摘要
利用站点资料和高分辨率再分析资料,对2022年西北干旱区夏季一次持续性高温天气进行诊断分析,并对高温的贡献因子作定量估计。研究结果表明:(1)研究区内高温达2092个站次,主要分布在西北干旱区偏北区域,其中108个站最高温突破近40年历史极值,98个站高温持续日数超过10天,均属历史罕见。(2)此次高温过程影响范围广,持续时间长。高温持续期,南亚高压中心位置较同期偏北,强度较同期偏强。过程前期受中高层暖脊影响,在过渡期暖脊东移,大陆高压逐渐东伸,后期大陆高压发展强盛,并向东延伸与西伸的西太平洋副热带高压(以下简称西太副高)相互连通,影响西北区大部分区域。西北区境内水汽辐散偏强,不易形成降水,同时下沉气流异常偏强,高层空气下沉增温,有利于高温天气的发展与维持。(3)无论是过程前期还是后期,温度平流项在升温过程中贡献较小,而垂直输送项和非绝热加热项均是影响极端高温天气的关键因子,从影响因子类别角度,过程前期以动力因子贡献为主,形成稳定热穹顶后,在过程后期以热力贡献占主导地位。
Based on station data and high-resolution reanalysis data,this study conducted a diagnostic analysis of the persistent heat wave that occurred in the arid region of northwest China during the summer of 2022 and quantified the contributing factors.The results showed a total of 2092 occurrences of high temperatures,primarily concentrated in the northern part of northwest China.Furthermore,the high temperatures exceeded historical extreme values recorded in the past 40 years at 108 stations and persisted for over 10 days at 98 stations,both of which are historically rare occurrences.The studied heatwave has a wide impact and long duration.During the prolonged period of high temperatures,the South Asian high-pressure center is positioned further north than usual and exhibits stronger intensity.In the early stages of the event,it is influenced by the warm ridge in the mid to upper levels,which gradually shifts eastward during the transition period.The continental high-pressure system gradually extends eastward and connects with the western Pacific subtropical high-pressure system(referred to as the"Western Pacific Subtropical High")which extends both eastward and westward.This connection affects most of the northwestern regions.Within the northwestern region,there is strong water vapor divergence,making it difficult for precipitation to form.At the same time,there is an abnormal strengthening of the descending airflow,leading to warming in the upper atmosphere,which favors the development and maintenance of hot weather conditions.Whether it is in the early or later stages of the process,the temperature advection term contributes minimally to the warming process,while the vertical transport term and non-adiabatic heating term are key factors that influence extreme heat weather.From the perspective of influencing factors,the early stage of the process is mainly influenced by dynamic factors,while in the later stage,thermodynamic contributions dominate after the formation of a stable heat do stable heat dome.
作者
王勇
秦豪君
王澄海
程蓉
马莉
叶培龙
付正旭
周子涵
WANG Yong;QIN Haojun;WANG Chenghai;CHENG Rong;MA Li;YE Peilong;FU Zhengxu;ZHOU Zihan(Key Laboratory of Climate Resources Development and Disaster Prevention and Mitigation of Gansu,Lanzhou 730000,Gansu,China;College of Atmospheric Sciences,Lanzhou University,Lanzhou 730000,Gansu,China;Lanzhou Central Meteorological Observatory,Lanzhou 730000,Gansu,China;Lanzhou Institute of Arid Meteorological,China Meteorological Administration,Lanzhou 730000,Gansu,China)
出处
《高原气象》
CSCD
北大核心
2024年第2期450-463,共14页
Plateau Meteorology
基金
甘肃省科技重大专项计划项目(20ZD7FA005)
国家自然科学基金项目(91837205)
甘肃省重点实验室建设基金项目(20JR10RA654)
甘肃省气象局气象科研项目-重点项目(Zd2022-03)
高原与盆地暴雨旱涝灾害四川省重点实验室开放研究基金项目(SZKT202103)
干旱气象科学研究基金项目(IAM202116)。
关键词
持续性高温
成因分析
异常特征
热量贡献
persistent high temperature
cause analysis
abnormal characteristics
thermal contribution
