So far this season, melt-out has been very rapid, and currently we're sitting at record low ice extent for the date. Here's a nice figure, courtesy of Thomas Lavergne on Twitter.
The particularly rapid loss this month has been closely related to extreme warmth over Arctic Russia that has persisted more or less continuously since winter, and as a result, current sea ice deficits are strongly concentrated on the Russian side of the Arctic. The latest update from NSIDC is worth a read:
http://nsidc.org/arcticseaicenews/2020/07/siberian-downward-slide/
Here are charts showing the record pace of melt-out this year in the Laptev Sea and the East Siberian Sea. Interestingly, 2012 was not the record low ice year for either basin; in the Laptev Sea the record low occurred in 2014, and for the East Siberian Sea the fastest and most overwhelming melt-out occurred in 2007.
In contrast, the sea ice situation is quite different in the Western Hemisphere, with Beaufort Sea ice in particular holding up well so far compared to many recent years. Both here and in the Chukchi Sea, 2012 was the record low ice year.
An interesting coincidence in the current weather pattern is that a very strong storm has developed over the Chukchi Sea in the past couple of days, just as in early August 2012. The similarity is striking, although the 2012 storm was slightly stronger; compare the Canadian surface analysis maps below:
3pm AKST July 27, 2020
9pm AKST August 5, 2012
The 2012 storm was the strongest summer cyclone of the modern era in the Arctic, and it probably contributed to the record low ice extent that year by breaking up already-vulnerable ice and increasing ice-water mixing. It will be very interesting to see if there are any discernible effects on sea ice from this year's storm.
Here's a reference on the 2012 storm, for further reading:
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2012GL054259
Not the current topic but expect upper air smoke from Siberian fires to affect Alaskan weather - mainly surface temps via reduced insolation.
ReplyDeleteDo prognostic models have a clue about factors influencing insolation? For example the sun in Fairbanks today was a filtered red from the upper layer of smoke.
Gary
Yes, smoke has been clearly visible in the Ester Dome webcam today - perhaps preventing temperatures from moving into the low 80s.
DeleteAs far as I know, none of the global models keep track of smoke, but some regional models do. Here's an example of an Alaska-focused run starting Tuesday afternoon (the link will probably only work for a few days)
https://rapidrefresh.noaa.gov/hrrr/HRRR-AKsmoke/jsloopLocalDiskDateDomainZipTZA.cgi?dsKeys=hrrr_ak_jet:&runTime=2020072900&plotName=trc1_int&fcstInc=60&numFcsts=49&model=hrrr&ptitle=HRRR%20Model%20Fields%20-%20Experimental&maxFcstLen=48&fcstStrLen=-1&resizePlot=1&domain=full
Here's the main forecast menu:
https://rapidrefresh.noaa.gov/hrrr/HRRR-AKsmoke/
Thanks Richard for the HRRR link. Lots of info to explore there but will take some time to appreciate.
DeleteSouth wind yesterday moved the Siberian smoke away from Fairbanks 7/31/20. Finally some summer heat and sun.
Gary
And..over millennia major cooling events have been linked with upper air particles that reduces insolation. They are discharged via surface/subsurface activity like volcanism and fires. Look up the White River tephra and others:
ReplyDeletehttps://www.avo.alaska.edu/about/tephra.php
Gary