地理学报 ›› 2022, Vol. 77 ›› Issue (5): 1120-1137.doi: 10.11821/dlxb202205006

• 气候与环境变化 • 上一篇    下一篇

亚洲夏季风北部边缘带变化及中高纬度行星波对其影响

谭政华1,2,3(), 巩远发2()   

  1. 1.中国气象局沈阳大气环境研究所,沈阳 110166
    2.成都信息工程大学大气科学学院,成都 610225
    3.辽宁省气象台,沈阳 110166
  • 收稿日期:2021-02-03 修回日期:2022-04-11 出版日期:2022-05-25 发布日期:2022-07-25
  • 通讯作者: 巩远发(1963-), 男, 博士, 教授, 主要从事短期气候异常变化的诊断和模拟研究。E-mail: gyfa@cuit.edu.cn
  • 作者简介:谭政华(1991-), 男, 辽宁朝阳人, 硕士, 工程师, 主要从事天气动力学和短期气候预测研究。E-mail: ln-tanzhenghua@outlook.com
  • 基金资助:
    国家自然科学基金项目(41775079);国家自然科学基金项目(U20A2097);中国气象局沈阳大气环境研究所和东北冷涡研究重点开放实验室联合开放基金项目(2020SYIAE10)

Characteristics of the northern marginal zone of the Asian summer monsoon and the influence of planetary waves in middle-high latitudes on its variation

TAN Zhenghua1,2,3(), GONG Yuanfa2()   

  1. 1. Institute of Atmosphere Environment, China Meteorological Administration, Shenyang 110166, China
    2. School of Atmosphere Science, Chengdu University of Information Technology, Chengdu 610225, China
    3. Liaoning Meteorological Observatory, Shenyang 110166, China
  • Received:2021-02-03 Revised:2022-04-11 Published:2022-05-25 Online:2022-07-25
  • Supported by:
    National Natural Science Foundation of China(41775079);National Natural Science Foundation of China(U20A2097);Open Foundation Project of the Institute of Atmospheric Environment, China Meteorological Administration(2020SYIAE10)

摘要:

本文使用1961—2016年NCEP1再分析资料和GPCC全球降水分析资料,确定了亚洲夏季风北部边缘带的空间范围,分析了季风边缘带的南北边界位置、降水、面积的相互关系和年代/际变化特征,讨论了造成季风边缘带夏季降水异常的影响因子。主要结论如下:亚洲夏季风北部边缘带平均位置位于青藏高原中部经黄土高原和中国东北地区向亚洲东岸延伸的带状区域上,根据下垫面性质、区域生态环境和气候特征,将季风北边缘带划分为青藏高原区(85°E~105°E)、黄土高原区(105°E~115°E)和中国东北区(115°E~135°E)3段,季风边缘带降水的年际变化与其南边界位置有显著的正相关,青藏高原季风边缘带面积变化与其南界位置显著负相关,黄土高原季风边缘带和东北季风边缘带面积与北边界位置显著正相关,且3段季风边缘带的位置、面积、降水均有明显的年际、年代际变化特征。季风边缘带夏季降水偏少与欧亚中高纬对流层上层自西向东传播的欧亚(EU)遥相关波列密切相关,季风边缘带夏季降水偏少时期,亚洲低纬度地区对流活动偏弱、非洲东岸近赤道地区200 hPa异常辐合可能造成索马里急流和亚洲夏季风强度整体偏弱,200 hPa亚洲急流强度弱且位置偏北,500 hPa中国北方受西风带异常高压控制,东亚夏季风降水主要集中在中国南方地区,季风边缘带夏季降水异常偏少。季风边缘带夏季降水偏多与欧亚中高纬对流层上层沿亚洲急流向东传播的丝绸之路(SRP)波列密切相关,200 hPa、500 hPa环流形势与季风边缘带夏季降水偏少时期基本相反,东亚夏季风降水空间分布呈北多南少特征,季风边缘带夏季降水异常偏多。

关键词: 亚洲季风, 北部边缘带, 变化特征, 影响因子

Abstract:

In this study, the NCEP1 (National Centers for Environmental Prediction) daily reanalysis data and GPCC (Global Precipitation Climatology Centre) precipitation reanalysis data from 1961 to 2016 are used to define the spatial range of the northern marginal zone of Asian summer monsoon (ASM). Then, the inter-annual and inter-decadal variations characteristics of precipitation, location and area of the northern marginal zone are analyzed, and the interactions among them are detailedly investigated. Moreover, the physical mechanisms of the summer precipitation anomalies in the ASM marginal zone are explored. The results show that the average position of the ASM northern marginal zone is located in the strip domain which initiates from the central part of the Tibetan Plateau, crosses the Loess Plateau and Northeast China and finally extends to the east coast of Asia. According to the types of underlying surface, regional ecological environment and climate characteristics, the ASM northern marginal zone is divided into three areas: Tibetan Plateau (85°E~105°E), Loess Plateau (105°E~115°E) and Northeast China (115°E~135°E). There is a notable positive correlation between the inter-annual variation of the precipitation in the ASM marginal zone and the location of its southern boundary. In the Tibetan Plateau, there is significant negative correlation between the area of marginal zone and the location of its southern boundary. For the Loess Plateau and Northeast China, there is notable positive correlation between the area and the location of northern boundary of the ASM marginal zone. Moreover, the location, area and precipitation of the three ASM marginal areas have significant inter-annual and inter-decadal variations. The abnormally less precipitation in the ASM marginal zone is related to the wave train of Eurasia teleconnection pattern over middle-high latitudes. During the period with less precipitation in the ASM marginal zone, the convective activity is weak at low-latitude areas. The anomalous convergence at 200 hPa over the equatorial region on the eastern shore of Africa may lead to the weakening of the ASM and the Somali jet. At 200 hPa, the Asian jet stream is also weaker and more northward. At 500 hPa, under the control of anomalous high pressure over North China, the precipitation caused by the ASM mainly concentrates in South China, and the precipitation in the ASM marginal zone in summer is abnormally less. The synoptic situation of 200 hPa and 500 hPa is opposite from that of ASM marginal zone with more precipitation. The abnormally more precipitation is related to the wave train of the Silk Road pattern in middle-high latitudes over Eurasia. The summer monsoon precipitation in East Asia is characterized as "more in the north and less in the south", and the summer precipitation in the ASM marginal zone is more than the normal level.

Key words: Asian monsoon, monsoon marginal zone, inter-decadal variation, influencing factor