Analysis of an Asymmetric Doppler Velocity Pattern.
AIR FORCE GEOPHYSICS LAB HANSCOM AFB MASS
Pagination or Media Count:
Plan-view velocity contours of storms are routinely obtained on the color display of the AFGL Porcupine Doppler radar as its antenna rotates in azimuth with a fixed elevation angle. After each azimuth scan the elevation angle is stepped to a new value and a refreshed velocity pattern is displayed. In a widespread stratiform storm the elevated contours of Doppler velocity were remarkably asymmetric, producing a pattern strikingly similar to a Yin-Yang symbol. Fourier analysis of the variation with azimuth of the recorded velocities, however, revealed azimuthal symmetry of velocity components at any given range and elevation angle, indicating at each height an essentially homogeneous wind field which veered appreciably with increasing altitude and displayed a speed maximum well below the top of the precipitation. There were also a number of minor small-scale perturbations superimposed on the major wind field. Author