Typical Cases

• El Chichon: April 4, 1982
• Klyuchevskoi: October 1, 1994

Exceptions to the Rules

Positive Volcanic Clouds

• Opaque Volcanic Clouds
• Ice/Water Coatings on Ash
• "Warm" cloud over "cold" background

Negative Meterological Clouds

• "Warm" cloud over "cold" background

Complications

Inhomogeneous Background

• Mt. Spurr: September 19, 1992

Geostationay Satellite Examples

• GOES-8: Popocatepetl, Mexico
• GMS-5: Ruapehu, New Zealand

North Pacific Eruption Examples

• Augustine, Alaska: 1986
• Redoubt, Alaska: 1989-90
• Crater Peak/Spurr, Alaska: 1992
• Klyuchevskoi, Russia: 1994