2005-12-08

Dunedin: sea ice conf

I haven't blogged much about this conf. Mostly because there is no wireless access (dinosaurs...) but also because much of it is deeply technical sea ice stuff of rather limited general interest. Which is in itself a point of interest: the amount of climate change related stuff is small. A few people have shown the std.pic of Arctic september ice, which shows decline (no-one has shown a similar for the Ant) but only a few people have done anything with it (trying to look at the changes in different ice types: first-yeay, multi-year; but then this is tricky). Also there are only a handfull of papers using climate models.

So what is it actually about? A major theme is sea ice depth (ice fraction is fairly easy (err, thouigh see my brilliant presentation deomonstrating that there are problems even there), depth is much harder). Lots of people are using satellites (radiometer on ERS-2; laser on ICEsat) or helicopter or ship or sfc bourne methods to estimate ice depth. The problem is that while its fairly easy to drill a hole in the ice and measure depth at a point, to get an area value is much harder. EM (electro-magnetic) sensors can detect the water level (on a ship they need to be only 3m above the ice; hung from a helicopter they can be 10 m above the ice, with the heli another 20 m higher up, which apparently makes for exciting flying). So those get you transects. From satellite, you can measure ice freeboard (radar) or top of snow (laser) if you can find enough leads to reference the values to a sea level; this is a major problem. Also measurements from underneath: the late lamented autosub; some stuff from military submarines (their CTDs didn't work so they used the entire sub as a billion pound CTD) which at true cost would be incredibly expensive, but since they are there anyway (not really clear what they *are* doing) they can do some science, even if their sounding kit is a bit dodgy for science.

Apart from that, various things: properties of ice; today a pile of talks about the ice formation mechanism, which isn't really my thing: platelets and congelation and frazil and so on. Special mention for the chap running a molecular simulation of ice formation: with 1,500 molecules his simulation of the 9 ns it takes to freeze took 4 days processing; his value for the freezing temp is 271 (+/- 9) which he regards as extremely accurate. How ice freezes from underneath; new ice dynamics models; measurements from campaigns; etc etc.

Last night we had the conf dinner in Lanarch "Castle" a magnificent but truely fake building, more of a manor house or small chateau. And we had the piping in of the haggis and address to same. And the drinking till midnight.

Note to PH: yes the foxgloves are non-native. But they are lovely.

1 Comments:

Anonymous Steve Bloom said...

Speaking of sea ice, I'm having a little fun over at http://www.warwickhughes.com/blog/?p=20. I hadn't noticed until I started getting into the details a little that this was the very same Coolwire 13 that you had already demolished in part. Willis is quite the guy. I wonder if the rest of his stuff is like that. It will be interesting to see if Warwick is capable of an honest response to this. Obviously he did nothing with your post when you first wrote it, but OTOH I suppose he may not have seen it. Oh, and if don't forget to scroll down to the personal threat in John A.'s comment.

3:38 am  

Post a Comment

Links to this post:

Create a Link

<< Home