济南市冬季典型重污染天气过程及成因分析

The analysis and causes of typical heavy pollution weather process in winter in Jinan

以山东省济南市2017年12月27-31日的重污染天气过程为例,运用数值模拟与观测资料统计相结合的方法,对此次重污染天气过程的天气形势、气象条件、输送路径和潜在源区进行分析。结果表明:(1)此次重污染天气过程属于静稳累积型污染,基于PM2.5逐时监测数据,将此次污染过程分为污染物累积、重污染持续和显著减弱3个阶段。(2)气压和相对湿度与PM2.5浓度呈显著的正相关,风速则呈显著的负相关,相关系数分别为0.85、0.67、-0.48。地面均压场、持续的小风高湿、逆温等静稳天气有利于污染物的累积与持续。(3)PM2.5输送路径主要为东南和西北路径,分别占轨迹总数的50.71%和49.29%;由于地形原因,东南路径对污染过程的贡献不明显;泰安、淄博等地为此次重污染过程的潜在源区,且以济南市本地污染累积为主。

The heavy pollution weather process from December 27 to 31,2017 in Jinan,Shandong was taken as an example.Based on the combination of numerical simulation and statistical analysis of observational data,the weather situation,the meteorological conditions,transport paths and potential source areas of the heavy pollution weather process were analyzed.The results showed that:(1)the heavy pollution weather process was defined as the meteorological stagnant-accumulated pollution and divided into three stages:pollutant accumulation,heavy pollution continuous and significant reduction on the monitoring data of hourly PM 2.5.(2)There was a significant positive correlation of pressure and relative humidity with PM 2.5 concentration while the wind speed was negatively correlated,and the correlation coefficients were 0.85,0.67 and-0.48,respectively.The static and stable weather such as ground pressure field,persistent breeze,high humidity and inversion were conducive to the accumulation and persistence of pollutants.(3)The PM 2.5 transport paths were mainly the southeast route and the northwest route,accounting for 50.71%and 49.29%of the total number of trajectories respectively.Due to the topography,the contribution of the southeast route was not obvious.Tai’an,Zibo and so on were potential sources and the pollution was mainly local.