Coastal Circulations and Their Influence on Deposition Patterns in the Washington, D.C. Area

Abstract

The existence of coastal fronts and their effects on deposition patterns in the Washington, D.C. area are presented in this paper. The data are from an experiment conducted from October 1986 to March 1987. An earlier paper by Patrinos et al. presented the details of the deposition patterns. The results presented in that paper were not entirely consistent with the experiment's hypothesis; that is, synoptic-scale southeasterly surface flow would produce excess deposition northwest of the city. Instead, excess deposition was found to the southeast of the urban area. This paper examines the meteorology more closely and shows how small-scale meteorological circulations influence the flow fields and deposition patterns. The wind fields in the experiment area were more northerly to northeasterly in response to coastal circulations, rather than southeasterly as expected from the synoptic conditions. The meteorology and deposition patterns from four cases are presented, with evidence of coastal circulations apparent in three of the four cases.