城市雾霾消散的气象异质性研究

Study on meteorological heterogeneity of urban haze pollution dissipation

利用北京、成都、广州、上海和沈阳5个城市2010-2015年的PM2.5质量浓度和气象逐小时数据,分析了气象因子对这5个城市的雾霾消散过程的影响,及不同城市PM2.5质量浓度对不同气象因素的脉冲响应。结果表明,北京雾霾消散过程主要受风向、露点温度、气压和相对湿度等因素影响;成都雾霾消散过程主要受风向、相对湿度等因素影响;广州雾霾消散过程主要受露点温度等因素影响;上海雾霾消散过程主要受风向、气压和露点温度等因素影响;沈阳雾霾消散过程则主要受相对湿度、风向和气压等因素影响。因此,针对不同城市,根据雾霾发生时的气象特征,环保、气象等部门可联合研究制定最小成本、最理想的减霾方案。

This paper intends to conduct a research on the urban haze pollution dissipation process with the hourly data of PM2.5 mass concentration and meteorological variables of the 5 cities as the information background,which is Beijing,Chengdu,Guangzhou,Shanghai and Shenyang for the years of 2010-2015.Besides the descriptive statistical analysis of PM2.5 mass concentration and meteorological variables in the 5 cities,we have also analyzed the inertia features of PM2.5 mass concentration sequence,which tend to lead to different meteorological dissipation mechanisms of haze pollution through the different meteorological factors in different cities.While most of the meteorological literature documents involved in the haze dissipation mechanism tend to engage in the studies based on the aggregation of the macro data or daily data.It can be found that Beijing dissipates the haze pollution fastest,Shanghai and Shenyang is similar in the dissipation speed,though slower than those of Beijing,and faster than those of Chengdu and Guangzhou.Once the haze weather occurs,it is difficult to dissipate in a short time.Furthermore,we have also traced and observed the specific influence of each meteorological factor on the dissipation process of haze in the above-said 5 cities by analyzing the impulse response of the PM2.5 mass concentration in 5 cities to the different meteorological variables in accordance with the vector autoregressive(VAR)model.The results show that the dissipation process ofhaze in Beijing is mainly affected by the wind direction,the dew point temperature,air pressure and relative humidity,whereas the dissipation process of haze in Chengdu is mainly affected by the wind direction and relative humidity.In comparison,the haze dissipation process of Guangzhou is mainly affected by the dew point temperature,but Shanghai is mainly protracted by the wind direction,the air pressure and dew point temperature.As to Shenyang,it is mainly affected by the relative humidity,wind direction and pressure.Based on the above conclusions of the haze pollution prevention and control work,when the haze weather occurs,the difficulty of haze dissipation in a round can be speculated according to the specific meteorological features of the corresponding cities.The specific meteorological factors mentioned above require more attention.What’s more,the environmental protection and meteorological departments are advised to carry out joint research actions to achieve the most idealistic haze reduction effects at the least economic cost.