018-2007
(0) Northern_Hemisphere	11502523	11629820	-127297	10963264	539259
(1) Beaufort_Sea	1070498	1069593	905	1062538	7960
(2) Chukchi_Sea	790911	866476	-75565	649261	141650
(3) East_Siberian_Sea	1087137	1082340	4798	1043563	43574
(4) Laptev_Sea	897845	897834	11	897845	0
(5) Kara_Sea	783104	815899	-32796	809723	-26620
(6) Barents_Sea	109526	309994	-200468	215095	-105568
(7) Greenland_Sea	499296	567272	-67976	479113	20183
(8) Baffin_Bay_Gulf_of_St._Lawrence	868077	783249	84828	740590	127487
(9) Canadian_Archipelago	853337	853057	280	852556	781
(10) Hudson_Bay	1237622	844887	392735	948899	288723
(11) Central_Arctic	3126752	3204662	-77910	3174734	-47982
(12) Bering_Sea	82425	197632	-115207	39832	42593
(13) Baltic_Sea	2859	7895	-5037	2898	-39
(14) Sea_of_Okhotsk	90248	122364	-32116	45331	44917

 

The table shows how early is the freezing in Hudson Bay nearly offsetting slower ice buildup in Bering and Barents Seas.  It appears that the Pacific ice extents in Bering and Okhotsk Seas may again be slower than average this year.  The deficits there match the overall 2018 deficit to average.

Eighteen Days in Hudson Bay are shown in the above animation.  In the lower center, Hudson Bay more than doubled its ice extent up to 1.07M km2, 85% of maximum.  Just to the northeast, Hudson Strait and Ungava Bay are almost frozen over, with Baffin Bay reaching down.  At the top right you can see Greenland Sea ice reaching out toward Iceland.

The remarkable growth of Arctic ice extent in November 2018 overcame the October deficit,  went 400k km2 over the 11 year average and exceeded all but one year in the last decade. The graph below compares the last 12 November ice extents.

 

The monthly average of all November days shows 2018 matching the 11 year average, slightly higher than 2007, and 1M km2 greater than 2016.  The graph below shows the daily growth of ice extents throughout November, on average and for some important years.

2018 ice growth slowed so that it only slightly exceeded the 11 year average at month end.  At 11.15M km2, it was higher than other recent years, 1M km2 greater than 2016.

Dr. Judah Cohen at AER  posted on Dec. 3 explaining the November dynamics.  Excerpts in italics with my bolds.

In the month of November there were two distinct pulses of vertical energy transfer from the troposphere to the stratosphere that resulted in a perturbation of the stratospheric PV and a displacement of the PV towards Eurasia with an elongation towards eastern North America and a warming centered near Alaska and Northwestern Canada. However, those pulses were not simply absorbed by the polar stratosphere but in large part ricocheted or reflected off the stratospheric PV and back into the troposphere. So that in large part forced a similar pattern in the troposphere that it did in the stratosphere. The vertical energy transfer and the subsequent boomerang back down creating a similar pattern in both the stratosphere in troposphere happens very quickly over a matter of days. The tropospheric pattern of ridging near Alaska and western Canada with troughing in eastern North America and the northerly flow between the two atmospheric features delivered a relatively cold November to Eastern Canada and the Eastern US (see Figure i).

But now we have a new month and still more active vertical energy transfer as indicated by the red shading in Figure 11. For the first half of December there are predicted two or three distinct vertical energy pulses. But what is missing so far for the month of December is any blue shading, these waves are not being reflected or ricocheting off the stratospheric PV but are almost completely being absorbed in the stratosphere. This wave energy should therefore have a bigger and more lasting impact on the stratospheric PV. From Figure 10 we can already see hints of this. For the first time this fall and now winter 2018/2019 the polar cap heights are predicted to be above normal in the middle stratosphere. But my expectation is that this latest perturbation of the stratospheric PV will be evolving for weeks and not days and the peak will likely occur either in late December or early January. Also the eventual impact on the troposphere will be weeks and not days.

But because there is no reflecting or returning signal from the stratosphere what is dominating the troposphere is the thermal advection or the migration of air masses across the NH. As I discussed last week and again today this transport of heat is usually characterized by a cold East Asia and western North America and a mild eastern North America and if you look at Figures 3, 6 and 8 this is generally the temperature pattern that is being predicted over the next two weeks with the focus of the cold across Siberia, East Asia and Alaska. Eastern North America is predicted to turn much milder starting next week. I am not as sure what is the impact for Europe during active vertical energy transfer and I thought maybe mild but the forecast for Europe is vacillating between mild and cold but turning milder across Northern Europe.

