Alastair McDonald wrote:
> > There's also some evidence of increased inflow of water from the North
> > Atlantic. The Atlantic water has intruded further into the Arctic
> > Ocean than previously seen. Sorry, I don't have the reference handy.
> > It's all just another nail in the coffin for those that keep saying
> > that there's no global warming.
>
> You are correct again. The lack of growth of winter ice was mainly
> confined to the eastern Arctic bordering the North Atlantic.
> However, if an El Nino does inject warm Pacific into the Arctic,
> then we could see a the ice being attacked on two fronts. This rather
> Maslowski's conclusion "that the Arctic will soon be ice-free in
> summertime."
>
> But more, the winter ice is not regrowing in the eastern Arctic, so
> without a large summer multi-year ice pack, we may find that there
> is no winter ice pack either!
But the extent of sea-ice at the end of the winter freeze season is
still going to be large, even if all the ice melts by the end of the
summer melt period. If all the sea-ice melts, then by definition there
won't be any multi-year ice left. Notice that Comiso's paper discusses
the impacts of winds, which tend to move the sea-ice around to a
considerable degree. The decline seen in the East Arctic Ocean may be
a short term situation, with the winds pushing the ice toward another
part of the Arctic. The important variable, to my mind, is the maximum
extent for the entire Arctic.
Your hypothesis that a complete melt at end of summer would then
produce a complete melt for the entire year is seriously flawed, as the
trends point to a considerable area of ice reforming every year. Also,
I AGAIN wish to point out that there are other impacts of an ice free
Arctic. As the ice area is reduced, the winds will be able to move the
ice and the water in the surface layer much more easily. It would be
very likely that during some year(s), these winds would tend to push
things thru the Fram Strait into the Sub Polar Gyre of the North
Atlantic. This is already occurring and there have been several recent
studies presenting data which suggest that the water in the Sub Polar
Gyre is freshening due to inflow from the Arctic Ocean and melting of
glaciers over Greenland. In my simple minded mental model, I would
expect this freshening to increase in intensity, as the sea-ice area
continues to decline. I see no reason to expect the THC in the GIN
Seas to continue as a result. Without the THC, I would expect to see
winter sea-ice form in the Sub Polar Gyre at latitudes where it also
forms in the Beaufort Sea, since the inflow of warmer water from the
Norwegian Sea would no longer keep the area ice free. Increased flow
thru the Davis Strait into the Labrador Sea from the Canadian
Archipelago could have a similar effect.
In short, I think the data points toward my scenario, not yours.
--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
Global Change ("globalchange") newsgroup. Global Change is a public, moderated
venue for discussion of science, technology, economics and policy dimensions of
global environmental change.
Posts will be admitted to the list if and only if any moderator finds the
submission to be constructive and/or interesting, on topic, and not
gratuitously rude.
To post to this group, send email to [email protected]
To unsubscribe from this group, send email to [EMAIL PROTECTED]
For more options, visit this group at
http://groups.google.com/group/globalchange
-~----------~----~----~----~------~----~------~--~---
