Comments on: Snow and Arctic sea ice extent plummet suddenly as globe bakes

By: RobVG

RobVG — Sun, 21 Jul 2013 17:28:54 +0000

That explains it, thanks

By: podrock

podrock — Sat, 20 Jul 2013 23:46:25 +0000

So it is not as significant a factor as compared to a glacier or an ice cap, which are thousands of feet thick. Sea ice extent has a bigger fluctuation than sea ice thickness, so it is a better measure of seasonal change. A few years ago we had the situation where a bunch of sea ice had been pushed by winds into a constricted passage. The news was full of claims that sea ice was getting thicker, but in fact it was a localized effect and did not represent am increase in the system wide volume of ice formation.

We did have a laser range finding satellite up there for a few years:

https://en.wikipedia.org/wiki/ICESat

Good info here:

http://nsidc.org/cryosphere/sotc/sea_ice.html

the following image is from NSIDC:

By: bowser

bowser — Sat, 20 Jul 2013 21:42:32 +0000

Nothing that hasn’t happened before.
Maybe a little faster this time.
Considering that dinosaurs were around for 150 million years or so, and Homo Sapiens Sapiens have managed 50,000 to 75,000, I’m beginning to think that intelligence does not have survival value. We just flatter ourselves that it does, as we merrily foul our nest to the point of approaching uninhabitability.

By: RobVG

RobVG — Sat, 20 Jul 2013 21:11:52 +0000

Thanks n/t

By: RobVG

RobVG — Sat, 20 Jul 2013 21:08:05 +0000

Thanks n/t

By: ER

ER — Sat, 20 Jul 2013 20:55:59 +0000

Volumes have to be modeled, and denialists reject the models, so I normally don’t use them. They are really scary.

As the Arctic warms, the proportion of “old” ice (more than one season’s freezing) is diminishing. The total volume goes down dramatically, but the area loss is more gradual. Still, area is important, and a valuable figure, because even a thin layer of ice reflects sunlight in summer, keeping the underlying water cool. In winter, a thin layer of ice also insulates the water from heat loss just as well as a thick one.

But here is an animation of the PIOMASS model.

http://www.youtube.com/watch?v=YgiMBxaL19M

[youtube id="YgiMBxaL19M" /]

By: TB

TB — Sat, 20 Jul 2013 20:37:51 +0000

The web page I usually refer to also shows “concentration,” one indicator of how thick the ice is. Lower concentrations tend toward chunks with sea between them.

Also, by noting the areas of multi-year ice from one year to the next, or analyzing the speed of freeze-up or melt, a pretty good idea can be arrived at on the thickness of a particular area.

P.S. There are radar and other systems that can measure ice thickness, but most of the ones I’ve heard of are aircraft-mounted. I’m not sure if any satellites are carrying such thickness radars.

By: RobVG

RobVG — Sat, 20 Jul 2013 20:30:10 +0000

Seems like you would need the volume of ice to get a clear picture of what’s going on.