Conferência Internacional "CIDADES E ALTERAÇÕES CLIMÁTICAS. QUE FUTURO?", Lisboa, 15-16 Maio 2008

Abstract

Major urban development and regeneration have been planned in several regions of the UK and elsewhere. The modification of the morphology of the cities expected in the future poses new challenges in various knowledge fields, from building design and city planning to meteorology. The present work reports an investigation of the effects of urban surface heterogeneity on the distribution of sensible heat flux and its impact on convective precipitation, in Greater Manchester. A simple numerical scheme is formulated to derive fields of surface sensible heat flux for a range of wind and temperature values over the urban area. This involves the derivation and mapping of urban surface characteristics in terms of some morphologic aspects such as the height of buildings and the frontal area index. Comparisons are made of the sensible heat flux field with the rainfall field measured using a C-band radar. The possible influence of the urban morphology on the rainfall distribution, and the eventual initiation of convective cells by the sensible heat flux input generated by the high-rise buildings in Manchester city centre, are discussed.