夏末秋初金沙区域大气颗粒物浓度的变化特征

Variations Characteristics of Mass Concentration in Late Summer and Early Autumn in Jinsha Area

对2013年8-10月金沙区域大气本底站的大气颗粒物观测资料平均日变化和同期的气象资料的平均日变化进行了分析，并与过去的5年同期数据进行对比分析。结果表明：金沙区域夏末秋初大气颗粒物质量浓度有明显的日变化，受气象要素的日变化影响，大气颗粒物质量浓度与相对湿度呈正相关，且颗粒物越小，相关性越强，风向风速对颗粒物质量浓度影响明显，来自观测点北部和东部的气流使大气颗粒物质量浓度升高，而来自西部和南部的风使大气颗粒物浓度降低。受局地排放和气象条件的共同影响，颗粒物质量浓度在凌晨、夜间显著上升。

In this paper,the mean daily variation of air particulate matter from the observational data of August to Oc-tober,2013 and the meteorological data of the same period at the atmospheric background station in Jinsha area are an-alyzed,and the comparative analysis with the data of the same period in the last five years are made. The result indi-cates that there is an obvious daily variation of air particulate concentration in the late summer and early autumn in Jin-sha area. Affected by the daily variation of meteorological elements, there is a positive correlation between air particu-late concentration and relative humidity, that the particulate matter is smaller and the correlation is stronger. Mean-while,the impact of the direction and velocity of wind is obvious. The air flow from the north and south of the obser-vation point makes the air particulate concentration increase, but the wind from the west and east makes it decrease. Affected by local emissions and weather conditions, there is a significant increase in particulate concentration at night and in the early morning.