Meteorological analysis of chemical exchange events in the Arctic Basin

Analysis of chemical or aerosol exchange from the troposphere to the arctic surface is considerably more complex than similar analysis of Antarctic events. The complexity of chemical or aerosol exchange experiments in the Arctic requires considering occasional frontal exchange similar to that of the mid-latitudes, potential local contamination, and local sources of heat and moisture. These concerns are eliminated through site selection in most Antarctic exchange experiments. The inherent stability of near-surface layers in the arctic tropopause causes temporal anomalies when arrival times of aerosol or gaseous contaminants are compared with conservative meteorological tracers, further complicating the analysis. Three cases are presented. One illustrates the complexity in analyzing aerosol related to a warming event, the second describes the dimensions of a deep tropospheric mixing in the Arctic Basin, and the third examines the diurnal exchange of aerosol in the arctic summer. Some criteria relative to temporal resolution of aerosol and chemical measurements with respect to meteorological processes are proposed. Potential problems in distinguishing properties of aerosols transported from lower latitudes, in the presence of local aerosol sources, are discussed.