Abstract |
The Convective Diffusion Observed by Remote Sensors (CONDORS) field experiment conducted at the Boulder Atmospheric Observatory used innovative techniques to obtain three dimensional mappings of plume concentration fields of oil fog detected by lidar and 'chaff' detected by Doppler radar. It included extensive meteorological measurements and, in 1983, tracer gases measured at a single sampling arc. Final results from ten hours of elevated and surface release data are summarized here. Spatial standard deviations (diffusion coefficients) of chaff and oil agree overall and are consistent at short range with velocity standard deviations and statistical theory predictions. Surface release lateral diffusion is enhanced up to 60% at small distances, consistent with the 1956 Prairie Grass measurements and with larger turbulence velocities and reduced wind speed measured near the surface. Decreased lateral diffusion at small dimensionless averaging times is also noted. Finally, convectively scaled concentrations were plotted versus dimensionless distance and height for oil and for chaff, for each 30-60 min period. Aggregated CONDORS fields compare well with laboratory tank and numerical model simulations. |