湖北省一次空气重污染过程的预报分析

Forecasting Analysis on a Severe Air Pollution Process in Hubei Province

针对2016年1月18日湖北省一次空气重污染过程,结合WRF-CMAQ模式、气团轨迹、MODIS真彩图、大气污染物和气象要素监测资料,探讨客观订正环节中区域空气重污染过程的预报方法和基本流程。结果表明:采用WRF-CMAQ模式数值模拟未来3 d湖北省首要污染物及其质量浓度和气象场的时空分布特征和演化过程,预测未来24 h湖北将发生空气重污染过程,结果呈现显著的空间分布特征。气团轨迹和MODIS真彩图分析表明1月17日最严重的霾主要分布在河南和安徽大部地区;途径河南和安徽的气团在未来48 h自北向南往湖北中部和东部传输。根据WRF数值预报,在18日0时弱冷空气南下影响湖北,并带来2～3级偏北风,对大气污染物的输入和积累创造有利的条件,湖北中东部地区空气质量将迅速恶化;至08时后,大气扩散条件有所改善,湖北空气质量将自北向南逐渐好转。

Method and basic process for forecasting regional severe air pollution was studied using the tools including the WRF-CMAQ Model, HYSPLIT（Hybrid Single Particle Lagrangian Integrated Trajectory Model）, and MODIS true color images, as well as the regional monitoring data of concentration of air pollutants and the meteorological parameters. The case in point was a severe air pollution process that took place in Hubei Province on Jan. 18, 2016. The forecasts based on calculation by WRF-CMAQ Model presented the temporal and spatial evolution features of the mass concentration of primary air pollutants and the meteorological field for the consecutive three days（Jan. 17-Jan. 19）, and the severe air pollution process that occurred in Hubei Province within 24 hours starting from Jan. 17, showing the remarkable characteristics of special distribution over the province. According to MODIS true color image and the air mass trajectories, the most serious smog on Jan. 17 occurred in southern Henan Province and the most parts of Anhui Province, and from there the air mass of the smog moving forward to the central and east parts of Hubei Province in the ensuing 24 hours. On the other hand, according to the forecasts by WRF-CMAQ, the south-ward weak cold air mass brought in grade 2-3 north wind which facilitated import and accumulation of air pollutants causing rapid deterioration of air quality in Hubei＇s central and eastern part at 00：00 on the 18 thof Jan;however, after 8：00 the atmosphere diffusion condition began to be improved, thus the air quality of Hubei Province turned better gradually from the north to south.