P1.8 a Comparison of Winds Measured by a 915 Mhz Wind Profiling Radar and a Doppler Lidar

Recent work has suggested that it may be possible to extract much higher quality wind information from wind profiling radars than we have traditionally expected. In particular, Gossard et al. (1998) suggested that selection of Doppler spectral peaks by a “human expert” combined with suitable data processing could yield accurate estimates of wind profiles over periods as short as a few minutes. This is in marked contrast to the traditional consensus averaging approach to wind profiler data that yields wind profiles for periods usually no shorter than 30 min. Nearly coincident with that work, the National Center for Atmospheric Research (NCAR) has developed the NCAR Improved Moment Algorithm (NIMA: Cornman et al. 1998; Cohn et al. 2001; Morse et al. 2002; Goodrich et al. 2002), which uses a combination of fuzzy logic and pattern recognition algorithms to emulate peak selection by a human expert. In this paper, we compare profiler winds derived from NIMA processing with those from a Doppler lidar system operated by the National Oceanic and Atmospheric Administration (NOAA). An opportunity for comparison of these systems occurred in October 2000, when the U.S. Department of Energy supported a month-long field study in the Salt Lake Valley. The purpose of the campaign was to investigate the physical processes associated with the dispersion of pollutants in stably stratified urban basins. The Vertical Transport and Mixing (VTMX) field work is described in Doran et al. (2002). As part of this study Pacific Northwest National Laboratory (PNNL) operated a 915 MHz wind profiling radar in the central Salt Lake Valley. During the same period NOAA’s Environmental Technology Laboratory (ETL) operated a Doppler lidar system in a variety of scanning modes. One of these modes was intended to provide a direct comparison with short-term winds from the profiler.