2022年5月广东气温异常偏低的气候特征及其成因  

On the Climatological Characteristics of Anomalously Lower Air Temperature in Guangdong in May 2022 and Its Causation

作　　者：谢洁宏 胡娅敏[2] 叶梦茜 XIE Jie-hong;HU Ya-min;YE Meng-qian(Meteorological Bureau of Jieyang,Jieyang 522000;Climate Center of Guangdong Province,Guangzhou 510640)

机构地区：[1]揭阳市气象局,广东揭阳522000 [2]广东省气候中心,广东广州510640

出　　处：《广东气象》2024年第1期19-22,27,共5页Guangdong Meteorology

基　　金：广东省基础与应用基础研究重大项目(2020B0301030004);中国气象局创新发展专项基金(CXFZ2023J027);中国气象局预报员专项(CMAYBY2020-094)。

摘　　要：基于NCEP/NCAR再分析数据集、NOAA海温和向外长波辐射以及国家气象观测站平均气温数据,采用线性趋势、合成分析方法,探讨2022年5月广东气温异常偏低的气候特征及其成因。结果表明,2022年5月平均气温较常年低1.9℃,创下广东1961年以来最低值;该次异常低温是在拉尼娜事件背景下发生的,通过大气环流对欧亚大陆气候产生显著性影响;欧亚中高纬环流经向度偏大,东亚大槽与蒙古高压偏强,引导东西伯利亚及其以北地区过多的冷空气向南侵袭,同时低纬活跃的偏南暖湿气流与北方冷空气在广东上空交汇致雨成云,地表非绝热加热与大气下沉增温效应受抑制,进而导致了2022年5月的气温异常偏低。Based on the reanalysis datasets of NCEP/NCAR,the SST and outgoing longwave radiation data of NOAA and the average temperature data from national meteorological observation stations across Guangdong,this work analyzes the climatological characteristics of the province’s anomalously lower temper-ature in May 2022 and its causation using the methods of linear tendency and composite analysis.The results are shown as follows.In May 2022,the monthly average temperature of Guangdong was 1.9℃lower than u-sual,becoming the lowest provincial record since 1961.The anomalously lower temperature took place under the background of an Laina episode,which exerted significant impact on the climate of the Eurasian conti-nent via the general circulation.Compared with the average year,the circulation was more meridional in the mid-and higher-latitudes of Eurasia and a major trough in East Asia and a prominent high in Mongolia were stronger,steering excessive cold air from eastern Siberia and the regions to its north to advance southward.In the meantime,a southerly warm and humid airflow active over the low latitudes met with the cold air from the north over the province to cause clouds and rains,inhibiting adiabatic heating at the surface and heating effects arising from descending atmospheric motion,and thus leading to the anomalously lower temperature in May 2022.

关 键 词：气候学 异常低温 环流异常 拉尼娜事件(La Ni1a) 5月 广东省 

分 类 号：P46[天文地球—大气科学及气象学]