Concentration fluctuations and plume dispersion in the vicinity of an isolated building

In July of 1999, a research campaign was conducted in a rural field near Colfax, Washington, to examine the behavior of pollutants in the vicinity of an isolated structure. Sulfur hexafluoride gas was released at a constant rate near the top of a rectangular building while downwind concentrations were measured with a fast-response analyzer and with syringe samplers. Meteorological conditions were monitored via two uvw anemometers, a sonic anemometer, and a 10-m tower equipped with wind and temperature sensors at two heights. Experiments were conducted during evening and nighttime hours. Processed results will be presented in terms of concentration fluctuations within the recirculation cavity and in terms of time-averaged concentration patterns in the wake regions.