Automated Monitoring of Volcanic Ash Micro- and Macro-physical Properties: a Comparison of Current and Future Satellite Instrument Capabilities

Introduction Airborne volcanic ash is a major aviation, health, and infrastructure hazard. When ingested into aircraft engines, volcanic ash can cause engine damage or failure. For example, in December 1989, a 747 jetliner carrying 231 passengers encountered an ash cloud during an eruption of the Mount Redoubt volcano, located southwest of Anchorage, AK. Within 60 seconds of encountering the heavy ash cloud, all four engines of the aircraft had stalled. Fortunately, the pilot was able to restart the engines, narrowly avoiding a crash. Volcanic ash is extremely abrasive, and even small concentrations can cause severe damage to the aircraft. In addition, ash falls pose significant health and infrastructure threats to those on the ground. Breathing volcanic ash can result in serious illness or death, and ash falls can also pollute water supplies and damage or destroy buildings. As airborne volcanic ash has significant aviation, health, infrastructure, and economic impacts, frequent observation of volcanic regions and prompt identification of ash clouds are necessary to minimize risk. Geostationary (GEO) and low earth orbit (LEO) satellite data are critical for monitoring volcanic ash clouds. Current satellite-based operational