国家重点研发计划重点专项项目 2016YFC0203304 ; 国家自然科学基金重大研究计划项目 91544109 国家重点研发计划重点专项项目2016YFC0203304，国家自然科学基金重大研究计划项目91544109
本文利用中尺度模式WRF（V3.9）对2016年12月7日成都东部（龙泉山）一次污染过程下的山地—平原风环流进行了模拟，旨在探讨冬季污染天气下山地—平原风环流的结构和演变特征。此外，通过减少气溶胶光学厚度（AOD，Aerosol Optical Depth）的敏感性试验探究气溶胶污染对山地—平原风环流的影响。结果表明：冬季污染大气条件下成都平原地区存在显著逆温。龙泉山南北长、东西窄且高度较低，由于东、西坡辐射能量的不均匀分布和背景风的强迫，上午、凌晨和夜间均出现越山下坡风环流，上午强度较强，凌晨和夜间强度较弱。午后开始出现平原风环流，最大影响范围为山体宽度的3～4倍，17:00（当地标准时，下同）左右结束。各阶段环流在南北方向上差异较大，越山下坡风环流在南段最强，中段最弱；中、南段山体较低窄，平原风环流易被湍流掩盖，北段平原风环流最为明显。AOD减小后辐射及地表热通量均有所增加，中、南段湍流更加旺盛，边界层显著抬升且降低时间滞后，山体与平原间感热通量差异增加，北段平原风环流增强、持续时间增长。
In this paper, WRF (V3.9) is used to simulate the mountain-plain breeze circulation in eastern Chengdu (Longquan mountain) during a heavy pollution event on 7 December, 2016. The structure and evolution of the mountain-plain breeze circulation are discussed. Besides, the influence of the Aerosol Optical Depth (AOD) on the mountain-plain breeze circulation is examined by conducting a sensitivity experiment in which the AOD value is reduced. The Longquan mountain is fairly long from north to south and relatively narrow from east to west with low elevation. Results show that strong ground inversion existed in the winter during the heavy pollution event. Cross-mountain downslope wind circulation occurred in the night and late morning due to the imbalance of radiative heating between western and eastern slope and the dynamic forcing of background wind. The plain breeze began after the noon and ended at around 1700 LST. The maximum horizontal stretch of the plain breeze circulation could reach 3 to 4 times of the mountain width. Cross-mountain downslope wind circulation and mountain-plain breeze circulation varied greatly in the north-south direction. The former was stronger in the southern part of the mountain whereas the latter in the central and southern part was easily covered by vigorous turbulence. In the northern part, on the contrary, there existed significant plain breeze circulation. After reducing the AOD in the sensitivity experiment, the solar radiative heating and planetary boundary layer height both increased to a certain extent. Plain breeze circulation in the central and southern part became more ambiguous due to amplified turbulences. In the northern part, plain breeze circulation enhanced and lasted longer due to the elevated planetary boundary layer and the strengthened difference in sensible heat flux between the mountain and plain areas.
田越,苗峻峰,赵天良.污染天气下成都东部山地—平原风环流结构的数值模拟.大气科学,2020,44(1):53~75 TIAN Yue, MIAO Junfeng, ZHAO Tianliang. A Numerical Simulation of Mountain-Plain Breeze Circulation during a Heavy Pollution Event in Eastern Chengdu. Chinese Journal of Atmospheric Sciences (in Chinese),2020,44(1):53~75复制