干旱气象 ›› 2023, Vol. 41 ›› Issue (6): 860-872.

• 厄尔尼诺与干旱 • 上一篇    下一篇

厄尔尼诺/南方涛动事件对云南秋季气象干旱的不同影响分析

  

  1. 1. 云南省气候中心,云南 昆明 650034
    2. 云南省气象台,云南 昆明 650034
    3. 云南省大湄公河次区域气象灾害与气候资源重点实验室,云南 昆明 650034
  • 收稿日期:2023-10-20 修回日期:2023-11-07 出版日期:2023-12-31 发布日期:2024-01-03
  • 通讯作者: 金燕(1978—),女,云南楚雄人,高级工程师,主要气候变化及生态气象研究。E-mail:apple_jjyy25@163.com。
  • 作者简介:马思源(1990—),女,云南曲靖人,工程师,主要从事气候变化及气象灾害研究。E-mail:masiyuan_c@163.com。
  • 基金资助:
    中国气象局气象能力提升联合研究专项22NLTSZ005)、云南省基础研究专项重点基金项目202201AS070069)、云南省重点研发计划-社会发展专项202203AC100005202203AC100006)及云南省自然科学基金项目(202302AN360006

Different impacts of El Niño/Southern Oscillation events on autumn meteorological drought in Yunnan Province#br#

  1. 1. Yunnan Climate Center, Kunming 650034, China;
    2. Yunnan Meteorological Observatory, Kunming 650034, China;
    3. Yunnan Key Laboratory of Meteorological Disasters and Climate Resources in the Greater Mekong Subregion,Kunming 650034, China
  • Received:2023-10-20 Revised:2023-11-07 Online:2023-12-31 Published:2024-01-03

摘要: 云南是我国干旱灾害高发区,为增进厄尔尼诺/南方涛动(El Niño/Southern Oscillation,ENSO)

对云南干旱影响的认知,提升云南秋季气象干旱预测能力,采用1979—2022年云南125个气象站逐日
降水资料、英国国家气象局哈德莱中心(Hadley Center)逐月海表温度(Sea Surface Temperature,SST)资
料及欧洲中期天气预报中心(European Centre for Medium-Range Weather Forecasts,ECMWF)第五代再
分析资料(the Fifth Generation of European Reanalysis,ERA5),揭示两类 ENSO事件对导致云南秋季气
象干旱的降水异常影响及相应的物理过程。结果表明:(1)中部(Central Pacific,CP)型 El Niño 或 La
Niña事件同期,云南秋季降水以偏少为主;东部(Eastern Pacific,EP)型El Niño或La Niña事件同期,云
南秋季降水则以偏多为主,且 EP 型 El Niño 是云南秋季降水偏多的强信号。(2)EP 型 El Niño 年和 La
Niña年,500 hPa位势高度场在欧亚大陆中低纬呈负距平,西太平洋副热带高压偏西,西南暖湿气流与
冷空气在云南交汇,中低层以上升运动为主,有利于降水产生。CP型El Niño年和La Niña年,500 hPa
位势高度在云南附近为正距平,加之向外长波辐射正异常,对流活动较弱,不利于云南地区的降水。
(3)ENSO事件SST异常激发的赤道西北太平洋气旋(反气旋)环流的位置东西偏移是导致云南秋季降
水异常的重要因素。

关键词: 云南, 秋季, 气象干旱, 两类厄尔尼诺/南方涛动事件, 西北太平洋气旋

Abstract: Yunnan Province is frequently affected by drought catastrophes, in order to enhance the understanding of the influence of El

Niño/Southern Oscillation (ENSO) on drought and to improve the prediction ability of meteorological drought in autumn in Yunnan Province, the paper revealed the influence of two types of ENSO events on precipitation anomalies resulting in autumn meteorological drought in Yunnan and the associated physical processes based on monthly average sea surface temperature (SST) data from the Hadley Center, the fifth generation of European reanalysis data (ERA5) from the European Centre for Medium-Range Weather Forecasts (ECMWF), and daily precipitation data from 125 meteorological stations in Yunnan Province from 1979 to 2022. The results are as follows: (1) During the period of Central Pacific (CP) type El Niño or La Niña events, the autumn precipitation in Yunnan is mainly less.Conversely, during the period of Eastern Pacific (EP) type El Niño or La Niña events, the autumn precipitation in Yunnan is mainly more. Furthermore, the EP type El Niño event is a strong signal of more autumn precipitation in Yunnan. (2) In the years of the EP type El Niño and La Niña, the 500 hPa geopotential-height field presents a negative anomaly over the middle and low latitudes of Eurasia, the Western Pacific subtropical high is westward, the warm and humid air from the southwest meets cold air in Yunnan, and the rising
movement is mainly in the middle and low levels, which is conducive to precipitation generation in Yunnan. In the years of the CP type El Niño and La Niña, the 500 hPa geopotential height field in Yunnan is positive anomaly. In addition, there is the positive anomaly of outgoing longwave radiation (OLR), and the convective activity is weak, which is not conducive to the precipitation in Yunnan. (3)When ENSO event occurs, The east-west shift of the position of the equatorial northwest Pacific cyclonic (anticyclonic) circulation excited by the SST anomaly of ENSO event is an important factor leading to the autumn precipitation anomaly in Yunnan.

Key words: Yunnan, autumn, meteorological drought, two types of El Ni?o/Southern Oscillation, Northwest Pacific cyclone

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