Meanwhile, in Nunavut, it is a great time to be a polar bear, even more of them than people want.

 

 

The remarkable growth of Arctic ice extent continues with a new development yesterday, as shown by the graph below.

Note that as of day 330, Nov. 26, 2018, Arctic ice extent exceeds the 11 year average reached at month end.  At 11.08M km2, it is 400k km2 above the average for day 330.  It also matches 2013 (not shown) with only 2014 slightly higher in the last decade.

 

Dr. Judah Cohen at AER posted yesterday on the difficulties forecasting this winter’s coming months.  Excerpts in italics with my bolds.

In my opinion troposphere-stratosphere coupling is now in full gear and is having a significant impact on the large-scale circulation of the atmosphere. The relatively active vertical transfer of energy from the troposphere to the stratosphere is repeatedly perturbing the stratospheric PV though it is not of sufficient magnitude to force a significant PV disruption but only minor disruptions. Still the stratospheric PV is predicted to be continuously displaced from the North Pole towards northwest Eurasia. The displacement of the stratospheric PV south of its normal position is allowing the stratospheric PV to grab milder temperatures from more southern latitudes and sling shot it from across Asia towards Eastern Siberia and Alaska, where the warming temperatures are building ridging/positive geopotential height anomalies in the stratosphere centered near Alaska. This is resulting in northerly flow between the Alaskan ridge and stratospheric PV on the North Atlantic side of the Arctic from central Siberia to eastern North America. We have seen the same flow already mimicked or repeated in the troposphere during the month of November contributing to an overall cold month of November in the Eastern US.

As far as the winter as a whole, I believe that the behavior of the stratospheric PV is critical. The vertical atmospheric energy transfer looks active to me for the foreseeable future. This could lead to a significant or major stratospheric PV as early as the second half of December and extending into early January. If a large stratospheric PV disruption were to occur in the late December and early January timeframe this would be almost ideal in contributing to an overall cold winter for the usual favored regions across the NH mid-latitudes, but each event is unique. Any delay in a significant stratospheric PV disruption would lead to an extended period of volatile weather and increase the odds for an overall mild winter especially if the stratospheric PV strengthens and becomes circular in shape. There is the scenario where the vertical energy transfer remains active, the stratospheric PV is perturbed but no significant disruptions occur and the Eastern US still experiences a cold winter ala winter 2013/14 and is described in our new paper: Kretschmer et al. 2018, but more on the paper in a future blog.

 

Meanwhile, in Nunavut, it is a great time to be a polar bear, even more of them than people want.

 

The title of this post is over the top, but was provoked by the repeated claims last summer earth was going to hell right now.  For example,

The world’s summer of hell.  Hot, hot, hot: Summer of extremes setting heat records around the world, July 2018, CBC

Summer 2018: On the highway to hell? August 2018, Beyond Ratings

Earth at risk of becoming ‘hothouse’ if tipping point reached, if we can’t stop it we’re in a hell of a mess..August 2018, CNN

The Summer of Hell.  Climate change is here and we are living in its embers.  August 2018 The Week (US)

Meanwhile, back in reality, Arctic ice is spreading everywhere.  The image below shows the European side in the last two weeks:

Laptev and East Siberian in the middle are frozen solid. On the right Kara has added 400k km2 ice extent up to 700k km2, 75% of March maximum.  Below is the freezing proceeding on the Canadian side.

Baffin Bay in the center next to Greenland is extending south and added 300k km2.  Hudson Bay on the left added 400k km2, with the western coastline freezing all the way down into James Bay.  The graph below shows 2018 is matching the 11-year average after being down in October.

Both MASIE and SII have 9.9M km2 ice extents matching the average for day 320, Nov. 16.  2007, 2012 and 2017 all recovered from their September lows, while 2016 was much slower to refreeze.

