Monitoring Eyjafjallajokull Volcano with GOES-R volcanic ash physical property retrievals

The GOES-R Aviation Algorithm Working Group (AWG) volcanic ash physical property retrievals were performed in near real-time to aid in monitoring eruptions of Iceland's Eyjafjallajökull volcano during Spring 2010. The near real-time retrievals were displayed via the web to aid the London Volcanic Ash Advisory Center (VAAC) in monitoring Eyjafjallajökull. The GOES-R AWG Volcanic Ash team utilizes four Spinning Environmental Visible and Infrared Instrument (SEVIRI) infrared channels (8.5 µm, 11 µm, 12 µm, and 13.3 µm). (Analogous infrared channels exist on the GOES-R Advanced Baseline Imager (ABI)). The AWG ash algorithm first determines which satellite pixels may contain volcanic ash. The ash detection maximizes the sensitivity to cloud composition by accounting for background conditions (e.g. surface temperature, surface emissivity, atmospheric temperature, and atmospheric water vapor). This is difficult to accomplish with traditional brightness temperatures and brightness temperature differences. The satellite pixels determined to contain ash are processed through a three channel (11 µm, 12 µm, and 13.3 µm) optimal estimation retrieval of ash cloud effective temperature, effective emissivity, and a microphysical parameter. These retrieved parameters are then used to estimate ash top height, ash particle effective radius, and ash mass loading. Examples from the Eyjafjallajökull eruptions and validation of the retrieved ash heights will be presented.