Extended Abstract (996K)14.5
Effects of convective boundary layer inhomogeneities on radar measurements of mean wind and turbulence
Danny E. Scipion, University of Oklahoma, Norman, OK; and R. D. Palmer, P. B. Chilson, E. Fedorovich, and A. M. Botnick
The technique most often used to retrieve the three-dimensional wind (zonal, meridional, and vertical) from wind profiling radars is Doppler Beam Swinging (DBS). This well-known method is based on the assumption of homogeneity across the region defined by the radar beam directions. However, this assumption is not always valid due to the presence of spatial inhomogeneities in the wind field. Given the time needed to complete a typical DBS scan, temporal variability can be a concern. This variability is often on the order of a few minutes.
The present study considers a combination of a virtual radar and Large-Eddy Simulations (LES) to evaluate different wind profiling radar methods of estimating wind and turbulence. Measurements from the DBS method are compared with those from the Spaced Antenna (SA) method, which is a widely used technique that incorporates only a vertical beam for transmission. The backscattered signal is then received using spatially separated antennas. As a result, the SA technique relies less heavily on spatial homogeneity when compared to DBS. For this study, the DBS method was configured for five beam directions (each with a beam width of 9 degrees) in the four cardinal directions with a zenith angle of 15.5 degrees and a vertical beam. Dwell time for each beam was set to 30 s, producing a revisit time of 2.5 min. As ground truth for this study, results from both DBS and SA were compared to the "true" fields obtained directly from the LES.
Session 14, Radar Applications - Session III
Thursday, 15 January 2009, 1:30 PM-3:00 PM, Room 122BC
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