Thoughts on the ocean, the environment, the universe and everything from nearly a mile high.

Panorama of The Grand Tetons From the top of Table Mountain, Wyoming © Alan Holyoak, 2011

Tuesday, May 22, 2012

So what's happening with the Arctic Ocean melt, May 2012?

The annual Spring-Summer Arctic Ocean sea ice melt is well under way.  Like the past several years, the sea ice extent is below the historical average, though by the end of April the ice extent was still the greatest we've seen for this time of year since 2001.  Even so the NSIDC reported that the rate of ice loss is 2.6% per decade.  In other words...there's less ice up there than there used to be at this time of year, and every year there's getting to be less and less of the the floating white stuff!

The Arctic Ocean sea ice reached its maximum extent in mid to late March of this year.  The only time in the last five years when the sea ice extent was this large this late in the spring was in 2010 when it reached it's maximum in at the very end of March/very beginning of April.

Graph courtesy of the National Snow and Ice Data Center at the University of Colorado at Boulder. (NSIDC).  

The reason the sea ice extent is so large this year is that we have had colder than average conditions in the North Pacific.  The white area on the map below shows the extent of sea ice cover (at least 15% cover) as of 5/21/2012.  The orange lines show the 1979-2000 average extent of sea ice.  

Take a look at the Bering Sea, west of Alaska and north of the Aleutian Islands.  There's a LOT more ice there than usual.  The same thing is true for areas west of the the Kamchatka peninsula by coastal Russia and north of Japan.  In the north Atlantic, however, the melt is near normal by eastern Canada and Greenland.  It's ahead of normal, though, north of Scandinavia and northwest of the Kara Sea.  

I can't imagine that the ice in the north Pacific is going to last that much longer, but we'll just have to wait and see.

The take-home message?  The melt is underway, and though it's been slower than usual for May, it's still melting faster than average over all.

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