The Vertical Structure of Tropical Urban Heat Island with LES

Abstract

Abstrac t The Large-eddy simulation (LES) model is used to investigate the influence of the Tropical Urban Heat Island (UHI) in the vert ical structure of the Planetary Boundary Layer (PBL) under adiabatic and non-saturated conditions. An idealized UHI is represented by two-dimensional patches of heat fluxes at the surface defining variable Bowen rat io along the horizontal do main. The results indicated that the heterogeneities are able to induce the format ion of intense updraft over the center of warm patch. Th is buoyant thermal transports the mo isture fro m the lower to the upper part of the PBL and penetrate the entrainment zone. Consequently, the urban-breeze circulat ion can contribute to the clouds development at the top of the PBL over the UHI.