Examining Interannual Variability of Tropical Tropospheric Ozone in the RAQMS Aura Chemical Reanalysis

The El Nino-Southern Oscillation (ENSO) is a major driver of interannual variability in both tropical and mid-latitudes, and has been found to have a strong impact on the distribution of tropospheric ozone in the tropical pacific in satellite observational datasets, chemical transport models, and chemistry-climate simulations. These prior studies indicate ENSO-related variability in tropospheric ozone over the tropical Pacific is primarily driven by the changes in the large-scale circulation associated with ENSO. Increased biomass burning emissions associated with ENSO have been found to have a regional influence on ozone column enhancement and less impact on ozone columns away from the source region. Here we present an analysis of interannual variability in tropical tropospheric ozone utilizing the Real-time Air Quality Modeling System (RAQMS) Aura chemical reanalysis. Through use of the RAQMS Aura chemical reanalysis we are able to relate the observed interannual variability in tropospheric ozone concentration to variability in convection, emissions, and net chemical production.