Modeling study of a tropical squall-type convective line

Abstract

Two-dimensional model results recapture many interesting features as observed. In particular, the fractional portion of stratiform rain as well as its fractional area coverage are in good agreement with observations. A significant amount of ice particles melted to rain near the freezing level in the trailing part of the modeled squall system during its mature and dissipating stages. The mesoscale circulations above and beneath the freezing level in the stratiform region are also well simulated. Three-dimensional model results could not recapture these features associated with the stratiform region. But explosive growth and a convex-leading edge associated with the convective region are well simulated. The orientation of the three-dimensional simulated convective line is perpendicular to the environmental wind shear as observed. Both of the modeled propagation speeds for the squall systems are in fair agreement with observational case studies. -from Authors