Retrieval of Cloud Water and Water Vapor Contents from Doppler Radar Data in a Tropical Squall Line

Abstract

This paper describes the retrieval of cloud water and water vapor contents from Doppler radar data. The convective part of a tropical squall line (22 June 1981) observed during the COPT 81 (Convection Profonde Tropicale 1981) West African experiment, was chosen for developing a two-dimensional and steady state model for the retrieval of these parameters. The model is based upon the solution of the continuity equation for the total water substance, with wind and rain water fields specified from Doppler radar observations. The results are consistent with the previous kinematic analysis of the convective part of this squall line. Cloud water mixing ratios up to 4 g kg?1 are found in the warm and unstable inflow while unsaturated air is observed in the low level frontward cold flow. At high altitude, an important amount of condensate is transferred rearward into the stratiform part of the squall line. The paper also presents sensitivity tests of the model in order to discuss the main assumptions used to cope with the problem.