The eruption of Pavlof volcano in Alaska’s Aleutian Islands late Sunday was sudden, and produced a massive brown ash cloud as seen in yesterday’s MODIS imagery from NASA’s Terra satellite (click for large version):

The Coast Guard took this photo from one of their aircraft at about the same time as the satellite overpass:

I suspect that it is unlikely that the ash cloud will have much effect on climate due to the relatively small size of the eruption, the high latitude of the volcano, and a probable lack of sulfur emissions into the stratosphere. Tropical stratovolcano eruptions have the biggest effect on climate since volcanic emissions reaching the tropical stratosphere tend to spread over most of the Earth.