Aerosol particle size distribution in the stratosphere retrieved from SCIAMACHY limb measurements

Abstract

w can be retrieved with an uncertainty of less than 20ĝ€%. The algorithm was successfully applied to the tropical region (20°ĝ€N-20°ĝ€S) for 10 years (2002-2012) of SCIAMACHY observations in limb-viewing geometry, establishing a unique data set. Analysis of this new climatology for the particle size distribution parameters showed clear increases in the mode radius after the tropical volcanic eruptions, whereas no distinct behaviour of the absolute distribution width could be identified. A tape recorder, which describes the time lag as the perturbation propagates to higher altitudes, was identified for both parameters after the volcanic eruptions. A quasi-biannual oscillation (QBO) pattern at upper altitudes (28-32ĝ€km) is prominent in the anomalies of the analysed parameters. A comparison of the aerosol effective radii derived from SCIAMACHY and SAGE II data was performed. The average difference is found to be around 30ĝ€% at the lower altitudes, decreasing with increasing height to almost zero around 30ĝ€km. The data sample available for the comparison is, however, relatively small.