On Wed, 22 Aug 2007 07:59:27 +0100, Graham P Davis wrote in


http://arctic.atmos.uiuc.edu/cryosphere/

There are still a few weeks of melting before the autumn freeze starts.


Any idea why the measurement of the area of ice is so different as that
at NSIDC - 5.26? They both agree it's a record but can't agree on the
value. NSIDC tends to overestimate the amount of ice - it still shows ice
in Hudson Bay and Siberian rivers, for example - but I don't see this as
being enough to account for the difference.

I can only think they are measuring different percentages of ice cover.
Do you have a ready to hand link to what you are seeing at NSIDC, as I
find that site particularly hard to navigate?


Sorry Mike. I'd originally included a link to the relevant page but it got
lost in some re-editing. See
http://nsidc.org/news/press/2007_sea...810_index.html

I found the following hidden away in the NSIDC pages:

"ice extent
the total area covered by some amount of ice, including open water between
ice floes; ice extent is typically reported in square kilometers."

I can only think then that the UIUC site has a higher threshold for ice
cover. They do indicate :" there are some differences between the way we
and NSIDC process our sea ice indices." but don't really elaborate on it.

Whatever the source though, this is a remarkable year. The NSIDC site
usefully goes into the reasons for this year's rapid melt.

--
Mike Tullett - Coleraine 55.13°N 6.69°W posted 22/08/2007 12:06:41 GMT