Chaitén Satellite Views

While checking web discussions of the Chaitén eruption, I have seen many frustrated remarks on the difficulty of obtaining or interpreting satellite views of the volcano. As a long time follower of weather sites, I know a lot of satellite sources, and I have some experience interpreting what the images show.
Even I have been frustrated this weekend. NASA has removed its floater image of the volcano. This is foolish. There are four floaters idle, waiting for tropical storms that are yet to form. It is very rare for four to coexist in the Atlantic Basin, and if this were to happen at all, it would be months from now. The volcano should have priority.
Meanwhile, all one can do is get the full disc image of the Western Hemisphere and click for a comparative close-up. NASA’s GOES East feed was totally down yesterday. Today it’s working again; but at the best of times, it is only updated every three hours — another annoyance. US continental shots update every twenty minutes.
I have blown up a recent sample of a visible image at the top of this post. A small red square indicates approximate location of the volcano. Now we have the problem of interpretation. It is late fall in the Southern Hemipshere. Extremely strong jet stream winds race from west to east in this region. They will continue to do so for many weeks. At midwinter, some Antarctic swirls may move far enough north to shift upper winds in other directions, but we’ll think about that if the volcano is still erupting at midwinter.
You can see extensive mid and high cloud cover in the image. A vigorous mid-level swirl is approaching the coast directly off the volcano. Some ash will probably get borne back over Chaitén town for a few hours this evening as this little storm races ashore. It is the first significant surface wind-shift in this locale since the eruption began, but it will be brief. I presume the volcano is still pluming at mid-levels, but its output is merging with the tide of cloud. It’s impossible to be sure.
Days are short, and it will soon be dark here. Go for the infrared image at night. If any major explosion occurs, it will be easy to see. Look for a burgeoning blob, much higher and brighter than the clouds. It too will move east, but it will spread laterally as well. It will look nothing like meteorological clouds. Let’s hope we just keep seeing jet stream. Already the southern polar vortex has inhaled a lot of SO2.









