Infrared radiative transfer calculations for volcanic ash clouds

Radiative transfer calculations are performed for volcanic ash clouds assumed to consist of mixtures of ash particles, ice spheres, water droplets and ash particles coated with sulphuric acid. The results show that for nascent volcanic eruption clouds a reverse absorption effect is noticeable in the infrared window between 10µm and 13µm, for which absorption of infrared radiation increases with increasing wavelength. This effect may be of use in detecting hazardous volcanic clouds from space.

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