Estimation of optical thickness of volcanic ash clouds using satellite data

Radiance measurements within the O2A-absorption band contain information about height distribution of scattering particles. This is widely used for estimation of cloud-top height from satellite data. Within cloud free scenes over the ocean, there is still enough information contained for separation of aerosol loading within the maritime boundary layer and enhanced aerosol loading in the upper troposphere or stratosphere. If stratospheric aerosol content is low, then thin cirrus clouds can be observed. Alternatively, a volcanic ash cloud within the stratosphere or upper troposphere can be investigated after volcanic eruptions. This is demonstrated within this paper by one application example.