Seasonal to decadal variability of aerosols in the upper troposphere and lower stratosphere and its connection to anthropogenic and natural sources and multi-scale transport process

We present our study of seasonal to decadal variability of UTLS aerosol composition and their trends in terms of sources, transport mechanisms, and aerosol-meteorology interactions through modeling and analysis of observations. We use the NASA global model GEOS that incorporates emissions from anthropogenic, biomass burning, volcanic, and other natural sources to simulate the aerosols and track their origins. The model results are compared to satellite observations for the time period of 2003-2018. We examine the relationship between the UTLS aerosol concentrations and the subseasonal variability of convection, interannual variability of Asian monsoon strength, and trends in surface pollutant concentrations. Finally, we will estimate the stratospheric aerosol optical depth and contributions from tropospheric sources, volcanic eruptions, and background aerosol from carbonyl sulfide oxidation in the stratosphere.