江苏省一次典型沙尘污染过程分析

Analysis of a typicalsand-dust pollution process in Jiangsu Province

2021年4月16日至4月18日江苏省经历了一次受沙尘影响的重污染过程。本次过程沙源地为蒙古国中南部及中国内蒙古中西部地区,在蒙古气旋后部西北大风影响下,沙尘气团自西北向东南影响了中国多个省市和地区。江苏省自16日起逐渐受到沙尘过程影响,苏北城市ρ(PM_(10))从凌晨开始迅速升高,浓度最高达569μg/m^(3),空气质量达严重污染级别。17日,受蒙古气旋后部冷高压带来的偏北风影响,沙尘气团位置明显南移,多数沿江城市PM_(10)开始上升,空气质量达中度污染级别。至17日夜间,本次影响江苏省的沙尘过程基本结束。沙尘影响期间,江苏各市不仅ρ(PM_(10))浓度快速上升,同时ρ(PM_(2.5))/ρ(PM_(10))比值也明显下降,由受沙尘影响前的介于0.60~0.75之间迅速降至介于0.15~0.23之间。

From 16 to 18 of April 2021,Jiangsu Province suffered a severe air pollution impacted by sand-dust process.The source of the sand in this process is the central and southern Mongolia and the central and western Inner Mongolia in China.Under the influence of the strong northwest wind behind the Mongolian cyclone,the sand and dust masses affected many in China from northwest to southeast.The sand and dust process has gradually affected Jiangsu since 16 April 2021,the PM_(10) of the cities in northern Jiangsu has risen rapidly from the early morning,up to the maximum 569μg/m^(3),and the air quality was in a serious pollution level.On the 17 April,affected by the northerly wind brought by the cold high pressure behind the Mongolian cyclone,the dust air mass moved to the south obviously.The PM_(10) of most cities along the Yangtze River began to rise,and the air quality of these cities reached a moderate pollution level.By the night of 17 April,the sand and dust process affecting Jiangsu was almost over.During the period of sand and dust,not only did the concentration of PM_(10) rise rapidly in cities of Jiangsu,but the ratio of PM_(2.5)/PM_(10) also decreased significantly,from 0.60-0.75 before the sand and dust process,to 0.15-0.23 during the process.