Qualitative analysis of input parameters for satellite-based quantification of airborne volcanic ash

Satellite remote sensing data is an important tool to analyze and quantify volcanic ash emissions. However, the algorithms used require a range of input parameters not always known accurately enough for precise calculations. Based on the eruption of Sarychev Peak in the Kuriles, eastern Russia, during June 2009, we analyzed the sensitivity of each of the variables used operationally to evaluate their contributions to the derived mass loading. It is shown that the derived cloud top and surface brightness temperatures, the refractive indices of air and ash, the particle density and the amount of water in the cloud are the dominant factors influencing the retrieval. It is further outlined, how a combination of over- and underestimates of different parameters can yield the same output.