Current State of the Arctic Sea Ice: Arctic Sea Ice Predictions

Updated 8/12/11

3:18 pm ET

UPDATE 8/12/11
Despite the negative AO and high pressure, the Arctic has been pretty cloudy (aren't high pressure systems supposed to be mostly cloud-free?) which is probably helping keep melt moderated, though the rate of melt is typically lower in August than the preceding two months.

The sea ice continues to be spread out like a fan all along the western half of the ice pack. The wind patterns seem to be almost opposite of 2007, which is good, because I think if we had 2007 weather we'd be setting massive new records this season. As per this original post, I'm almost certain we'll see new lows in area and volume. I assume being spread out enhances the melt process due to more ice edge being exposed and warming of the sea water underneath from the insolation. The area marked in red is about the same area, +/-, as 2007.

Arctic Sea Ice from MODIS via arctic.io. The red line is the main ice edge; blue is weak "cottage cheese" ice; black is relatively sparse; and yellow is very spread out ice floes.

The ice area and extent have both resumed a more precipitous drop than during the latter half of July. ASI Extent is falling at a slower rate than in spring, but is falling and looks to intersect 2007 extent if trends hold steady, which they shouldn't, of course. The AO may be turning positive or less negative by the end of the month which should slow melt considerably. Still, there are likely five more weeks of melt season remaining. New records are looking more likely.

ASI Area is heading for two million square km less than the reference period.

ASI Volume appears to be/have been setting new records every day this year.

Here's a another nice graph.

My comments posted at RealClimate prior to July 25th seem to still be accurate:

A. If weather is strongly supportive of ice loss, a 100% chance of new minimum in volume, and 95% chance of new minimum area and 90% chance of new minimum extent.

With a negative AO since I said that - though that's not really strongly negative, more like generally or moderately negative - we've seen significant changes in the ice. I'm certain now there we will see a new ice volume low, and think area is edging upward from 95%. I am a little more doubtful of a new extent low unless the wind direction changes significantly and squashes all the ice together - of course, that would also enhance transport out of the Arctic and into the north Atlantic/Greenland Sea, so not a good thing for the health of the ASI - volume and area are better indicators of future conditions, anyway, so a non-record low extent won't mean much.
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I'm amazed at how spread out the ice is, though. This just goes to show that predicting ASI is a lot like picking football games for your favorite team, at least for me: picking individual games, particularly against the spread, is hard, but it's relatively easy to pick the overall season.

The original post is after the jump.

Current State of the Arctic Sea Ice - A Layman's Perspective **Update**

Updated NEP 7/25, NWP 7/24

Note: RealClimate has a very informative open thread on Arctic Sea Ice that is very much worth your time. There are some excellent comments and great links.  


Northeast Passage
UPDATE: Replaced the image with an annotated version; added link to a depth chart for the East Siberian Sea.

Finally, a nearly clear view of the last ice blocking the NEP. (Click for larger image.)

Based on the depth chart found here, it seems hugging the coastline is not a viable option for any large vessels with greater than between 1 - 3 fathoms' draft. This means we can consider the open water open only to vessels with very shallow drafts. All others must go through the ice, but given the 20 mile resolution of this image, that seems realistic, particularly with icebreakers on standby, as would be the case. I wish I had access to someone who navigates the Arctic to see if my thinking is realistic or B.S.

Northwest Passage
UPDATE 7/24 (Scroll down for earlier NWP post.)
It was looking more and more like the southern route of the NWP would open before the northern route, but today it's looking more like a horse race. If you click on the image for a higher resolution you can see significant cracking and deterioration of the ice is occurring in both the main channel and the southern route. The quality of the ice in the southern route appears to be lower than in the northern route. The East-West portion of the southern route is about 350 miles further south than the northern route, so this is not surprising. Passages through the Northwest Passage long ago sometimes had to use the southern route to complete the trip, in fact. If memory serves, the first documented passage of the NWP was through the southern route.