双月刊

ISSN 1006-9895

CN 11-1768/O4

春季北大西洋三极型海温异常模态与中国东部极端低温事件频次年际变化关系的年代际增强
作者:
作者单位:

1.成都信息工程大学大气科学学院;2.中国科学院大气物理研究所

作者简介:

通讯作者:

基金项目:


Interdecadal enhancement of the interannual relationship between spring North Atlantic tripolar SST mode and extreme cold event frequency in eastern China
Author:
Affiliation:

Institute of Atmospheric Physics, Chinese Academy of Sciences

Fund Project:

  • 摘要
  • |
  • 图/表
  • |
  • 访问统计
  • |
  • 参考文献
  • |
  • 相似文献
  • |
  • 引证文献
  • |
  • 资源附件
    摘要:

    本文研究了春季北大西洋海温异常与中国东部极端低温事件频次年际变化之间的关系。结果表明,北大西洋三极型海温异常模态(NATSST)在20世纪80年代末后可以显著影响中国东部极端低温事件频次第一主导模态的变化,但在80年代末之前却不能。进一步的机制分析表明,这两者关系之所以发生年代际变化,可能与NATSST激发的遥相关波列在20世纪80年代末前后期不同有关。在1960-1987年,NATSST激发的遥相关波列从北大西洋向中亚南部地区传播,路径偏南,对东亚地区大气环流的影响较弱,从而不能显著影响中国东部地区极端低温事件的变化。但在1992-2019年,NATSST能够激发南、北两支遥相关波列到达东亚。其中,北支波列与北大西洋涛动(NAO)有关,该波列从北大西洋出发沿欧亚中高纬向东传播,可以在蒙古地区造成异常气旋/反气旋性环流;南支波列从北大西洋出发沿欧亚中低纬向东传播,可以在中国中南部造成异常气旋/反气旋性环流。上述气旋/反气旋性环流有利/不利于中高纬冷空气南下,同时改变中国东部地区地表热通量,从而造成有利/不利于极端低温事件发生的气候背景条件,使得中国东部地区极端低温事件频次增加/减少。通过上述物理过程,NATSST在20世纪80年代末之后可以显著影响中国东部春季极端低温事件频次的年际变化,而在80年代末之前则不能。

    Abstract:

    The relationship between spring sea surface temperature in the North Atlantic and extreme cold event (ECE) frequency in eastern China at interannual timescale is investigated in this paper. The results show that the North Atlantic tripolar SST mode (NATSST) can significantly affect the first leading mode of ECE frequency in eastern China after the late 1980s, but not before. Further mechanistic analysis suggests that such an interdecadal change in the relationship between the two could be related to the difference in the NATSST-excited wave trains before and after the late 1980s. In 1960-1987, the NATSST-related wave train propagates from the North Atlantic to southern Central Asia, which is located more southward and consequently has a weak influence on atmospheric circulations and ECE in eastern China. However, in 1992-2019, NATSST can excite two wave trains. The northern one is associated with the North Atlantic Oscillation (NAO), which propagates eastward from the North Atlantic to mid-high latitudes of Eurasia, resulting in anomalous cyclonic/anticyclonic circulation in the Mongolian region. The southern one propagates eastward from the North Atlantic to mid-low latitudes of Eurasia, leading to anomalous cyclonic/anticyclonic circulation in southern-central China. These cyclonic/anticyclonic circulations are favorable/unfavorable to the southward movement of cold air from middle and high latitudes, and also change the surface heat flux in eastern China, consequently providing favorable/unfavorable climate background conditions for the occurrence of ECE. Through these physical processes, NATSST can significantly influence the interannual variability of the frequency of spring ECE in eastern China after the late 1980s, but not before.

    参考文献
    相似文献
    引证文献
引用本文
分享
文章指标
  • 点击次数:
  • 下载次数:
  • HTML阅读次数:
  • 引用次数:
历史
  • 收稿日期:2021-09-10
  • 最后修改日期:2022-01-06
  • 录用日期:2022-01-24
  • 在线发布日期: 2022-02-24
  • 出版日期: