哈尔滨市沙尘期大气颗粒物物化特征及传输途径分析

Physicochemical characteristics and long-range transportation of atmospheric particulates during a dust storm episode in Harbin, China

为了研究沙尘期大气颗粒物的物化特征及传输途径,分别采集TSP、PM10和PM2.5样品,分析3种颗粒物的分布特征、浓度变化以及离子和无机元素组成,同时利用HYSPLIT逆轨迹模式对沙尘颗粒的远距离输送来源进行了分析.研究结果显示：沙尘期,PM10∽100是颗粒物的主要组成,占TSP的50%∽57%,PM2.5/TSP和PM10/TSP分别达最低值0.17和0.43;在TSP和PM10中,Na、Si、Al、Ca、Fe、K、Mg浓度变化较为明显,在沙尘期是非沙尘期的2∽3倍,在TSP中的最高浓度分别为7.28、1.98、19.89、25.82、18.77、4.68和6.49μg/m3,以土壤尘和扬尘为主;TSP中Ca2＋、K＋、Mg2＋在沙尘期的浓度是非沙尘期的2∽3倍,最高达22.23、2.04和1.68μg/m3,主要来自土壤、尘埃,与沙尘有相似的来源;逆轨迹模型分析结果表明,本次沙尘事件由外来沙尘输入导致,其传输途径比较明显,起始位置为内蒙古的西北部和中部地区,沿途向南经过山西,后转为东北方向,经过河北、天津、辽宁、吉林等省份,最后输送到哈尔滨.

This study investigates the physicochemical characteristics of atmospheric particulates （TSP, PM10 and PM2.5） during a dust storms episode, including the size distribution of the particles and the chemical composition analysis in particles. In addition, long-range transportation of dust particles is estimated by the HYSPLIT trajectory model to investigate the sources of dust. The results show that PM10-100 is the main components during the dust storms episode and PM10--100/TSP is from 50% to 57%. PM2.5/TSP and PM10/TSP reach the lowest value of 0.17 and 0.43. Na, Si, Al, Ca, Fe, K, and Mg in PM10 and TSP have great variation in dust period and are 2-3 times higher than that in non-dust period with the highest concentration of 7.28, 1.98, 19.89, 25.82, 18.77, 4.68, and 6.49 p.g/m3in TSP. The mass concentrations of Ca2＋, K＋, and Mg2＋ in the dust period are 2-3 times greater than that in non-dust period with the highest concentration of 22.23, 2.04, and 1.68μg/m3 in TSP, mainly from soil and dust. The model results show that dust source in dust period is very obvious which starts at the northwest of Inner Mongolia and central regions, going south through Shanxi to the northeast, passing through Hebei, Tianjin, Liaoning, Jilin and other provinces, and continuously inputting into Harbin.