My reserach background is in instrument development and field measurements of aerosol optical properties. I and my colleagues have made field measurements of pollution over the Indian Ocean (INDOEX campaign, 1999); at a rural, polluted site in central Illinois (LINC-Bondville campaign, 1999); at a clean coastal site in Hawaii, looking at sea salt (SEAS campaign, 2000); and off the coasts of China, Korea and Japan (ACE-Asia campaign, 2001), studying a mix of pollution and desert dust. Measurements were with TSI, Inc. nephelometers for light scattering at a range of humidities and wavelengths; Particle Soot Absorption Photometers (PSAPs) for light absorption; and a "180degree-backscatter nephelometer", as well as a few tertiary instruments.

The 180 neph instrument development was my PhD work. It measures integrated 176-178degree backscatter by aerosols, which is a good proxy for the 180degee backscatter signal measured by lidar instruments. In order to retrieve light extinction from a lidar one needs to know the extinction-to-backscatter ratio (the so-called "lidar ratio") for the measured aerosols type. Our goal was to characterize the lidar ratio for a range of aerosol types. The data collected during these campaigns is being used in the retrieval algorithms for the recently launched CALIPSO instrument -- a satellite-based lidar.