基于多源观测数据揭示中国春季沙尘活动的变化及其环流特征  

Revealing the Variations and Circulation Characteristics of Dust Activity over China in Spring Based on Multi-source Observational Data

作　　者：霍彦峰[1,2,3,4] 张脉惠 董自臻 戴晓慧 荀尚培 何彬方[1] 陈心桐[1] 吴文玉 HUO Yanfeng;ZHANG Maihui;DONG Zizhen;DAI Xiaohui;XUN Shangpei;HE Binfang;CHEN Xintong;WU Wenyu(Anhui Institute of Meteorological Sciences,Hefei 230031;Key Laboratory for Atmospheric Sciences&Remote Sensing of Anhui Province,Hefei 230031;Shouxian National Climate Observatory,Huainan 232200;Huaihe River Basin Typical Farmland Ecological Meteorological Field Science Experiment Base,China Meteorological Administration,Huainan 232200;Anhui Public Meteorological Service Center,Hefei 230031;School of Earth Sciences,Yunnan University,Kunming 650500)

机构地区：[1]安徽省气象科学研究所,合肥230031 [2]安徽省大气科学与卫星遥感重点实验室,合肥230031 [3]寿县国家气候观象台,寿县232200 [4]中国气象局淮河流域典型农田生态气象野外科学试验基地,寿县232200 [5]安徽省公共气象服务中心,合肥230031 [6]云南大学地球科学学院,昆明650500

出　　处：《大气科学》2024年第5期1855-1865,共11页Chinese Journal of Atmospheric Sciences

基　　金：风云卫星应用先行计划项目FY-APP-2022.0603;安徽省气象局创新发展专项YJG202203;中国气象局气象能力提升联合研究专项22NLTSY006;中国气象局“量子技术在气象探测中的应用”青年创新团队项目CMA2024QN11。

摘　　要：本文利用1980~2021年MERRA2(Modern-Era Retrospective analysis for Research and Applications,version 2)沙尘资料,结合ERA5大气再分析数据,系统分析了中国春季沙尘的时空分布特征及相关的大气环流异常,结果表明:西北地区沙尘主导了我国春季沙尘的长期变化,二者均具有显著的2~4年和8年以上的周期变化,表现出明显的年际和年代际特征。利用EOF分析表明,EOF1主要体现我国春季沙尘,尤其是西北沙尘的年际变化,在正位相时表现出西北沙尘的显著增加。而EOF2则主要体现我国春季沙尘的年代际变化,在空间上表现为西北与中国其他地区沙尘变化的偶极子特征,其正位相为西北沙尘负异常和其他区域的正异常;在时间上则表现为20世纪90年代末由负转正的位相转变。进一步研究表明,中国春季沙尘变化与气象要素场具有显著的联系:当春季沙尘为正异常时,多为强风控制;此外,较高的地表温度和干旱少雨的背景利于土壤解冻和抑制沙尘沉降,最终造成沙尘天气的发生。此外,影响我国春季沙尘变化的下垫面海温异常表现出类拉尼娜型海温,且海温异常能够从前冬一直持续到同期春季,因此对提前预报春季沙尘变化提供一定的可能性。This study leverages the Modern-Era Retrospective analysis for Research and Applications,version 2(MERRA2)dust data spanning from 1980 to 2021,together with the fifth-generation ECMWF(ERA5)atmospheric reanalysis data,to systematically analyze the temporal and spatial distribution characteristics of spring dust in China and the underlying physical mechanisms driving these patterns.Results show that spring dust activities in Northwest China are the primary drivers of long-term changes observed across the country.These activities exhibit significant periodicities of 2–4 years and beyond 8 years,reflecting clear interannual and interdecadal fluctuations.An empirical orthogonal function(EOF)analysis was employed to identify the dominant patterns of spring dust variability in China.The first EOF mode(EOF1)mainly exhibited interannual variations in spring dust,especially in Northwestern China.The positive phase of EOF1 exhibited significantly increased spring dust anomalies in Northwestern China.By contrast,EOF2 captured pronounced interdecadal variations,displaying an east–west dipole pattern,negative dust anomalies in Northwest China,and positive anomalies in other areas during its positive phase.Notably,an interdecadal phase transition of EOF2 from negative to positive was observed around the late 1990s.Further analysis revealed a strong association between variations in spring dust activities and meteorological conditions.When spring dust levels exceed normal,they are typically driven by strong winds.In addition,high surface temperatures and a lack of precipitation facilitate soil thawing and suppress sand and dust deposition,ultimately leading to increased dust events.Furthermore,La Niña-like sea surface temperature anomalies in the tropical Pacific can affect atmospheric circulation patterns,subsequently influencing dust activities in China.These anomalies,persisting from the previous winter to the following spring,offer potential predictive insights for spring dust activities in China.

关 键 词：春季沙尘 中国西北 大气环流 厄尔尼诺—南方涛动 

分 类 号：P445.4[天文地球—大气科学及气象学]