Mt. Spurr: Radiannet Example

Images from the September 17, 1992 eruption of the Crater Peak vent of Mt. Spurr Alaska. The cloud from this eruption was transported in the jet stream from Alaska, over Canada, the United States, and Greenland.

Note: This data has been posted for collaboration with colleagues at the CMC. Please do not use the data from this page without asking for permission.
Thanks, Dave Schneider (djschnei@mtu.edu)

Silicate Mass Retrieval Maps

Click on the same image to download a larger version.

September 17, 1992

Note that in the first image from 1240 UT, that there appears to be an opaque "core" in the northwest quarter of the image, where the mass could not be retrieved, due to the high optical depth (>4).

September 18, 1992

September 19, 1992

Note that the mass retrievals start to become affected by the background beneath the cloud. Where the cloud passes over Lake Michigan, the mass decreases, due to the warmer background (ie. the retrieval "thinks" that the optical depth is lower, than over a cold background). I would treat all of the mass "patterns" with caution after September 18.

September 20, 1992

Note that the mass retrievals start to become affected by the background beneath the cloud. Where the cloud passes over Greenland, the mass increases, due to the colder background (ie. the retrieval "thinks" that the optical depth is higher, than over a warm background). I would treat all of the mass "patterns" with caution after September 18.

Mass Retrieval Data Files

Click Here to ftp the data files. They are organized as latitude, longitude and silicate mass (in metric tonnes). Note that this is the total mass of silicate in the pixel, which is 64 km^2. For the maps above, I multiply by 1000 to get kg, and then divide by 64 to get kg/km^2.