Speaker: David Fahey, NOAA, Director of the Chemical Sciences Laboratory
Abstract: Stratospheric aerosols play a central role in Earth's radiative balance and atmospheric chemistry. A variety of sources both natural and anthropogenic influence the background aerosol abundance and cause extreme events. Important examples are volcanic eruptions, space traffic and wildfires. Understanding this central role requires a focus on a variety of sources with stratospheric observations and modeling studies that include chemistry, composition, microphysics, radiation and transport; hence the aerosol nexus. Initiated by Congressional mandate, NOAA’s Earth Radiation Budget (ERB) program was established to study aerosol sources and aerosol processes in the troposphere and stratosphere. ERB includes stratospheric aerosol injection (SAI)—the concept of increasing Earth’s albedo by enhancing stratospheric aerosol—which is emerging internationally as a pressing, albeit controversial, research priority. The Chemical Sciences Laboratory is pursuing fundamental research related to stratospheric aerosols through innovative instrumentation, platform use, observations and modeling, supported in part by the ERB program. I will provide some context to the program and present selected research highlights, including the role of SAI in the Montreal Protocol Scientific Assessment of Ozone Depletion. I am honored in giving this presentation because the guidance and mentoring I received from Professors Anderson, Lin, and Lawler, and the Physics Department, had exceptional influence in my formative years.