Connecting Lightning to Chemistry Over Central Africa

The goals of this project are to use satellite imagery and data to (1) develop a lightning climatology for West and Central Africa, (2) to compare this climatology with images of savanna fires and regional biomass burning and column ozone, and finally (3) to combine these analyses with model estimates of in situ production and transport of ozone to determine the link between lightning activity and elevated ozone levels in the southern hemisphere troposphere.

Data from the Lightning Imaging Sensor (LIS) aboard the Tropical Rainforest Measuring Mission (TRMM) satellite will be used to correlate lightning to mesoscale convective systems (MCSs) and used to estimate monthly NO production rates. Data from the Total Ozone Mapping Spectrometer (TOMS) and from the Advanced Very High Resolution Radiometer (AVHRR) will also be used to obtain near coincident information on column ozone and biomass burning in the region. By combining model and satellite estimates of transport, an improved understanding of the interplay between in situ natural production, transport, and biomass burning influence the tropospheric ozone balance in the southern hemisphere can be obtained. This research seeks to exploit the unique opportunity to use a combination of satellite data to critically examine lightning climatology over one of the most lightning-active regions in the world and its influence on the chemistry of the regional troposphere relative to other natural and anthropogenic phenomena. The specific outcomes of this work are the characterization of lightning activity in MSCs observed in Central Africa as a function of frequency, intensity, spatio-temporal evolution and distributions, and to provide a first principles estimate of the NOx production of lightning over Central Africa.

This poster will focus on a discussion of the chemical model for NOx production and a lightning climatology for the Central African Basin using TRMM LIS data.