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EVIDENCE FOR CLOUD VENTING OF MIXED LAYER OZONE
Citation:
Ching, J.K.S., S. Shipley, AND E. Browell. EVIDENCE FOR CLOUD VENTING OF MIXED LAYER OZONE. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/J-88/327 (NTIS PB89206718), 1989.
Description:
Observations are presented which substantiate the hypothesis that significant vertical exchange of ozone and aerosol pollutants occurs between the mixed layer and the free troposphere during cumulus cloud convective activity. Flight experiments conducted in July 1981, utilized the airborne UV-DIAl, (Ultra-Violet Differential Absorption Lidar) system developed by NASA. his system provides simultaneous range resolved ozone concentration and aerosol backscatter profiles with high spatial resolution. Data were obtained during the afternoon along East to West and South to North intersecting transects over North Carolina in the presence of active, non-precipitating cumulus clouds. vening transects were obtained in the downwind area of the sampled air mass. pace-height cross section analyses for the evening flight show the cloud "debris" as patterns of aerosol and ozone in excess of the ambient free tropospheric background. he ozone excess is approximately the value of the concentration difterence between the afternoon mixed layer and free troposphere measured in the afternoon from independent in-situ vertical soundings made by another aircraft.