Radar Interferometer Investigations of the Horizontal Winds, Vertical Velocities,Vorticity, and Divergence Around Frontal Zones and in Mesoscale Waves

摘要

Objectives of the research project included the development and testing ofinterferometric radar techniques for measuring horizontal winds, unbiased vertical velocities, refractivity layer thicknesses, and small scale flow and reflectivity gradients. The observational techniques developed in the course of the study were to be used to study the dynamics of gravity and mesoscale waves over Japan. The primary objectives were achieved in a series of experiments using the MU radar with interleaved interferometric and standard multiple beam Doppler measurements. In addition, we found opportunities for two additional technique developments and tests. The first dealt with simultaneous interferometric measurements of precipitation and air motions within the radar beam. The second dealt with frequency domain interferometric measurements of refractivity layer characteristics using a nonaspect sensitive radar operating at 1290 Mhz. Finally, the measured horizontal winds and the vertical velocities corrected for off vertical in beam incidence angles were used to study the dynamics of gravity and mesoscale waves. A major finding of the study was that the wave dynamics are dominated by quasilinear wave breaking instabilities rather than nonlinear diffusive filtering.