沈阳市沙尘天气特征及与气象因子关系

Sand-Dust Weather Characteristics and Its Relationship With Meteorological Factors in Shenyang

以沈阳市2016~2020年沙尘天气实况监测数据为基础,在分析沈阳市沙尘过程的基础上,对沈阳市沙尘过程的时空分布进行了系统总结,探讨了沙尘过程对环境空气质量的污染程度及沙尘过程中颗粒物浓度变化特征。结果表明:2016~2020年沈阳市发生沙尘过程次数在辽宁中部地区排名第2,在辽宁省排名第3,属于受辽宁省内受沙尘过程影响较大城市;2018年沈阳市出现沙尘过程最多,较2016年增加50%,2019年开始沙尘次数逐年下降。每年3~5月份出现沙尘过程占全年86.2%,且4月份出现沙尘频率最高,占34.5%;其余发生在1月份、2月份及12月份。近5年沙尘过程造成环境空气质量轻度污染、中度污染、重度污染、严重污染小时数分别为243、79、29、82 h,重度及严重污染多集中在3~5月份。沙尘过程中TSP浓度>PM_(10)浓度>PM_(2.5)浓度,沙尘过程较沙尘前后的TSP浓度、PM_(10)浓度、PM_(2.5)浓度上升幅度TSP>PM_(10)>PM_(2.5),沙尘过程对于粒径较大颗粒物较粒径小颗粒物更大。沙尘过程发生频率与气象因子相关性分析显示,风速和相对湿度与沙尘天气频率的相关性较好,且相对稳定;温度与降水量不显著相关。

Based on the actual monitoring data of dust weather in Shenyang from 2016 to 2020,and on the basis of analyzing the current situation of the dust process in Shenyang,the space-time distribution of the dust process in Shenyang is systematically summarized,and the pollution degree of the dust process to the ambient air quality and the change characteristics of the particle concentration in the dust process are discussed.The results show that from 2016 to 2020,Shenyang ranked second in the number of sand and dust processes in central Liaoning Province and third in Liaoning Province,belonging to a city greatly affected by the dust process in Liaoning Province;In 2018,Shenyang had the largest number of sand and dust processes,an increase of 50%over 2016,and the number of sand and dust has decreased year by year since 2019.The occurrence of sand and dust from March to May of each year accounts for 86.2%of the whole year,and the frequency of sand and dust in April is the highest,accounting for 34.5%;The rest occurred in January,February and December.The number of hours of light pollution,moderate pollution,severe pollution and serious pollution of the ambient air quality caused by the dust process in the past five years was 243,79,29 and 82 hours respectively,and the number of extreme serious and serious pollution was mostly concentrated from March to May.The order is TSP concentration>PM_(10) concentration>PM_(2.5) concentration in the sand and dust process.The rising range of TSP concentration,PM_(10) concentration and PM_(2.5) concentration before and after the sand and dust process is TSP>PM_(10)>PM_(2.5).The sand and dust process are larger for particles with larger particle size than for particles with smaller particle size.The correlation analysis between the frequency of dust process and meteorological factors shows that the correlation between wind speed and relative humidity and the frequency of dust weather is good and relatively stable;There is no significant correlation between temperature and precipitation.