On the use of surface equivalent potential temperature in isolating the influence of local as opposed to transported sources on aerosol concentrations

Abstract

An atmospheric aerosol transport hypothesis is presented. An analytical technique, based on an analysis of surface equivalent potential temperature, is used to isolate meteorological conditions that encourage an introduction of transported (advected) aerosols into the surface layer. The difference between the equivalent potential temperature at the surface and 700‐ mbars and the identification of periods of precipitation, are used to define the stability characterstics of the lower troposphere. It is suggested that these three meteorological parameters provide an excellent indication of the horizontal and vertical exchange occurring in the lower troposphere. These parameters, calculated for six upper air sounding stations in North America, are used to isolate those time periods when aerosol populations are most likely influenced by local as opposed to advected sources. Sources of particulate SO4, Al, Se, and crustal corrected V measured at sampling sites in New York State are evaluated with this technique.