Trends and Interannual variability of CO and aerosols in the upper troposphere and lower stratosphere (UTLS): Connection to the Asian summer monsoon dynamics and near-surface pollutant emissions
Dr. Mian Chin
6 Dec, 2 pm
In this presentation, I will discuss the trends and interannual variability of CO and aerosols in the upper troposphere and lower stratosphere (UTLS) during boreal summer that is connected to the Asian summer monsoon (ASM) dynamics and pollutant emission trends. The ASM is a major weather phenomenon in the climate system located over the most populated and polluted regions of South Asia and East Asia. The strong ASM convection lifts surface-generated trace gases and aerosols to the upper troposphere where they further spread out to the east and west by the energetic anticyclonic flow and frequent eddy shedding events. The ASM convection also send pollutants to the lower stratosphere where they can be transported around the globe. In this presentation, I will first show the interannual variability and trends of the ASM anticyclone (ASMA) in the past two decades based on MERRA-2 reanalysis of meteorological fields, and then examine the connections of UTLS aerosol and CO variability and trends to the variabilities of ASMA, convective transport, and pollutant emissions using GEOS/GOCART model simulations and available observations assisted with a suite of diagnostic tracers.