Arctic ice weirdness
It’s been interesting following the extent of sea ice in the arctic through the year. It seemed at one point as if it was going to break the record minimum set back in 2007, but then in mid July the rate of loss started slowing down, taking it well within the “normal” range. I understand this was due to changing wind patterns, so ice wasn’t being blown southwards as fast into warmer waters. And early in August even seemed to be increasing slightly. However, it appears to have suddenly taken a nose dive - it appears to have lost around a quarter of it’s area almost overnight. Here’s the graph for today (7th August 2011):
Just for fun, for people who read this blog in the future, the graph below is normally updated daily:
Images are from here: http://ocean.dmi.dk/arctic/icecover.uk.php
Very strange. If it keeps going at this rate it’ll all be gone by the middle of next week.
h/t Steven Goddard: http://stevengoddard.wordpress.com/2011/08/07/arctic-to-be-ice-free-by-tuesday/
A possible cause:
That image normally looks something like this:
Comment by Derek Sorensen — August 7, 2011 @ 7:10 pm
http://www7320.nrlssc.navy.mil/hycomARC/navo/arcticicespddrf/nowcast/icespddrf2011080618_2011080700_035_arcticicespddrf.001.gif
The navy is showing a large area of very rapid movement. A long open channel in sync with the orbital period of their satellite could explain it. The definition of “extent” for this graph is 30% concentration or greater. It could be that a large area just went from 30% to 29% due to ice movement. Other concentration graphs show a downturn as well, though not so big.
Comment by vergent — August 7, 2011 @ 8:10 pm
Bizarrely, the Antarctic is doing it too:
Source: http://www.iup.uni-bremen.de:8084/amsr/ice_ext_s.png
So, one of three things is happening:
1) The planet is experiencing a sudden and most definitely unprecedented instantaneous period of warming which is affecting both hemisphere’s equally. Pretty unlikely, I’d say - although if that is what’s happening then it’s unlikely to be due to anything we humans are doing.
2) Something is messed up with a satellite. I don’t know enough about the flight-paths of the satellites involved, but I’d guess they are in an orbit which takes them over both poles, so a messed up satellite could give this effect.
3) Someone has gone wrong with the pixel counting software which is used to estimate the sea ice cover, either: a) there is a long-standing bug which has just appeared due to an edge case, or b) they’ve applied an update which has affected the counting algorithm).
My money is on 3b, although 2 is a possibility. This doesn’t necessarily mean it’s undercounting now - it’s possible it was over-counting before. But either way, it makes it look as though “it’s worse that we thought”.
Hmm. There isn’t an important Climate Conference coming up shortly, is there?
Comment by Derek Sorensen — August 7, 2011 @ 9:54 pm