Wednesday, May 07, 2008

o noes!

All I do is place a modest bet for some warm temperatures and a socking great big volcano goes and erupts. Well at least I didn't put much money on it.

Actually, it's not all doom and gloom. There are several factors that weigh against it really making too much difference to my probability of winning. First, it is not really that big yet, although it may get worse before it gets better. Second, it is at a fairly high latitude (42S) so the plume may not spread over the tropics where it would have most effect. Third, it is going to be winter down there for the next few months so there isn't much sun to reflect anyway. Fourth, these things usually don't have much effect past the first year, and I'd already basically written off 2008 due to the coolish start it's had. By 2009, let alone 2011, it may well be ancient history.

Probably someone is already running some predictions of the effect it is likely to have. I'd try it myself it I had the necessary tools. Of course it's having plenty of effects right now for the people who actually live there.

There are some impressive pictures here and here.


Unknown said...

Does anybody know if this a big enough eruption to bring sulphates to the stratosphere?

James Annan said...

I think it is. Or rather, this link suggests so (together with this one, which was just a random google search). The question is how much and for how long...

C W Magee said...

Can a high latitude winter volcano cause warming by trapping outgoing radiation? Or does that depend on the F, Cl, SO2, etc concentrations?

Whatever climate does, my money is on a whooping great big ozone hole next spring.

C W Magee said...

Also, the smithsonian is now reporting an ash plume height of up to 30 km!

Does the stratosphere have a top?

James Annan said...

Stratosphere goes up to about 50km, with mesosphere, ionosphere, exosphere above. Of course they are not spheres at all, rather spherical shells.

I had wondered about the longwave trapping effect myself. There must be some effect, I'm sure. But it is presumably small compared to the solar shading, since all big volcanoes have historically caused overall cooling. Mind you I don't know how many big high latitude winter volcanoes there have been. Presumably the ash will also darken any snow and ice that it lands on, and warm things up that way. But I'm basically guessing here.

C W Magee said...

"all big volcanoes have historically caused overall cooling"

Don't forget that there will be a reporting bias there, since you don't get high impact journal papers for finding a lack of correlation. IN fact, I think I recall a recent EOS saying that people were using the climate record to look for big eruptions.

If you actually want to look into the possibility of high lat eruptions not cooling, one way of doing it would be to get dates for alaska and kamchatka calderas of appropriate size, then check the appropriate greenland ice cores for ask, S, but no cooling.

C W Magee said...

OK, so I got curious.
Here are some googlicious high latitude eruptions:

Ksudach VEI 6 AD 240 (

Kurile Lake VEI 7 14C age 7618 BP (

Alaska Fisher lake VEI 6 9100BP

Lvinaya Past Kuril Islands VEI 6+ 7480 +/- 50 (note contemporaneous Pinatubo eruption))
Karymsky Kamchatka VEI6 6600BC
Khangar kamchatka VEI 65700BC
Black Peak Alaska VEI 6 1900
Veniaminof Alaskla VEI6 1750bc
Aniakchak 1645BC VEI6
Okmok Alutian 100BC
Churchill Alaska VEI6 60AD
Churchill Alaska VEI6 700AD
Novarupta Alaska VEI 6 jun-oct 1912

1890 BC Cerro Hudson VEI 6 (45S in Chile- analog to current eruption?)
4750 BC Cerro Hudson VEI 6 (45S in Chile- analog to current eruption?)

James Annan said...

Well at least the 1900-ish ones could potentially be visible in the observational record...

David B. Benson said...

The news reports I have read indicate very little SO2 production.

C W Magee said...

If the ash was entrained into the roaring forties, how long would it take to travel ~210 degrees (e.g. just over halfway) around Antarctica?

I ask because we had the most amazingly red sunrise this morning, and there are no fires...

James Annan said...

About 10-12 days, roughly speaking. That is just based on 25mph average wind (here) and a very rough estimate of distance (6500m). So...yes that will be it, I reckon. Enjoy the show (and take some pictures)!