2013年12月初长江三角洲及周边地区重霾污染的数值模拟

摘要

运用WRF-CMAQ模型模拟了2013年12月1~9日长江三角洲及周边地区的一次重霾污染过程.初步探究灰霾天气下大气细颗粒物(PM2.5)的时空分布特征和区域输送过程，并定量研究了外部源区域输送和本地源对长江三角洲地区 PM2.5的贡献.结果表明：模式能够合理再现灰霾天气下长江三角洲及周边地区 PM2.5的时空分布特征和演变规律.静稳天气下大气细颗粒物仍然存在着显著的区域输送.污染期间来自安徽、山东南部、苏北地区的跨界输送对长江三角洲区域PM2.5的贡献率分别为3.5%~24.9%、0.14%~30.0%、0.03%~17.5%.整个污染期间本地贡献占49%左右，本地贡献和外地贡献基本相当.%A severe haze episode, which occurred over the Yangtze River Delta (YRD) and its surrounding regions from 1December to 9 December, 2013, was investigated using the coupled WRF-CMAQ modeling system. The temporal and spatial distribution characteristics and regional transport process of fine particulate matter (PM2.5) during this episode were investigated. Contributions from regional transport and local emission to PM2.5 concentration over the YRD region were also quantified. Results show that the WRF-CMAQ model could reproduce the temporal and spatial distributions and evolution characteristics of PM2.5 over the YRD its surrounding regions during the haze episode. Regional transport process plays a significant role even under the stable weather situation. During this episode, the contribution percentage of PM2.5 from Anhui, Southern Shandong, and Northern Jiangsu to the YRD region are 3.5%~24.9%, 0.14%~30.0% and 0.03%~17.5%, respectively. Local contribution to the YRD region is equal to the total contributions from outside areas, occupying 49% of the total contribution.