01 March 2012

The Return of Questions

It's been a long while, but at last here's a question place post for you all to ask about what's on your mind.  Particularly if what's on your mind has something to do with thinks I know about :-)


Hank Roberts said...

how about -- what's going on here?

Kevin O'Neill said...

I'm not sure I completely understand what Chris R is saying over at Dosbat, but looking at PIOMAS volume divided by JAXA Extent vs PIOMAS divided by CT Area yields two similar graphs.

What I find interesting are the dis-similarities. Though post-2009 the curves have become almost identical. That change is also interesting.

Trying to explain the differences has me at a loss. I'm sure some of it has to be data collection methods, but the shapes of the annual curves have changed substantially.

Here's a graph I put together. Arctic Sea ice Thickness

Robert Grumbine said...

Sorry I'm late here.

I'm not sure how much of what dosbat sees in 2010 is a matter of defining seasonal bins (which is mentioned there) and how much is variation between satellite sources, and observation types.

Kevin: Your figure alerted me to a problem at dosbat's. Namely, sea ice thickness is sea ice volume divided by sea ice _area_. Sea ice extent (as dosbat uses) is not the right thing to use. The extent can vary substantially without changing the area. Area is just how much is actually occupied by sea ice.

Extent is what area is behind the ice 'edge' -- including the open water. Anything which tends to increase the fraction of open water in the ice pack, such as divergent wind flows.