2011-05-17 16:21:32Arctic ice 2011
Rob Painting
Rob
paintingskeri@vodafone.co...
118.93.14.254

Ice extent has dipped below 2007 again. Be interesting to see what gonna happen this summer.

2011-05-17 16:50:41
Riccardo

riccardoreitano@tiscali...
192.84.150.209

What was exceptional in 2007 is the very rapid melting starting late june. In may the ice extent/area on average decline. We'll see.

2011-05-17 17:25:55
Rob Painting
Rob
paintingskeri@vodafone.co...
118.93.11.128

Indeed, I remember a whacking great high pressure system anchored itself there for a while. What interests me is what effect that continued thinning, and the warming ocean, will have vs the weather this summer.  

2011-05-17 19:02:53
Riccardo

riccardoreitano@tiscali...
192.84.150.209

What's intriguing is the impact of less arctic ice on the weather patterns, but I'm afraid we'll have to wait several years before being able to sort this out.

2011-05-17 20:40:14
Daniel Bailey
Daniel Bailey
yooper49855@hotmail...
97.83.150.37

Yes, a very strong Artic Dipole set in for much of the 2007 melt season.  The result was strong PIPs arrows aiming squarely at the Fram Strait, resulting in an enormous amount of ice advected (flushed out) of the Arctic into the North Atlantic (which means doom for ice so affected).

So while it is technically correct that the 2007 melt season witnessed a great deal of ice melt, not all of it was in the Arctic proper.  The melt seasons of 2001 and 2005 went a long way towards "preconditioning" the multiyear ice towards the Ragnarok that was 2007 (much of the ice advected was MY ice loosened up by the earlier strong melt years).

Keep an eye on Neven's Arctic Sea Ice blog where the ice discussion is very robust:

Monthly extent change

If things continue in this manner, 2011 will soon have the fastest rate of SIE decrease after 2010.

For those with gallows humor (like me), this may be the most fun melt season of all.

2011-05-17 21:24:39
oslo

borchinfolab@gmail...
90.149.33.182

I had a look at the winter temperature anomalis for 2010-2011 compared with 2006-2007 (the winter season before the big melt of 2007).

Seems like the arctic is well prepared for the melting season, with temperatures in large part 1-2 degrees warmer than 2007.

This melting season will be great fun, as Dan put it.

UPDATE (via neven) - article from ScienceDaily:

A preliminary evaluation of the measurement results shows that one-year-old sea ice in the Beaufort Sea (north of Canada/Alaska) is about 20-30 centimetres thinner this year than in the two previous years. In 2009 the ice thickness was 1.7 metres on average, in 2010 1.6 metres and in 2011 around 1.4 metres. "I expect that this thin one-year-old sea ice will not survive the melting period in summer," Dr. Stefan Hendricks assesses the situation.

Looking great!

2011-05-17 23:27:22
Daniel Bailey
Daniel Bailey
yooper49855@hotmail...
97.83.150.37

Yeah, thanks for the news bit, Oslo.  IIRC, First-Year (FY) ice thickness in the Central Arctic Basin is typically about 2.2 to 2.6 meters thick (contrast that to pre-1975 ice which tended to be a mix of 3.5 meter FY and 8-10 meter MY ice [USN submarine-derived data]).  Historically, 1.6 to 1.7 meters of ice (mix of MY and FY ice) melts in each melt season.  If mostly FY ice (like now), 1.9 to 2.0 would be within easy reach.  If, on top of this, a 2007-strength Dipole emerges...all bets are off.

Either way, doom is upon the ice.

2011-05-18 03:39:12
Alex C

coultera@umich...
64.88.86.200

I'm also personally interested in the ensuing effect on the 2011-2012 European winter, this will be a good second (third?) data point to measure against both the lagged heat upwelling hypothesis for a strong Arctic Oscillation, and the low sun activity hypothesis (I think Lockwood 2010, April, covered this topic).

Speculation: assuming that the former hypothesis is true, could increased solar output as the Sun approaches its solar maximum (which will hit in 2013, but still) lead to an even stronger negative AO?  Even aside from large ice melt extent this summer?

Maybe not much, since solar output doesn't vary too greatly between maxima and minima, and it's not even a full amplitude's difference.