京津冀中南部污染气象贡献的时空变化特征

Spatial-temporal characteristics of the contributions to the particle pollution meteorological conditions in central and southern Beijing-Tianjin-Hebei(BTH)region

基于环境气象评估指数(EMI,environmental meteorology index),以石家庄、邢台、邯郸、衡水四个京津冀中南部重点城市为研究对象,对2013~2018年的气象条件变化时空分布特征进行分析.结果显示:EMI指数与经过去趋势处理的PM_(2.5)浓度的相关系数达0.88,说明EMI指数具有较好的可靠性,能够可靠性地应用于大气环境评价和重污染天气过程评估业务;基于气象条件对PM_(2.5)浓度贡献的定量分析方法,计算得到2013~2018年月度气象条件对PM_(2.5)浓度变化的贡献率,定量分析不同月份的气象条件变化,可有效评价不同污染程度月份的气象条件影响.此外,该定量方法在重大活动期间气象条件和减排效果评估中得到有效应用;从冬季气象定量贡献的空间分布来看,在京津冀中南部的山前地区形成EMI正距平百分比高值区,除人为排放较高外,恶劣的气象条件是京津冀中南部颗粒物污染严重的重要原因.

In this study,environmental meteorology index(EMI)from model simulation of CMA(China Meteorological Administration)was used to analyze the spatial and temporal distribution characteristics of meteorological conditions variation during 2013~2018 in four key cities of central and southern Beijing-Tianjin-Hebei(BTH)region(Shijiazhuang,Xingtai,Handan and Hengshui).The results showed that,the correlation coefficient between EMI and the detrended PM_(2.5) concentration was up to 0.88.EMI had high reliability,and could be applied to atmospheric environment assessment and the meteorological condition evaluation during heavy polluted processes;the contributions of monthly meteorological condition to PM_(2.5) concentration variation during 2013~2018 were calculated by the quantitative analysis method based on EMI.The influence of meteorological conditions in months with different atmosphere pollution degrees could be effectively evaluated by quantitatively analyzing the monthly variations of meteorological conditions.In addition,the quantitative analysis method had been effectively applied in the evaluation of meteorological conditions and emission reduction effect on PM_(2.5) pollution during important events;According to the spatial distribution of meteorological conditions in winter,it was found that the regions with high positive EMI anomaly percentage concentration were those over central and southern BTH region in front of Taihang-Mountain,which indicated that severe weather conditions were the important reasons for the serious PM_(2.5) pollution in central and southern BTH region,in addition to the high anthropogenic emissions.