一次云南干季极端暴雨成因分析  

Analysis of cause for an extreme torrential rain process in the dry season over Yunnan Province

作　　者：米瑞芝 牛法宝[1,2] 赵建萍 王志云 米智伟[4] 鲁亚斌 孙绩华[1,2] MI Rui-zhi;NIU Fa-bao;ZHAO Jian-ping;WANG Zhi-yun;MI Zhi-wei;LU Ya-bin;SUN Ji-hua(Yunnan Meteorological Observatory,Kunming 650034,Yunnan,China;Research Center for Disastrous Weather over Hengduan Mountains&Low-Latitude Plateau,CMA,Kunming 650034,Yunnan,China;Cangyuan Washan Airport Meteorological Observatory of Yunnan Airport Group,Cangyuan 677400,Yunnan,China;Weinan Meteorological Bureau,Shaanxi Province,Weinan 714000,Shaanxi,China)

机构地区：[1]云南省气象台,云南昆明650034 [2]中国气象局横断山区(低纬高原)灾害性天气研究中心,云南昆明650034 [3]云南机场集团沧源佤山机场气象台,云南沧源677400 [4]陕西省渭南市气象局,陕西渭南714000

出　　处：《云南大学学报（自然科学版）》2023年第4期886-895,共10页Journal of Yunnan University(Natural Sciences Edition)

基　　金：第二次青藏高原综合科学考察研究项目(2019QZKK0105);国家自然科学基金(41765003);云南省气象局自筹科研项目(YZ202102).

摘　　要：利用NCEP再分析资料、常规及非常规气象观测资料,综合分析2015年1月9日云南干季极端暴雨天气过程.结果表明:深厚的南支槽、低空切变线及地面冷锋共同作用导致此次过程;强位相热带季节内振荡(Madden-Julian Oscillation,MJO)处于“湿窗口”期,对水汽输送及对流发展有指示作用;南支槽前西南低空急流输送充沛水汽,暴雨落区与水汽强辐合区基本一致;高低空急流耦合,云南处于高空急流次级环流上升支,受锋面抬升,锋区次级环流上升支与高空急流次级环流上升支叠加,形成极强的上升运动;西南低空急流输送不稳定能量,滇西南暴雨区以强对流天气为主,滇中暴雨区以稳定性降水为主;结合稳定度参数的综合分析,有助于判断云南干季强对流天气落区.The extreme dry season torrential rain process that occurred on January 9,2015 over Yunnan Province was explored based on the NCEP reanalysis data,the conventional and unconventional observation data.The results showed that this process was caused by a deep Southern Branch Trough over the middle of the Bay of Bengal,the shear line on 700 hPa and the cold front on ground.The strong MJO was during the“wet window”period,which was also an indicator for the water vapor transport and the development of convection.During that process,the southwest low-level jet in front of the Southern Branch Trough provided abundant water vapor.The rainstorm area was basically consistent with strong vapor convergence area.Under the coupling of the high-level and low-level jets,the ascending branch of secondary circulation forced by the high-level jet affected Yunnan Province.The uplift of the cold front,and the ascending branches of secondary circulations forced by the cold front and the jet,led to the enhancement of updraft.The unstable energy transported by the southwest low-level jet led to such convective weather:the rainstorm area in Southwest Yunnan was dominated by strong convective weather,while the rainstorm area in central Yunnan was dominated by stable precipitation.Obviously,the comprehensive analysis by taking atmospheric stability into account was helpful to judge the location of severe convective weather over Yunnan Province in the dry season.

关 键 词：干季暴雨 热带季节内振荡(MJO) 南支槽 高低空急流 干季强对流 云南 

分 类 号：P458[天文地球—大气科学及气象学]