2021年和2022年春季中国北方地区沙尘气象因素和沙源地条件异同  

Comparative analysis of meteorological factors and sand source conditions in sand and dust weather events in northern China during the spring of 2021 and 2022

作　　者：吴进 李琛 朱晓婉 邱雨露 唐宜西 马小会 WU Jin;LI Chen;ZHU Xiaowan;Qiu Yulu;Tang Yixi;MA Xiaohui(Beijing Weather Forecast Center,Beijing 100097,China;Beijing Meteorological Service Center,Beijing 100089,China)

机构地区：[1]北京市气象台,北京100097 [2]北京市气象服务中心,北京100089

出　　处：《大气科学学报》2023年第6期950-960,共11页Transactions of Atmospheric Sciences

基　　金：国家自然科学基金资助项目(42207115);北京市自然科学基金资助项目(8204075)。

摘　　要：2021年春季中国北方地区共出现了4次沙尘暴或强沙尘暴,2022年同期仅出现1次沙尘暴。基于2015—2022年空气质量和多源气象数据,利用Lamb-Jenkinson分型法与Mann-Whitney U检验法开展了2021年和2022年春季沙尘源地条件和气象因素异同分析,得到以下结论:中国北方沙尘天气多发型分为NW-N型(气旋型)和E-NE型(高压型),NW-N型造成的PM_(10)极值更高、高浓度范围更广。气象因素而言,2022年春季有利于沙尘的天气型活动更频繁,与2021年春季沙尘日PM_(10)浓度差异主要集中在NW-N型,两段时期NW-N型活动频数、气旋强度接近,有利于沙尘天气的动力抬升条件接近。从沙源地条件而言,2021年前冬蒙古沙源地土壤温度“前冷后暖”导致融雪等水量峰值早至,加之大面积降水负距平且3月蒙古沙源地气旋偏强,干燥、稀松的沙源致使春季沙尘多发;2022年前冬蒙古沙源地土壤气温“前暖后冷”导致融雪期等水量、土壤含水量峰值晚至,深厚湿润的土壤条件不利于起沙。故蒙古沙源地条件差异是两个时期沙尘差异显著的主要原因。Northern China experienced four sandstorms or severe sandstorms in spring 2021,contrasting with just one event in the corresponding period of 2022.Utilizing air quality and multi-source meteorological data spanning 2015 to 2022,we applied the Lamb Jenkinson classification and Mann-Whitney U test methods to analyze similarities and differences in the sand source areas conditions and meteorological factors during the spring of 2021 and 2022.Our findings reveal that the sand and dust weather(SDW)in northern China is frequently categorized into NW-N(cyclone type)and E-NE(high-pressure type),with the NW-N type leading to higher PM_(10) extreme values and a broader range of high concentrations.In terms of meteorological factors,synoptic conditions favorable for SDW in spring 2022 occur more frequently,with the differences in daily PM_(10) concentration predominantly associated with the NW-N type when compared to spring 2021.The frequency of NW-N type events and cyclone intensity remains comparable between the two periods,along with similar dynamic uplift conditions conducive to SDW are similar.Regarding sand source area conditions,the soil temperature in Mongolia s sand source area displayed a“cold before and warm after”pattern in the pre-winter of 2021,resulting in an early peak of snowmelt and other water content.In addition,a widespread decrease in precipitation and a relatively strong cyclone in Mongolia s sand source area in March contributed to the high incidence of sand and dust in spring 2021.Conversely,during the pre-winter of 2022,the soil temperature in Mongolia s sand source area followed a“warm before and cold after”trend,leading to a delayed peak of water content and soil moisture content during the snowmelt period.These conditions,characterized by thicker and moisture soil,were less conducive to sand formation.Therefore,the disparities in Mongolian sand source area conditions represent the primary factor behind the significant differences in SDW between the two periods.

关 键 词：沙尘 PM_(10) 天气分型 沙源地 

分 类 号：P425.55[天文地球—大气科学及气象学]