半干旱区一次典型沙尘重污染天气过程分析——以青海东部为例

利用常规气象观测资料、颗粒物监测数据,并结合污染源溯源,采用天气学原理和轨迹分析等方法对2019年5月青海东部一次沙尘重污染天气的主要成因及沙尘传输特征进行了分析.结果表明,此次沙尘重污染天气主要由贝加尔湖低槽东移携带的强冷空气沿河西走廊东移下滑,沿湟水河谷自东向西倒灌入青海东部导致,污染物随着强劲的东风影响青海东部....

Analysis of a typical heavy dust pollution weather in semi-arid region: A case study in eastern Qinghai

Based on conventional meteorological observation data and monitored particulate matter data, combined with traceability of pollution sources, the main causes of sand-dust heavy pollution and the characteristics of dust transmission in eastern Qinghai in May 2019 were analyzed using principles of meteorology and trajectory analysis. The results show that the severe dusty weather was mainly caused by cold air carried by eastward Lake Baikal low-slot moving down along the Hexi Corridor, which turned into eastern Qinghai along the Huangshui River Valley from east to west. Pollutants affected eastern Qinghai with strong east wind. In addition, the westerly circulation transfered dust from central Gansu to Eastern Qinghai. The low-slots carry strong cold air moving eastward, leading to heavy pollution in the eastern part of Qinghai. During the dusty weather, the cold air from the Hexi Corridor was poured into the eastern part of Qinghai from the valley. The dust from Gansu Province entered and then transported from east to west to eastern Qinghai, causing pollution. The temperature inversion layer stabilized the atmospheric boundary layerin the eastern Qinghai, which was not conducive to the spread of pollutants. The long-term maintenance of dust that can''t be diffused in time caused heavy pollution. In the early stage of dust weather, the humidity conditions in eastern Qinghai gradually deteriorated. Before the sand-dust occurred, sensible heat on the ground increased significantly. Less water vapor in the atmosphere and dry air were important conditions for the sand-dust formation. The sand-dust was transmitted from southeast to northwest and affected Haidong and Xiningone after another, which is similar with the results of the trajectory analysis.