摘要
利用全国空气质量指数( Air Quality Index,AQI)、PM2. 5地面观测数据、全球数据同化系统GDAS 数据和FNL 再分析气象资料,研究了2015 /2016 年冬季南京北郊空气质量变化特征以及环境输送条件和污染物源区。结果表明:以AQI 为代表的冬季江淮地区污染程度存在3 种典型的污染物跨区域输送路径—西北路径、北方路径和西南路径。西北路径通常发生在蒙古高压较强,且处于平均位置时刻,南京北郊上空有冷平流,不利于污染物扩散;北方路径对应蒙古高压弱,东北附近为弱高压控制,偏北气流将污染物带至南京北郊,如跨海洋,则污染减弱;西南路径对应南京北郊为边界层内反气旋式环流中心,下沉气流十分不利于污染物扩散。影响南京北郊污染的潜在源区主要分布在河北南部、山东西部、河南南部、安徽东部和湖北西部。河北省是重要的污染源区,河北南部和山东西部污染物通过北方路径输送至南京北郊,因此北方路径虽发生污染概率少于其他两种,却是形成南京北郊严重污染的重要路径。河南南部污染物通过西北路径输送。安徽和湖北污染物通过西南路径输送。定量分析表明,平流输送是南京北郊重度污染的重要原因,近地层风速对AQI 的平流输送占AQI 变化的贡献率超过70%,甚至可达85%。
Based on the national air quality index( AQI), the ground-based PM2. 5 data, the global assimilation system GDAS data and FNL reanalysis meteorological data, this paper studies the variation characteristics of air quality, environmental transport conditions and pollutant sources in the northern suburbs of Nanjing in the winter of 2015 /2016.Results indicate that, represented by AQI, there are three typical pollutant transregional transport routes for winter pollution in Jianghuai area,and they are the northwest,north and southwest routes.The northwest route usually occurs at the time when the Mongolian high is strong and locates at the climatological position.At the same time, there is cold advection over the northern suburbs of Nanjing,which is not conducive to pollutant diffusion. The north route corresponds to weak Mongolian high and weak high near Northeast China.The northerly airflow brings pollutants to the northern suburbs of Nanjing.If it crosses the ocean, the pollutions will be reduced. The southwest route corresponds to the anticyclonic circulation center in the boundary layer in the northern suburbs of Nanjing,and the sinking airflow is very unfavorable for pollutant diffusion.The potential sources of pollution in the northern suburbs of Nanjing are mainly located in southern Hebei,western Shandong, southern Henan, eastern Anhui and western Hubei.Hebei Province is a crucial pollution source area,and the pollutants in southern Hebei and western Shandong are transported to the northern suburbs of Nanjing through the north route. Therefore,although the north route has less pollution probability than the other two routes, it is an important route to form severe pollution in the northern suburbs of Nanjing.Besides,pollutants in southern Henan are transported through the northwest route,and pollutants in Anhui and Hubei are transported through the southwest route.Quantitative analysis shows that the advection transport is an important cause of serious pollution in the northern suburbs of Nanjing.The contribution of near-surface wind speed to AQI advection is more than 70% or even 85%.
作者
黄乾
王海波
HUANG Qian;WANG Haibo(Chongqing Institute of Meteorological Sciences,Chongqing 401147,China;Key Laboratory of Meteorological Disaster,Ministry of Education( KLME) /Collaborative Innovation Center on Forecast and Evaluation of MeteorologicalDisasters( CIC-FEMD) ,Nanjing University of Information Science &Technology,Nanjing 210044,China)
出处
《大气科学学报》
CSCD
北大核心
2019年第4期531-541,共11页
Transactions of Atmospheric Sciences
基金
重庆市气象局开放式研究基金项目(CQM140905)
国家自然科学基金资助项目(41775096)
