AIRBORNE LIDAR OBSERVATIONS OF LONG-RANGE TRANSPORT IN THE FREE TROPOSPHERE

Two case studies are analyzed to identify probable source regions and mechanisms for material injection into the free troposphere above local mixed layers. An elevated haze/oxidant layer observed over South Carolina on Aug 2, 1980, was found to originate in cumulus convection over Georgia on Aug 1, 1980. An extensive haze/oxidant layer observed over southeastern Virginia on July 31, 1981, is shown to have been in contact with the New England mixed layer on July 30, 1981. This transported air mass is estimated to contribute approximately 30% of the ozone maximum measured at the surface in the Norfolk, Virginia, area on July 31, 1981. Such elevated 'reservoir' layers are transported over long ranges and are not detected by sensors which are confined to the surface.