Zhang Hongliang, Wang Yungang, Hu Jianlin, Ying Qi, Hu Xiao-Ming
Department of Civil and Environmental Engineering, Louisiana State University, Baton Rouge, LA 70803, USA.
Environmental Resources Management (ERM), Walnut Creek, CA 94597, USA.
Environ Res. 2015 Jul;140:242-54. doi: 10.1016/j.envres.2015.04.004. Epub 2015 Apr 13.
Meteorological conditions play a crucial role in ambient air pollution by affecting both directly and indirectly the emissions, transport, formation, and deposition of air pollutants. In this study, the relationships between meteorological parameters and ambient air pollutants concentrations in three megacities in China, Beijing, Shanghai, and Guangzhou were investigated. A systematic analysis of air pollutants including PM2.5, PM10, CO, SO2, NO2, and O3 and meteorological parameters including temperature, wind speed (WS), wind direction (WD) and relative humanity (RH) was conducted for a continuous period of 12 months from March 2013 to February 2014. The results show that all three cities experienced severe air quality problems. Clear seasonal trends were observed for PM2.5, PM10, CO, SO2 and NO2 with the maximum concentrations in the winter and the minimum in the summer, while O3 exhibited an opposite trend. Substantially different correlations between air pollutants and meteorological parameters were observed among these three cities. WS reversely correlated with air pollutants, and temperature positively correlated with O3. Easterly wind led to the highest PM2.5 concentrations in Beijing, westerly wind led to high PM2.5 concentrations in Shanghai, while northern wind blew air parcels with the highest PM2.5 concentrations to Guangzhou. In Beijing, days of top 10% PM2.5, PM10, CO, and NO2 concentrations were with higher RH compared to days of bottom 10% concentrations, and SO2 and O3 showed no distinct RH dependencies. In Guangzhou, days of top 10% PM2.5, PM10, CO, SO2, NO2 and O3 concentrations were with lower RH compared to days of bottom 10% concentrations. Shanghai showed less fluctuation in RH between top and bottom 10%. These results confirm the important role of meteorological parameters in air pollution formation with large variations in different seasons and geological areas. These findings can be utilized to improve the understanding of the mechanisms that produce air pollution, enhance the forecast accuracy of the air pollution under different meteorological conditions, and provide effective measures for mitigating the pollution.
气象条件通过直接和间接影响空气污染物的排放、传输、形成和沉降，在大气空气污染中起着至关重要的作用。在本研究中，调查了中国北京、上海和广州这三个特大城市中气象参数与环境空气污染物浓度之间的关系。对2013年3月至2014年2月连续12个月期间的空气污染物（包括PM2.5、PM10、CO、SO2、NO2和O3）和气象参数（包括温度、风速（WS）、风向（WD）和相对湿度（RH））进行了系统分析。结果表明，这三个城市都面临严重的空气质量问题。观察到PM2.5、PM10、CO、SO2和NO2有明显的季节趋势，冬季浓度最高，夏季最低，而O3呈现相反趋势。在这三个城市中，空气污染物与气象参数之间的相关性存在显著差异。风速与空气污染物呈负相关，温度与O3呈正相关。东风导致北京的PM2.5浓度最高，西风导致上海的PM2.5浓度较高，而北风将PM2.5浓度最高的气团吹向广州。在北京，PM2.5、PM10、CO和NO2浓度排名前10%的日子的相对湿度高于浓度排名后10%的日子，SO2和O3没有明显的相对湿度依赖性。在广州，PM2.5、PM10、CO、SO2、NO2和O3浓度排名前10%的日子的相对湿度低于浓度排名后10%的日子。上海在相对湿度排名前10%和后10%之间的波动较小。这些结果证实了气象参数在不同季节和地质区域差异很大的空气污染形成中的重要作用。这些发现可用于增进对产生空气污染机制的理解，提高不同气象条件下空气污染的预测准确性，并提供减轻污染的有效措施。
