2023年麦收期河南省连阴雨的气候特征和可能成因  

Climatic Characteristics and Possible Causes of Continuous Rainy Weather in Henan Province during the Wheat Harvest Season in 2023

作　　者：竹磊磊 史恒斌[1,2] 王建新[3] 苏晓乐[1,2] 李凤秀 Zhu Leilei;Shi Hengbin;Wang Jianxin;Su Xiaole;Li Fengxiu(Henan Key Laboratory of Agrometeorological Support and Applied Technique,CMA,Zhengzhou 450003,China;Henan Climate Centre,Zhengzhou 450003,China;Anyang Meteorological Office,Anyang 455000,China)

机构地区：[1]中国气象局·河南省农业气象保障与应用技术重点开放实验室,郑州450003 [2]河南省气候中心,郑州450003 [3]安阳市气象局,河南安阳455000

出　　处：《气象与环境科学》2024年第1期45-56,共12页Meteorological and Environmental Sciences

基　　金：中国气象局复盘总结专项(FPZJ2024-080);中国气象局气候变化专项(CCSF201911);河南省气象局气象科学技术研究重点项目(KZ201705、KM202307)。

摘　　要：2023年麦收期河南省出现了罕见的连阴雨天气,降水和阴雨日数异常偏多,分别为自1961年以来的历史第五位和第二位。分析连阴雨的可能气候成因,主要结论如下:(1)造成连阴雨的环流形势为欧亚中高纬度西高东低,乌拉尔山高压脊持续发展并出现阶段性阻塞,东北冷涡活跃,冷空气能持续南下,西太平洋副热带高压(以下简称副高)偏北、偏强且异常偏西,来自副高西北侧边缘的暖湿气流和冷空气在河南省交汇。(2)副高偏强、偏北、偏西是由偏强、偏北、偏大、偏东的南亚高压和偏强、偏北的东亚副热带西风急流(以下简称西风急流)的引导所致,而东南亚对流层中高层的暖中心偏大、偏北和偏东且呈东西向带状分布,使南亚高压形成了上述的特征。暖中心和东北冷涡的共同作用,使东亚中高层的气温梯度增大,进而加强了西风急流。(3)2023年前期的La Ni1a事件有利于麦收期副高偏北,但不利于副高偏强和明显偏西。麦收期由于台风扰动由泰国湾至菲律宾群岛以东的热带西太平洋对流活跃释放的凝结潜热较多,以及麦收期前期的春季和麦收期伊朗高原至青藏高原的地面感热和潜热较强,使暖中心形成了上述的特征,进而决定了南亚高压和副高的特征。(4)2023年麦收期北大西洋海温偏高,以及北大西洋三极子为负位相,导致了乌拉尔山高压脊持续发展并出现阶段性阻塞,麦收期前期的春季和麦收期伏尔加河至贝加尔湖西北侧地面感热和潜热偏强,而下游贝加尔湖东南侧至鄂霍次克海地面感热和潜热偏弱一定程度上导致上述两区域分别出现了大范围的位势高度正距平和负距平。During the wheat harvest season in 2023,Henan Province suffered rare and persistent rainy weather,in which the amount of precipitation and the number of rainy or sunless days were pronounced high,ranking the fifth and the second since 1961,respectively.This paper analyzed the climatological causes of this event and the main conclusions were as follows:(1)Geopotential height anomaly at 500 hPa was positive in the west,while was negative in the east over Eurasian mid-high latitude during the wheat harvest season,the Ural Mountain ridge developed sustainably with staged blocking,and the Northeast China cold vortex(NECV)was very active,making cold air keep moving down to the south.The western Pacific subtropical high(WPSH)was much stronger than normal,located more northwards and westwards,thus the warm and humid air from the northwest edge of the WPSH and cold air could converge in Henan Province.The above circulation systems were conducive to the continuous rain.(2)The pattern of the WPSH was mainly affected by the guidance of the South Asian high(SAH)and the East Asian subtropical westerly jet.The Southeast Asian warm center at mid-upper level was larger,more eastward and northward than normal,having an east-west zonal distribution,which resulted in the strong,large,northward and eastward pattern of the SAH.The combination of the warm center and the NECV increased the temperature gradient at mid-upper level of East Asia,thus intensified the westerly jet.(3)The La Ni a event in early 2023 was favorable for northward shift of the WPSH during the wheat harvest season,but wasn’t conducive to the strong and distinct westward pattern of the WPSH.Due to the influence of Typhoon Mawa,more condensation latent heat was released by active convection from the Gulf of Thailand to tropical western Pacific east of the Philippine Islands during the wheat harvest season,meanwhile the surface sensible heat and the latent heat from the Iranian Plateau to the Tibetan Plateau were much stronger than normal in the spring before the wh

关 键 词：麦收期 连阴雨 西太平洋副热带高压 乌拉尔山阻塞高压 东北冷涡 南亚高压 西风急流 

分 类 号：S161[农业科学—农业气象学]