Source Attribution of Aerosols during the Baltimore PM Supersite in 2002 from Lidar, a Turbulence Sensor, and Back-Trajectory Analysis

During the Baltimore PM Supersite experiment highly time and size resolved concentrations of urban PM2.5 and its constituents were collected year round in 2002. Intensive measurement periods were conducted in the spring (March/April) and summer (July 1 - August 15). During those periods a backscatter lidar and a 3D sonic anemometer turbulence sensor provided information on vertical extent of the mixed layer, turbulence characteristics in the mixed layer, and entrainment dynamics. These data together with back trajectory calculations and radiosonde soundings allow good descriptions of the aerosol constituents and source attribution. A total of eleven high PM episodes are analyzed. The Canadian forest fire smoke event of July 6 - 8 is captured in great detail and other exemplary events for coastal air pollution are presented.