金沙江下游高温天气的环流分型和诊断

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中文摘要：金沙江流域作为我国重要的生态屏障和清洁能源输出地,其下游干热河谷地段是高温频发地区,针对该区域开展高温天气环流特征和诊断对提高高温灾害预报水平和提高该区域能源调度效率具有重要意义.利用1981-2020年逐日最高气温资料和欧洲中期天气预报中心(the European Centre for Medium-Range Weather Forecasts,ECMWF)第五代大气再分析数据集ERA5(Reanalysis v5),通过K-means聚类分析法对金沙江下游高温天气环流形势进行分型,并对各类高温天气的动力和热力因子进行诊断,提炼出各型高温的物理量阈值.结果表明:金沙江下游高温天气的环流背景可分为暖脊型、副热带高压-青藏高压型和青藏高压型3种类型.高温期间中高层均有≥0.25 Pa·s-1的下沉气流,天空晴朗无云,晴空辐射强,且近地面受到≤800 hPa强度的热低压直接加热作用.热力诊断发现金沙江下游高温主要由非绝热加热引起,温度平流对局地升温的贡献为负,垂直绝热变化贡献接近于0,但下沉气流有利于地面接收更多太阳辐射,使近地层非绝热加热增加,从而导致金沙江下游出现高温天气.

外文标题：Synoptic circulation patterns clustering analysis and physical diagnosis of high temperature weather in the lower reaches of the Jinsha River

外文摘要：The Jinsha River basin is an important ecological barrier and clean energy export area in China,while its downstream is a dry and hot valley section with frequent high temperature weathers.Conducting high temperature weather circulation characteristics and diagnostic analysis is of great significance for improving the prediction level of high temperature disaster weather and the efficiency of energy dispatch in this region.Based on the daily maximum temperature data from meteorological stations and the fifth generation at-mospheric reanalysis dataset ERA5(Reanalysis v5)from the European Center for Medium-Range Weather Forecasts(ECMWF)from 1981 to 2020,the atmospheric circulation of high temperature weather in the lower reaches of the Jinsha River were classified by using K-means cluster analysis method,and the dynamic and thermal factors of high temperature weather were diagnosed and the physical quantities thresholds that characterize the high temperature weather were established.The results show that the atmospheric circulation patterns of high temperature weather in research area could be divided into three types,including warm-ridge type,subtropical high-Tibetan high type and Tibetan high type.During the high temperature period,there is a strong downdraft with strength above 0.25 Pa·s-1 in the middle and upper layers.The sky is clear and cloudless with strong radiation.The near ground is directly heated by thermal low pressure with strength lower than 800 hPa.According to the diagnosis,the high temperature in the lower reaches of the Jinsha River is mainly caused by non-adiabatic heating.The contribution of temperature advection to local temperature rise is negative and the contri-bution of vertical adiabatic is close to zero.However,the downdraft is favorable for the surface to receive more solar radiation,which in-creases the non-adiabatic heating of the surface,resulting in high temperature weather in the lower reaches of the Jinsha River.

外文关键词：

the Jinsha Riverhigh temperaturecluster analysiscirculation typingdiagnosis of dynamic and thermal mechanisms

作者：

黄瑶、袁梦、郭洁、宋雯雯、刘新超

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作者单位：

高原与盆地暴雨旱涝灾害四川省重点实验室,四川成都 610072

四川省气象服务中心,四川成都 610072

四川省农村经济综合信息中心,四川成都 610072

中国气象局大气探测重点开放实验室,四川成都 610225

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关键词：

金沙江高温天气聚类分析环流分型动力和热力诊断

基金：

高原与盆地暴雨旱涝灾害四川省重点实验室科技发展基金研究型业务面上专项高原与盆地暴雨旱涝灾害四川省重点实验室科技发展基金研究型业务面上专项中国气象局大气探测重点开放实验室开放课题四川省气象服务中心能源气象技术研究与应用服务创新团队基金

项目编号：

SCQXKJYJXMS202217SCQXKJYJXMS2023152023KLAS06MCXTD 202303

出版年：

2024

DOI：

10.11755/j.issn.1006-7639(2024)-02-0217

干旱气象

中国气象局兰州干旱气象研究所中国气象学会干旱气象学委员会

干旱气象

CSTPCD

影响因子：1.9

ISSN：1006-7639

年,卷(期)：2024.42(2)

参考文献量24