Multi-sensor comparison of airflow derived from polarimetric Doppler radars, a UHF wind profiler, and a Doppler wind lidar in the convective and nocturnal boundary layer

This investigation is concerned with the relative accuracy of wind measurements from scanning radars and a 915 MHz radar wind profiler in conditions where biological flyers (BF) are the primary scatterers. Several experiments will be summarized in order to better understand the magnitude of errors in vertical profiles of all three wind components and 3-D airflow derived from three instruments on the MIPS (915 MHz wind profiler - 915, and X-band Profiling Radar - XPR, and a 1.5 μm Doppler wind lidar - DWL) and VAD analyses from X- and C-band dual polarization radars, 3-D retrievals of wind obtained from dual Doppler syntheses (17.5 km baseline), and vertical (particle) motion measurements from the high-resolution XPR. Three interlaced experiments are conducted for both convective and nocturnal boundary layer conditions to examine relative accuracy and quality of estimated airflow: a) Comparison of vertical profiles of horizontal wind derived from the co-located 915, X-band dual polarization radar conducting high-elevations VAD scans, and the DWL conducting VAD scans at identical elevation angles. b) Comparison of vertical velocity from vertically-pointing measurements from the high-resolution (1.3° beam width, 6 Hz sampling) XPR and the DWL (3 Hz sampling). c) Comparison of horizontal winds from dual Doppler syntheses at the location of the 915 and DWL within the “sweet” spot of the dual Doppler network (17.5 km baseline). A key assumption is that the DWL measures the components of the actual wind field (scattering from aerosols), while the X-band, C-band, and UHF radars measure the motion of BF (insects, bats, birds), which is the sum of air motion and the BF motion vector relative to the air. The DWL is assumed to be “ground truth”, an assumption which is validated by vertical wind profiles obtained from a co-located radiosonde, and eventually from wind measurements on a 105 m AGL tower platform located on Redstone Arsenal. Polarimetric measurements from the X- and C-band dual polarization radars will be used to facilitate interpretation of BF types, and related systematic differences between lidar and radar derived wind profiles and vertical motion measurements.