A global climatology of stratospheric aerosol size distribution parameters derived from SAGE II data over the period 1984–2000: 2. Reference data

Abstract

In a companion paper, a global climatology was presented for different parameters characterizing the size distribution of stratospheric aerosols; the particle number density, median radius, and mode width of the particle size distribution were assumed to be lognormal. Those aerosol parameters were retrieved by optical inversion of Stratospheric Aerosol and Gas Experiment (SAGE) II aerosol extinction profiles. The data cover the time period 1984–2000. In this second part of the study, we present the climatology in a more quantitative way, and starting from the case of the Mount Pinatubo eruption in June 1991, we try to derive reference data for the three considered aerosol parameters. Using four time intervals representative of the different phases of the aerosol relaxation after a major eruption, we investigate the data set spanning the period June 1991 to mid‐1999 and present a spatiotemporal description of the aerosol distribution for the whole relaxation period. The range of the data dispersion due to seasonal effects and random variations is also estimated. Finally, a study of the error on the three parameters is presented for the whole data set, as well as an overview of our validation efforts.