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 :-)
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.
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.
I'll be trying what seems to be an unusual approach in blogs -- writing to be inclusive of students in middle school and jr. high*, as well as teachers and parents (whether for their own information or to help their children). To that end, comments will have to pass a stricter standard than I'd apply for an all-comers site. It shouldn't be onerous, just keep to the topic and use clean language.
I expect it to be fun for all, however, as you really can get quite far in understanding the world, even climate, by understanding this sort of fundamental. If I get too much less fundamental, let me know where I went astray.
* Ok, I concede that not many middle school students will get everything. Even a fair number of adults will find some parts hard to follow. Still, some middle school kids will have fun. And almost everyone will follow a number of posts just fine.
Please see the comment policy for details. And the link policy for details about that. The latter is more open than you might expect.
In my day job I work on the oceanography, meteorology, climatology, glaciology end of my science interests, but I'm interested in everything, science or not. So I've also been on stage in a production of Comedy of Errors, run an ultramarathon, and been to Epidaurus, Greece, to see a production of Euripides' Iphigenia among the Taurians
Prior to starting the current job, I was a post-doc in oceanography in the UCAR ocean modelling program, and earned my doctorate from the Department of the Geophysical Sciences at the University of Chicago (1989). My undergraduate degree involved Applied Math, Engineering, Astrophysics, and Glaciology.
Of course I don't speak for my employer, whoever that may be.
3 comments:
how about -- what's going on here?
http://dosbat.blogspot.com/2012/03/what-happened-in-spring-2010.html?showComment=1330801415542#c236220563805650470
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
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.
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