Elevated Upper Tropospheric Ozone by Deep Convection during the 2006 Ron Brown Cruise

Biomass burning in Western and Central Africa contributes a significant amount of ozone to the upper troposphere over the Eastern Atlantic Ocean. Mesoscale convective systems are a mechanism that transports ozone and ozone precursors vertically upward and then northward and westward into the Eastern Atlantic. Ozonesonde launches by the Ron Brown Cruise along 23 W during the periods of 11-15 and 26-29 June 2006 recorded elevated ozone in the upper troposphere. Ozone concentrations were greater than 80 DU (or ppb) above 500 hPa during those periods. Here we compare model simulations to observations and examine vertical and horizontal transports of O3 precursors out of Central Africa using the WRF-Chem model. The model has been integrated for the put in actual dates and contains fire emissions from the Global Fire Emissions Database, RETRO Anthropogenic emissions, and MEGAN biogenic emissions. This is the first step towards understanding the relative contribution from anthropogenic versus natural sources (e.g., NOx-lightning or stratospheric/tropospheric exchange) of enriching upper tropospheric ozone.