PRODUCTION OF DICARBOXYLIC-ACIDS IN THE ARCTIC ATMOSPHERE AT POLAR SUNRISE

An homologous series of low molecular weight dicarboxylic acids (C-2-C -11) have been measured in the arctic aerosol samples collected from J uly 1987 to June 1988 in Alert. Oxalic acid (C-2) was found as the dom inant species followed by malonic (C-3) or succinic (C-4) acid. At the time of polar sunrise, certain dicarboxylic acids in arctic haze aero sols became 5 to 20 times more abundant than in the preceding dark win ter months. Furthermore, they are correlated with tropospheric ozone d epletion events marked by particulate bromine. Here, we report, for th e first time, observations of dicarboxylic acids in the polar atmosphe re and discuss the formation of these organic acids in terms of photoc hemical oxidation of pollutant precursors that reach the Arctic by lon g range atmospheric transport from midlatitudes.