Region	2018320	Day 320  Average	2018-Ave.	2007320	2018-2007
(0) Northern_Hemisphere	9937017	9942096	-5078	9824193	112824
(1) Beaufort_Sea	1069588	1064590	4999	1059182	10406
(2) Chukchi_Sea	615028	667249	-52222	519486	95541
(3) East_Siberian_Sea	1085198	1077597	7601	1055581	29617
(4) Laptev_Sea	897845	897648	197	897845	0
(5) Kara_Sea	701192	655668	45524	774297	-73105
(6) Barents_Sea	65798	167138	-101340	149482	-83684
(7) Greenland_Sea	378273	482289	-104016	533946	-155672
(8) Baffin_Bay_Gulf_of_St._Lawrence	711715	555346	156369	545899	165816
(9) Canadian_Archipelago	853337	851902	1435	852539	798
(10) Hudson_Bay	426092	261863	164228	244531	181560
(11) Central_Arctic	3107467	3186378	-78911	3163043	-55576

Deficits in Chukchi, Greenland and Barents Seas are offset by surpluses in Kara Sea, Baffin and Hudson Bays.

Meanwhile, in Nunavut, it is a great time to be a polar bear, even more of them than people want.

When Hell Freezes Over (Eagles Reunion Tour)

 

Russian Coastline Freezes in last Ten days

With the Canadian Arctic already frozen over, the action has moved to the Russian side.  The image above shows East Siberian and Laptev basins filling in completely.  Meanwhile on the right Kara Sea has gone from open water to nearly half of last March maximum.  Kara went from 114k km2 on day 298 to 435k km2 yesterday, 47% of March max.

The graph shows MASIE reporting ice extents totaling 9.0M km2 yesterday,  matching the 11 year average (2007 to 2017 inclusive).  Notice that 2018 lagged the average by 900k km2 on day 296 and overcame that gap in 13 days.  Presently, 2018 is tracking  300k km2 above 2007, 600k km2 more than 2012, and  1.3M km2 more than 2016. NOAA’s Sea Ice Index continutes to match MASIE through this period.

 

The current IMS Snow and Ice Chart shows how snow is covering Siberia completely, and has spread over northern and eastern canada.  Snow cover is an important indicator for the coming Arctic and NH winter, as explained by Dr. Judah Cohen in his latest AER arctic oscillation update (here).  Excerpts in italics with my bolds.

What unfolds next with the stratospheric PV (Polar Vortex) and troposphere-stratosphere coupling could be critical for determining the average temperature for the winter (December-January-February). Currently the GFS is predicting that the vertical transfer of energy from the troposphere to the stratosphere will become relatively quiet after this week. This will allow the stratospheric PV to recover and strengthen the second half of November. If the stratospheric PV becomes relatively strong and circular in shape in early December and couples to the mid and lower troposphere, this will likely result in a mild to extremely mild pattern across much of the NH including the Eastern US and northern Eurasia. At least for the Eastern US, it will be very difficult to recover from a mild start to winter and the winter temperatures would likely average mild regardless of what transpired the remainder of winter. Across northern Eurasia including Europe I think the outcome is a little more in doubt, as we saw last winter, Northern Eurasia and Europe can still average below normal for winter even with a mild start.

However an alternate path is that the energy pulse predicted for this week is not unique but is followed by subsequent pulses that further perturb the stratospheric PV. I see no evidence of this from the latest GFS forecasts, however in my opinion the NH tropospheric circulation remains favorable for subsequent PV disruptions. I think the place to watch is Siberia. As long as Siberia remains cold further energy pulses are likely with disruption to the stratospheric PV. However if Siberia turns mild for an extended period then we should expect a relatively strong PV for at least several weeks.

I would also like to note several trends. Snow cover extent remains above normal across North America. I do believe that snow cover can foreshadow the weather and the early season cold air outbreak across Eastern North America was at least preconditioned by the extensive snow cover for the entire fall this year. As long as the snow cover remains extensive and resilient, eastern North America remains at risk for subsequent cold air or Arctic outbreaks. However in the near term snow cover advance has been most impressive across Asia and with the more extensive snow cover, cold air is building across Siberia and is predicted to become more widespread. And just as I discussed above how long the snow and cold persist across Asia could be critical for the character of the winter not just locally but even remotely including the Eastern US.

 

 

 

 

Big Chill in last Two Weeks

The major growth in ice extent came in the Russian basins (right side).  The image above shows massive gains in ice extent in East Siberian and Laptev seas. East Siberian added 460k km2 for a total of 895, or 82% of last March maximum.  Laptev was mostly open water in September, but added 600k km2 in the last two weeks for a total of 700k km2 or 78% of last March maximum. With the Canadian Arctic on the left already frozen over, the gains were smaller, limited to northern Hudson Bay (top left) and Baffin Bay filling in from the north.

