郭晓宁,王钰,马秀梅,谈昌蓉,张西营,张吉农,张海潇,陈晶.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[J].环境科学学报,2021,41(2):343-353
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
- Analysis of a typical heavy dust pollution weather in semi-arid region: A case study in eastern Qinghai
- 基金项目：青海省科技厅应用基础研究项目（No.2018-ZJ-723）；2018年青海省省级大气污染防治专项（No.2018015）；青海省气象台2018年科学研究项目（No.2018-03）
- 谈昌蓉
- 1. 青海省气象台, 西宁 810001;2. 兰州大学大气科学学院, 兰州 730000
- 张西营
- 中国科学院青海盐湖研究所, 西宁 810008
- 陈晶
- 青海省黄南藏族自治州气象局, 同仁 811399
- 摘要：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.此外，西风环流将甘肃中部的沙尘传输至青海东部.此次沙尘天气过程地面冷空气在东移南压的过程中，沿河西走廊下滑的冷空气自青海东部河谷地区倒灌进入青海东部，甘肃境内沙尘进入青海后自东向西输送到青海东部，造成青海东部出现重污染天气.逆温层的存在使青海东部大气边界层趋于稳定，不利于污染物向外扩散，无法及时扩散的沙尘长时间维持是导致重污染天气的主要原因.沙尘天气出现前期，青海东部地区湿度条件逐渐变差，沙尘发生前，地面感热明显增加，大气中水汽减少、空气干燥是沙尘天气形成的重要条件.此次沙尘暴传输路径是自东南向西北传播，先后影响海东、西宁两地，与轨迹分析结果一致.
- Abstract：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.
