Modification of the Marine Layer over Coastal Southern California

Abstract

The modification and eventual destruction of the marine layer by heating from below is documented by measuring the temperature and humidity fields in a vertical section from the coast of Southern California inland along the trajectory of the air. An instrumented light aircraft is used as the meteorological probe. The base of the temperature inversion near the top of the marine layer is seen to propagate downward into the marine layer as a result of the accumulation of convective debris at the top of the layer. At the inland extremity of the vertical section the marine air is observed to have warmed to the point where convective elements originating at the ground are able to escape the layer and rise into the warm dry air above. Implications of these results on the accumulation and distribution of air pollution are discussed.