The graph shows MASIE reporting ice extents totaling 8.2M km2 yesterday,  400k km2 below the 11 year average (2007 to 2017 inclusive).  Note how 2018 started October on average, then went fairly flat the first week or so, falling 900k km2 below average.  Recent gains in ice extent exceed average gains, closing the gap.  Presently, 2018 is three days behind the average, matching 2007 and tracking above 2016 and 2012. NOAA’s Sea Ice Index matched MASIE throughout October.

The current IMS Snow and Ice Chart shows how snow is covering Siberia completely, and has spread over northern and eastern canada.

The table below shows the regional distribution of Arctic ice extents.

Region	2018304	Day 304  Average	2018-Ave.	2007304	2018-2007
(0) Northern_Hemisphere	8167466	8561136	-393671	8175072	-7606
(1) Beaufort_Sea	1069285	948751	120534	1038126	31159
(2) Chukchi_Sea	412073	468794	-56721	242685	169389
(3) East_Siberian_Sea	894863	954841	-59978	835071	59792
(4) Laptev_Sea	698238	896167	-197929	887789	-189551
(5) Kara_Sea	299264	462673	-163409	311960	-12695
(6) Barents_Sea	4058	81432	-77375	52823	-48765
(7) Greenland_Sea	341543	416633	-75090	443559	-102016
(8) Baffin_Bay_Gulf_of_St._Lawrence	427557	271561	155996	289374	138184
(9) Canadian_Archipelago	823551	789952	33599	817220	6331
(10) Hudson_Bay	131284	85823	45461	48845	82439
(11) Central_Arctic	3063891	3173126	-109235	3206345	-142454

The deficits are mainly on the Russian and European seas, only partly offset by surpluses in Beaufort, CAA, Baffin and Hudson Bays.

 

 

 

Siberian Big Chill in last Ten days

With the Canadian Arctic already frozen over, the action has moved to the Russian side.  The image above shows massive gains in ice extent in East Siberian and Laptev basins. East Siberian added 383k km2 for a total of 821, or 75% of last March maximum.  Laptev was mostly open water in September, but added 550k km2 in the last ten days for a total of 650k km2 or 72% of last March maximum.

The graph shows MASIE reporting ice extents totaling 7.8M km2 yesterday,  400k km2 below the 11 year average (2007 to 2017 inclusive).  Note how 2018 started on average, then went fairly flat the first week or so, falling 900k km2 below average.  Recent gains in ice extent exceed average gains, closing the gap.  Presently, 2018 is about four days behind the average, tracking above 2016, 2012 and 2007. NOAA’s Sea Ice Index is matching MASIE through most of October.

The current IMS Snow and Ice Chart shows how snow is covering Siberia completely, and has spread over northern and eastern canada.

 

 

 

October Days in Nunavut

Previous posts described how the Northwest Passage was treacherously laden with ice this year.  The image above shows how the freezing proceeded in this region over the last 16 days.  Oct. 1 the CAA ice extent (Canadian Arctic Archipelago) was 609k km2, then waffled back and forth until growing sharply the last four days to 786k km2.  On the right, Baffin Bay also doubled in that period up to 150k km2.  On the left and bottom, Beaufort Sea added 324k km2 up to 943k km2, nearly 90% of the maximum last March.

The graph shows MASIE reporting ice extents totaling 5.96M km2 yesterday,  700k km2 below the 11 year average (2007 to 2017 inclusive).  Note how 2018 started on average, then went fairly flat the first week or so, and lately is adding extent at the same rate as the average.  Presently, 2018 is about five days behind the average, tracking closely the 2016 ice growth.  NOAA’s Sea Ice Index is matching MASIE,  while 2007 and 2012 are not far behind.

The current IMS Snow and Ice Chart shows how snow cover is spreading rapidly across both Canada and Siberia.  Dr. Judah Cohen comments on this aspect at his AER blog Arctic Oscillation and Polar Vortex Analysis and Forecasts  Excerpts in italics with my bolds.

