Dynamical and Chemical Structure of the Asian Summer Monsoon Anticyclone in the UTLS

There is much interest in the behavior of the Asian summer monsoon (ASM) anticyclone in the upper troposphere and lower stratosphere (UTLS) due to the role it plays in the vertical transport of chemical species. Recent studies have shown that the ASM anticyclone is an effective transport pathway for chemical species originating from industrial emissions and biomass burning into the UTLS and the horizontal redistribution thereafter. The transport and redistribution of these species into the stratosphere may have significant impact on the climate. One of the outstanding questions is the role of the known quasi-biweekly oscillation of the anticyclone position in redistributing chemical tracers on intraseasonal time scales. The goal of this work is to address this issue by using meteorological analyses and the NCAR Whole Atmosphere Community Climate Model (WACCM) to analyze intraseasonal ASM anticyclone oscillations using geopotential height and the associated effect on chemical redistribution throughout the UTLS using carbon monoxide as a tracer.