"Approved by: Robert S. Leonard, Executive Director, Geoscience and Engineering Center." Prepared for: Atmospheric Sciences Research Laboratory, U.S. Enviromental Protection Agency, Research Triangle Park, North Carolina. "SRI Project 8927." "Final Report." "February 1987." Includes bibliographical references (p. 19) "DocNo."

Airborne lidar observations of fluorescent dye particle (FDP) tracers were made at Lexington, Kentucky, during August 1985 in support of the VENTEX '85 field program. Most of the FDP experiments were concerned with transport and diffusion of the FDP in clear-air regions surrounding convective clouds. FDP releases were made at various altitudes relative to cloud base and top, and with respect to wind direction in the cloud layer. In all cases, FDP released in the cloud layer moved away from the convective cloud and centered in the clear-air regions between clouds. Any downward transport of FDP was of a lower concentration than could be observed with the airborne lidar. Therefore, a coordinated remote and in-situ tracer measurement program is recommended for future study of pollutant exchange between the cloud and near-surface mixed layer. The use of two airborne lidar systems facilitated the mapping of FDP distributions in the cloud layer over extended time periods of about eight hours. A data example is presented that indicates the importance of the Appalachian Mountain influence on long-range transport and diffusion. An airborne lidar/FDP experiment is suggested to investigate elevated air flow and FDP surface impaction across the Appalachian Mountain regions.