TARFOX Abstracts
at AGU Special Sessions
Baltimore, MD, 5/29-30, 1997

John M. Livingston and Philip B. Russell

Aerosol optical depth results derived from measurements obtained during TARFOX with two NASA Ames airborne autotracking sunphotometers will be presented. The Ames six-channel sunphotometer was operated on board the University of Washington C-131A throughout TARFOX and obtained useful aerosol optical depth measurements in four relatively narrow (5 nm full width at half maximum) wavelength bands centered at 380.1, 450.7, 525.3, and 1020.7 nm. During the final few days of the experiment, a newly developed fourteen-channel sunphotometer was operated aboard a modified Cessna airplane (the Pelican) belonging to the Center for Interdisciplinary Remotely Piloted Aircraft Studies. Useful aerosol optical depth data were obtained with the fourteen-channel instrument on July 29 and July 31 in ten separate channels centered at wavelengths between 380 and 1558 nm. Aerosol optical depth spectra, vertical profiles, and horizontal transects will be shown for a variety of low, moderate and high aerosol optical depth conditions that occurred during TARFOX. Examples of aerosol size distributions retrieved from inverting mixing layer optical depth spectra will also be presented. Special emphasis will be placed on results derived from measurements taken with the six-channel sunphotometer on July 25, when a significant latitudinal gradient in aerosol optical depth was measured. The observed gradient amounted to a change in aerosol optical depth of about 0.3 at 525 nm over a 60-km horizontal transect flown at 100 ft MSL.