BostonGeologist on August 8, 2007 - 9:40am
Apropos of several of the featured stories in today's Drumbeat:
The UIUC sea ice page has been discussed here several times before, but the current situation is worth discussing again.
We're within a few days of setting a modern-observations record low for northern hemisphere sea ice extent; 
this is dramatic because we still have more than six weeks of typical melt season to go.
I'm actually a little freaked out by this. I've been watching it for a few weeks, but have hesitated to post because it's always dangerous to sound alarmist based on gut feelings and slivers of data.
Regardless of that, I feel fairly comfortable now stating that we have experienced an entirely new mode of sea ice melt in the northern hemisphere this year. For the first time that we've observed, the melt exposed large areas of open ocean while the artic sea was still exposed to summertime light. That is, in all previous years very little open water in the arctic basin itself was exposed until mid august at the earliest. This year, however, vast swaths of of artic ocean waters were open as early as mid July, when the entire ocean is exposed to 24/7, relatively-high-elevation incident light.
I'm working on a rough-and-dirty simulation of the additional energy input due to this effect this year, but in the meantime:
scroll to animation...
theoildrum.com
Note not only the obvious decrease in area and extent of the main body of ice, but the declines in peripheral ice on the northern coast of Russia and the Canadian Arctic. Hello Northwest Passage...
Please take a look, if you haven't recently, at the UIUC Cryosphere Today page, arctic.atmos.uiuc.edu
and spend sometime convincing yourself that things truly are dramatically different this year. |
