THE THERMODYNAMICS OF POLLUTANT REMOVAL AS AN INDICATOR OF POSSIBLE SOURCE AREAS FOR ARCTIC HAZE

The majority of papers on arctic haze have concentrated on chemistry, with some consideration of source areas, synoptic structures associated with transport, trajectory analysis and transport modeling. Very little has appeared on the basic thermodynamics of air with normal humidity, with or without pollutants, traveling into and through the Arctic. When physically reasonable constraints are placed on sources and sinks of heat and water mass and on the relative humidity of near-surface air, it becomes apparent that the assumption of isentropic (adiabatic) flow without precipitation is incompatible with observed water mixing ratios in arctic haze layers. Arctic haze at elevations below 3 km can be explained if precipitation has occurred during transport from the pollution source or if the pollutants were injected from tall stacks into a layer of dry, subsiding air. Haze layers at higher elevations require extreme dryness and relatively high temperatures at their sources, and may be suspected of being of desert origin.