山东惠民黑碳气溶胶变化特征及来源分析

Variation characteristics and source analysis of black carbon aerosols in Huimin,Shandong

利用山东惠民国家基准气候站2018年12月-2019年11月的黑碳质量浓度、常规气象观测资料以及GDAS数据,研究了该地区黑碳气溶胶的变化特征,并基于后向轨迹模型对其潜在源区进行了分析。研究结果表明:1)观测期间,黑碳质量浓度平均值为3.22μg·m^(-3),季节变化呈冬、春季高,夏、秋季低的特点;春、夏、秋季黑碳质量浓度的高频值在2μg·m^(-3)以内,冬季的高频值在6μg·m^(-3)以上。2)黑碳质量浓度日变化呈双峰结构,峰值分别出现在06:00-08:00和19:00-21:00,谷值出现于13:00-15:00。3)降雨和风对黑碳质量浓度有明显影响。非降雨期黑碳质量浓度是降雨期的2.8倍;当风速小于3 m·s^(-1)时,黑碳质量浓度随风速增大而减小;冬季在西南西方向、春季在正南方向过来的气团易造成黑碳质量浓度高污染。4)惠民气流输送的季节变化特征明显。春、秋、冬季来自鲁中、河北和苏北等周边地区的气流所占比例较高,对应黑碳质量浓度高值;夏季来自海洋方向的气流占比较高,对应的黑碳质量浓度较低。

Utilizing the black carbon mass concentration and conventional meteorological data of the national reference climatological station in Huimin,Shandong,and GDAS data from December 2018 to November 2019,the variation characteristics and potential sources of black carbon aerosols are analyzed based on the TrajStat model.The research findings are shown below.1)During the observation period,the average value of black carbon mass concentration is 3.22μg·m^(-3),and the seasonal variation presents the characteristics of high in winter and spring,but low in summer and autumn;the high-frequency value of black carbon mass concentration in spring,summer,and autumn is under 2μg·m^(-3),while above 6μg·m^(-3) in winter.2)The diurnal variation of black carbon mass concentration has a bimodal structure,of which the peak value appears from 06:00 to 08:00 and from 19:00 to 21:00 and the valley value appears from 13:00 to 15:00.3)The black carbon mass concentration is obviously influenced by rainfall and wind.The average value of the non-rainy period is 2.8 times that of the rainy period;when the wind speed is under 3 m·s^(-1),the black carbon mass concentration decreases with the increase of wind speed;the air mass coming from west-southwest in winter and from due south in spring is liable to cause high pollution of black carbon mass concentration.4)The seasonal variation of air flow is obvious in Huimin.The air flow from the surrounding areas such as the central Shandong,Hebei,and the north of Jiangsu takes a high proportion in spring,autumn,and winter,corresponding to high black carbon mass concentration;while the air flow from the ocean takes a high proportion in summer,corresponding to low black carbon mass concentration.