Radar Observations of a Plume from an Elevated Continuous Point Source

Abstract

We report on radar observations of a plume of microwave-reflecting chaff. The chaff was released from the top of a 300 m tower and observed as it was blown 18 km downwind through the growing boundary layer. We present the following: 1) a discussion of the advantages and disadvantages of radar-acquired transport and diffusion data; 2) our data on the horizontal and vertical spread of the plume, which we compare with other atmospheric experiments and the tank model results of Willis and Deardorff (1976); 3) axial concentration data that compare favorably with data from an oil fog release at Brookhaven National Laboratories; and 4) peak-to-average concentration ratios that show general agreement with the work of Gifford (1961). These results indicate that radar can provide useful turbulence and diffusion data that cannot be obtained by other means.