The diagnosis of upper tropospheric divergence and ageostrophic wind using profiler wind observations.

Abstract

Wind fields derived from a network of 3 VHF Doppler radars are used to calculate the mean kinematic properties of the wind field over Colorado and an area-averaged geostrophic and ageostrophic wind. The behavior of the vorticity, divergence, deformation, geostrophic wind and ageostrophic wind are examined for 2 case studies of moderately intense upper-level troughs and jet streams. We find that the computed quantities of divergence, absolute vorticity, deformation, geostrophic and ageostrophic wind are modified by the passage of the weather systems in a manner consistent with our present understanding of upper-level dynamics. In addition, temporal variations are revealed that are beyond the resolution of the existing rawinsonde network. -from Authors