Mesoscale divergence profiles from VAD analysis of multiple Doppler radar deployments in the tropics

The profile of inflow and outflow (horizontal wind divergence) in a mesoscale region containing convection is a useful bulk indicator of the diabatic heating profile, and offers clues about scale interaction processes which govern it. An automated VAD analysis has been developed to estimate divergence profiles, with error bars, in a variety of weather situations in which radar scatterers are present. After a brief description of the technique, examples and statistical results are presented which highlight issues of special interest: 1) Reconciling Z-R rainrates with Doppler-estimated inflows of moisture can provide a useful, independent method of calibration. 2) The familiar processes of shallow-to-deep convection transition and subsequent stratiform precipitation are depicted in a robust, objective, statistically significant fashion. 3) Low-level convergence in developing Tropical Storm Ivo was sufficient to ~10-fold the vorticity during an observation interval of several hours. 4) A long-lived propagating convective storm in the Bay of Bengal appears to be coupled to vertical wavenumber 3/2 of the troposphere.

Oral presentation is preferred, and an especially good flow would be to follow this talk with the related work of Zuidema et al.