大气科学2012，Vol.36Issue(5)：1063-1076,14.DOI:10.3878/j.issn.1006-9895.2012.10205
珠三角城市环境对对流降水影响的模拟研究
A Modeling Study of the Impacts of Pearl River Delta Urban Environment on Convective Precipitation
摘要
Abstract
Using a 2-km-resolution WRF model, along with its single-layer urban canopy model and Thompson bulk-parameterization microphysics scheme, numerical simulation of a convective rainstorm is executed over Guangzhou city in the Pear River Delta (PRD) to investigate the impacts of urban environments (including urban land use changes and urban air pollution-enhanced cloud droplet number concentration) on the convective precipitation. Results indicate that urban heat island and dry island effect produced by the land surface can lead to an enhanced urban boundary layer, which is conducive to air confluence and unstable energy increase in the areas near the city. Simulation shows that to the north and south of Guangzhou city, caused by the urban land surface, there exists respectively a convergence zone with enhanced CAPE (Convective Available Potential Energy) values. The simulated radar echoes being initiated within these zones and consistent well with observations reflect that the urban land surface plays a more direct role in convection initiation and development. Once convection develops, sensitive experiments show that enhanced cloud droplet number concentration might lead to more precipitation. In case with high concentration (polluted cases), precipitation is increased by up to 20%. Diagnostic analysis suggests that the increased precipitation results from that more rain water and supercooled cloud water produce in the convective clouds. These rain and cloud water, carried upward by strong upward motion intensified by more latent heat release during this process, can be transported to higher altitudes, where ice formation is enhanced through freezing or through interaction with other already existing ice species, and that finally results in surface precipitation increase.关键词
对流降水/城市地表/云粒子浓度/数值模拟Key words
convective precipitation, urban land surface, cloud droplet number concentration, numerical simulation.分类
天文与地球科学引用本文复制引用
蒙伟光,李昊睿,张艳霞,戴光丰,万齐林..珠三角城市环境对对流降水影响的模拟研究[J].大气科学,2012,36(5):1063-1076,14.基金项目
国家自然科学基金资助项目40775068,公益性行业科研专项GYHY200706014、GYHY200906026,灾害天气国家重点实验室开放基金2009LASW-B03 （）
