北京野鸭湖湿地观测站PM_2.5变化特征及其与气象因素的关系

Changing Characteristics of PM_2.5 in Beijing Wild Duck Lake Wetland Station and Its Relationship with Meteorological Factors

摘要: 利用北京野鸭湖湿地观测站2014~2016年PM_2.5和同期气象观测资料，分析野鸭湖地区PM_2.5的变化特征及气象影响因素。研究结果表明：野鸭湖观测站PM_2.5年平均浓度为40 μg•m⁻³，3年来超标比例下降61.6%。PM_2.5污染夏季最轻，春秋次之，冬季最重，各月中PM2.5浓度2月份达到峰值，9月最低。各季PM_2.5日变化大致为双峰型，春冬季更为明显。PM_2.5日均浓度与相对湿度和气压呈正相关，与气温和风速呈负相关，其中与相对湿度相关性最高；各季略有差别，PM_2.5在夏季与气温呈正相关且气压为主导因素，秋季PM_2.5与气压显负相关，其余与日浓度表现一致。野鸭湖地区PM_2.5浓度受本地源和外来源的共同影响，东北风和东北偏东风易造成PM_2.5积累，西南偏西风控制下PM_2.5浓度在各季节中达到最低。

Abstract: Date collected from 2014-2016 was analyzed to study the PM_2.5 concentration and correlated factors in Wild Duck Lake wetland ecological meteorological station. The results showed that the average concentration of PM_2.5 was 40 μg•m⁻³, the exceeding rate of Grade II air quality standards decreased 61.6% over the three years. The seasonal comparison indicated that PM_2.5 pollution was the lowest in summer and heavy in winter. The concentration of PM_2.5 was the highest in January, the lowest in September. The average diurnal variations of PM_2.5 show two peaks, while the characteristic of two peaks was more significant in spring and winter. The daily concentration of PM_2.5 had a positive correlation with relative humidity and air pressure, negative correlation with temperature and wind speed. The humidity was significant factor for PM_2.5. The PM_2.5 concentration was different correlation with meteorological factors in every season. In summer, PM_2.5 had a positive correlation with temperature, meanwhile, the air pressure was the dominant factor. The air pressure had a negative correlation with PM_2.5 in autumn. The remaining characteristics in the seasons were consistent with daily concentrations of PM_2.5. The PM_2.5 in Wild Duck Lake combined impact by local pollution and external pollution. When the station controlled by northeaster and east-northeast can cause more PM_2.5 accumulation, however, the west-southwest has exactly the opposite.