Dual-frequency profiler vertical air motions retrieved during TWP-ICE

Poster PDF

Description

Wind profilers are often called “clear-air” wind profilers because they can directly measure the wind motion by backscattering radar energy off of gradients in the turbulent refractive index. This Bragg scattering process enables 50-MHz wind profilers to directly measure the vertical air motion when precipitation is directly overhead. But 50-MHz wind profilers are also sensitive to Rayleigh scattering from raindrops and snow/ice particles that will bias the vertical air motions downward if the hydrometeor motion is not removed from the observed Doppler velocity power spectra. Thus, a dual-frequency profiler technique has been developed that uses the collocated 920-MHz wind profiler observations to identify and mask out the Rayleigh scattering signal in the 50-MHz wind profiler spectra. The poster will present the dual-frequency vertical air motion technique applied to the 50-MHz and 920-MHz wind profiler observations collected during the Tropical Warm Pool–International Cloud Experiment (TWP–ICE). Since the dual-frequency profiler retrievals provide accurate vertical air motion estimates in a vertical column but without any spatial context, these columnar estimates provide a reference measurement for state-of-the-art scanning radar retrievals as presented by the Collis et al. poster.