Time to start tracking the Arctic again: Greenland “snow drought” spells trouble

[Junkdrawer]

I think most of us vividly remember last year's events on and around Greenland. It started with albedo going down considerably, causing widespread melt - at one point involving practically all of the ice sheet's surface - ending in a record mass loss of over 500 GT, 2? below the 2003–2012 mean. Just like with the Arctic sea ice, one would expect this record to remain standing this year, but signs so far indicate this is far from a done deal. As I mentioned in the 2012/2013 Winter Analysis temp anomalies in the Greenland and Baffin Bay region were quite positive almost all winter long.

Now Dr. Jason Box reports the following on his Meltfactor blog:

Greenland “snow drought” makes big 2013 melt more likely

A friend in Greenland’s capital Nuuk reported (with a frown) that the backcountry skiing this year was poor due to a “snow drought”.

Multiple melt factors combine to increase the odds of more melt water runoff from the ice sheet during the 2013 melt season:

1.less ‘cold content’ of snow to melt away (ablate) for a given energy input before bare ice is exposed;

2.a longer period of exposed darker bare ice, in this case weeks earlier bare ice exposure is likely unless a big snow dump before or during the coming warm season;

3.Less snow leads to a smaller refreezing capacity in the lower accumulation area. Thanks Robert Fausto of GEUS for reminding me of this one.

4.a possible higher concentration of light absorbing impurities per unit volume of snow, assuming that the impurities are deposited whether or not it snows.

...

We'll have to wait and see what happens when temps go up again and the Sun starts pounding away at the ice sheet. Luckily the entire surface of the Greenland Ice Sheet melts only every 150 years, as we were told last year by NASA's Lora Koenig, so we don't have to worry about that happening again. Excusez le snarque.

http://neven1.typepad.com/blog/2013/05/greenland-snow-drought-spells-trouble.html