Tropospheric Ozone and Aerosols over the Eastern Tropical Atlantic and West Africa during Summer 2006/Winter 2007: In situ Measurements and Modeling Efforts

This project addresses an important unresolved topic regarding the spatial and temporal distribution of tropospheric ozone over the tropical Atlantic. The goals are to observe tropospheric ozone mixing ratios through in situ measurements, to characterize and quantify aerosol loading and its surface radiative forcing, and to examine the changes in the vertical distribution of ozone during dust events. The data will be obtained from short field intensives during 2006 and 2007, specifically from shipborne measurements during an Atlantic cruise, and from wintertime measurements in a continental environment. The field campaign during the Northern Hemisphere winter in Senegal will examine the direct linkage between winter season dust outbreaks and the vertical distribution and changes in tropospheric ozone. The measurements will include ozonesonde launches from the airport in Dakar, Senegal. The in situ data collected in this study will be compared to satellite derived ozone products and ozone vertical profiles from other stations in the tropical ozonesonde network.

In addition, global and regional meteorological/chemical models will be used in real-time and post-analysis stages for validation against observations and to better understand the chemical and meteorological processes occurring. Measurements from tropical latitudes provide the unique opportunity to examine cross-equatorial transport of biomass burning emissions which enhance tropospheric ozone. Information on the relative contribution of natural sources of ozone (lightning) in the enhancement of upper tropospheric ozone over West Africa and in the outflow region over the tropical Atlantic will be obtained. This work will be carried out in collaboration with scientists at NASA Goddard, as well as collaborators from African Universities.

This project will provide opportunities for an African-American graduate student at Howard University, and a post-doctoral fellow. It will also provide a unique opportunity for close collaboration with West African scientists on the in situ measurements and modeling efforts. This will provide opportunities for both African-American and West African scientists and students to publish in peer-reviewed journals. In addition, these efforts are likely to be of use for other applications in West Africa, such as climate and health matters.

This award is jointly funded with NSF's Office of International Science and Engineering.