基于局地气候区的上海一次高温热浪过程的模拟OA

The Local Climate Zone(LCZ)is a high-resolution urban land use classification.Incorporating LCZ maps as input data into numerical models can provide detailed urban morphological parameters,thereby enhancing the precision of simulations in urban areas.This study focuses on a heat wave event in Shanghai from July 19 to 28,2017,and employs the Weather Research and Forecasting(WRF)model coupled with the LCZ scheme for numerical simulation.Three experimental cases CTL,NOAH,and NOURB were designed to investigate the contributions of land use change and anthropogenic heat to the urban heat island in Shanghai during the heat wave,as well as the impact of urbanization on short-term heavy precipitation.The results indicate that when both urban land use changes and anthropogenic heat emissions are considered,the model successfully reproduces the canopy urban heat island at night and the urban heat island circulation daytime in Shanghai.At night,both land use change and anthropogenic heat positively contribute to the canopy urban heat island intensity,with contributions of 0.89℃and 1.02℃,respectively.During the day,anthropogenic heat contributes positively by 0.27℃to the canopy urban heat island(UHI),while land use change exerts a negative contribution of 0.28℃due to the shading effect of buildings.The simulation of the short-term heavy precipitation process on July 22,2017,in Shanghai found that the presence of cities reduces the convective available potential energy(CAPE)in the lower atmosphere by reducing water vapor and altering temperature vertical distribution,thereby suppressing short-term heavy precipitation in urban areas.The findings of this study contribute to a better understanding of the urban heat island during summer heat waves and provide theoretical insights for addressing potential heat stress from future heat wave events and improving the forecasting capability for small-scale precipitation in urban areas during summer.