I present what is I believe is the latest European Centre for Medium Range Weather Forecasts (ECMWF) winter forecast in Figure i taken from climate.copernicus.eu. The ECMWF model is generally considered the best forecast model on the planet. The first thing that jumps out at me is the predicted classic or text book positive Pacific North American (PNA) pattern with a deep Aleutian Low, ridging or elevated heights across northwestern North America including Alaska and troughing or low heights in the Southeastern US. The ECMWF model is also predicting a quasi-negative NAO with the southern pole or center of action more classically represented than the northern pole. But in regards to the US winter this represents a suppressed storm track along the Eastern Seaboard. A positive PNA should yield an overall cold winter to the Eastern US. The ECMWF model is most confident in a relatively cold winter in the Southeastern US with greater uncertainty in the Northeastern US while the suppressed storm track will bring elevated risks of East Coast snowstorms. And El Niño does tend to focus the greatest snow threat, at least relative to normal, in the Mid-Atlantic. If you are a winter weather enthusiast especially a snow lover living in the Mid-Atlantic this ECMWF winter forecast should have you very excited.

The other feature that jumps out at me is high latitude blocking. I already mentioned the blocking near Alaska but there is a second center near Scandinavia that extends eastward into the Barents-Kara Seas. If the ECMWF was predicting a textbook negative NAO this block would be closer to Greenland. I believe that if the ECMWF forecast is correct and the block sets up near Scandinavia this is not as cold for Europe as the classic negative NAO but would instead focus the cold more in Asia. However I do think some of that cold would likely be drawn eastward underneath the blocking high and could result in a cold, possibly snowy winter for Central and/or Southeastern Europe. The other thing to watch is that a blocking high near Scandinavia and the Barents-Kara Seas coupled with a deep Aleutian Low is ideal for transferring energy from the troposphere into the stratosphere forcing a PV disruption. Now I don’t believe the ECMWF forecast is a consequence of a polar vortex disruption but is strongly suggestive of one. And if one does occur, then I would expect an increased probability of a more classic negative NAO to follow.

 

 

 

With ten years of hyped claims about Arctic sea ice declining, it takes effort to remember that ice in the Northern Hemisphere isn’t going away.  This year’s monthly average for September (the annual minimum) is slightly lower than 2017, but still well above 2007.  MASIE shows a surplus of 300k km2 and SII shows 450k km2.  As a result, both linear trends are slightly positive, though I would call it a “plateau, ” as opposed to a “death spiral.”

Twelve Days in Nunavut

Previous posts described how the Northwest Passage was treacherously laden with ice this year.  The image above shows the flash freezing in this region over the last twelve days.  Sept. 18 the CAA ice extent (Canadian Arctic Archipelago) was 321k km2, close to its annual minimum.  Yesterday MASIE showed 606k km2,  a increase of 90% in that region.

The graph shows MASIE reporting Arctic ice extents totalling 4.93M km2 yesterday,  35k km2 below the 11 year average (2007 to 2017 inclusive).  NOAA’s Sea Ice Index is the same as MASIE, 2007 was 845k km2 lower, and 2012 1.1M km2 less ice extent.  A dip on day 252 to  4.43M km2 was an early daily minimum for the year.  As shown in the first graph, the September monthly average exceeded 2007 by 300k in MASIE and  400k km2 in SII.

The table below shows ice extents in the regions comprising the Arctic in September.

Region	2018273	Day 273  Average	2018-Ave.	2007273	2018-2007
(0) Northern_Hemisphere	4931836	4966893	-35057	4086883	844953
(1) Beaufort_Sea	622520	527098	95422	498743	123777
(2) Chukchi_Sea	134120	210769	-76649	51	134069
(3) East_Siberian_Sea	378263	329380	48884	311	377952
(4) Laptev_Sea	19790	186004	-166214	235245	-215455
(5) Kara_Sea	235	30387	-30152	15367	-15132
(6) Barents_Sea	0	18890	-18890	4851	-4851
(7) Greenland_Sea	242190	235559	6631	353210	-111020
(8) Baffin_Bay_Gulf_of_St._Lawrence	70138	51991	18148	42247	27891
(9) Canadian_Archipelago	606394	367879	238515	307135	299259
(10) Hudson_Bay	4611	4458	153	1936	2674
(11) Central_Arctic	2852432	3003376	-150944	2626511	225921

The total extent is down 35k km2 (less than 1%) below the 11 year average.  The deficit in Chuckchi is more than offset by surpluses in Beaufort and East Siberian.  On the European side are deficits in Laptev, Kara and Central Arctic, almost covered by the huge surplus in Canadian Arctic Archipelago (CAA).

It’s all good.  It’s natural.

Try To Remember lyrics by Tom Jones from “The Fantasticks”  1960