After a post-doctoral position at the National Center for Atmospheric Research (NCAR) with the Advanced Studies Program, Dr. Lefer stayed at NCAR an additional five years working in the Atmospheric Chemistry Division. In 2004, he joined the Department of Earth and Atmospheric Sciences at the University of Houston to study the impact of clouds and aerosols on ozone photochemistry; photochemical reactions occurring within a snow-pack, measurements of industrial emissions; and the relationship between meteorology and air quality. More recently he has started to investigate the health effects of air pollution. In June 2015, Barry Lefer joined NASA’s Earth Sciences Division as the program manager of the Tropospheric Composition Program (TCP).