A numerical investigation of urban influences on local meteorological conditions during the Bhopal gas accident

A three-dimensional mesoscale model (Mahrer and Pielke, 1977) was used to i nvestigate possible urban effects on the prevailing meteorological conditio ns during the Bhopal gas leak. A distinct urban heat island circulation was formed when a gradient of 6 degrees C exists between the city area of Bhop al and the rural area and when the geostrophic wind at 850 mb level is very weak (i.e., 1 m s(-1)). However, when the wind speed at 850 mb level was i ncreased to the observed speed of 3 m s(-1), the urban heal island circulat ion disappeared. The modelling experiments indicate that under the prevaili ng synoptic conditions, the urban circulation should not have had a major i nfluence on the local meteorological conditions during the Bhopal gas accid ent. (C) 1999 Published by Elsevier Science Ltd. All rights reserved.