非典型大西洋尼诺对中国东部前、后汛期降水的影响
作者:
作者单位:

作者简介:

通讯作者:

中图分类号:

基金项目:

国家自然科学基金资助项目(42088101);国家重点研发计划项目(2022YFF0801702)


Impacts of non-canonical Atlantic Niño on eastern China precipitation in the early and late rainy seasons
Author:
Affiliation:

Fund Project:

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

    采用1979—2020年共42 a的降水观测和再分析资料,使用多变量EOF、傅立叶滤波、线性回归、T-N波通量等方法,研究了非典型大西洋尼诺(Non-Canonical Atlantic Niño,NCA)对中国东部夏季前、后汛期降水的影响及物理机制。结果显示,NCA在前汛期引起中国南方降水增加,但在后汛期导致华南沿海地区降水减少而北方降水增加。这是由于在前汛期,NCA的暖海温异常位于热带北大西洋,可通过“风-蒸发-海表温度”正反馈引起拉尼娜,进而激发西北太平洋异常反气旋,其西北侧的异常西南气流有助于将暖湿水汽输送至我国南方,导致前汛期南方降水增加。在后汛期,NCA的暖海温异常南移至赤道大西洋,通过调节沃克环流增强拉尼娜,使得西北太平洋异常反气旋进一步增强并覆盖华南地区,导致华南降水减少而北方降水增加。此外,与NCA相关的东传罗斯贝波列在前/后汛期位于副热带/中高纬地区,其在我国东部引起的环流异常也有助于NCA在前/后汛期影响我国南/北方降水。

    Abstract:

    Exploring the potential predictability of seasonal precipitation in Eastern China beyond the preceding winter El Nino-Southern Oscillation (ENSO) has long been a significant challenge.This study investigates the influences of the non-canonical Atlantic Niño (NCA) on precipitation patterns in Eastern China during the early and late rainy seasons using observational and reanalysis data from 1979 to 2020.Results indicate that the NCA leads to increased precipitation in southern China during the early rainy season,while it decreases precipitation along the southern coast but increases precipitation in northern China during the late rainy season.This is because,in the early rainy season,warm sea surface temperature (SST) anomalies associated with the NCA in the North Tropical Atlantic trigger La Niña through the “wind-evaporation-SST” feedback,inducing an anomalous anticyclone over the western North Pacific.The southwesterly flow along the northwest flank of this anomalous anticyclone transports warm and moist air into southern China,resulting in increased precipitation.Conversely,during the late rainy season,NCA-related warm SST anomalies migrate southward to the equatorial Atlantic,modifying the Walker circulation,reinforcing La Niña,and intensifying the anomalous anticyclone over the western North Pacific.This enhanced anticyclone covers the southern coastal region of China,reducing precipitation there,while further northward moisture transport along the enhanced anticyclone increases precipitation in northern China.Additionally,NCA influences Eastern China’s precipitation by stimulating different mid-high-latitude Rossby waves in the early and late rainy seasons.In the early rainy season,the Rossby wave is primarily triggered by anomalous warm SST in the North Tropical Atlantic,propagating from northern Africa to the Qinghai-Tibet Plateau and eventually reaching the Yangtze River basin.Although the SST anomalies in the Tropical North Atlantic weaken during the late rainy seasons,the North Atlantic Oscillation can still strengthen through local air-sea coupling,thereby developing SST in the North Atlantic.The Rossby wave,induced by an anomalous SST in the North Atlantic,across the Eastern European Plain,the Siberian Plain,and Lake Baikal,propagates southeastward to northern China,forming an anticyclonic anomaly in the upper troposphere and facilitating precipitation in northern China.This study reveals distinct seasonal variations in NCA-related precipitation anomalies in Eastern China,highlighting the complexity of large-scale circulation responses to the NCA.It provides a vital scientific basis for improving precipitation forecasting and early warning systems in China.Further investigation is needed to determine the extent to which numerical models can simulate NCA and its teleconnections.

    参考文献
    相似文献
    引证文献
引用本文

杨萌洲,袁潮霞,2024.非典型大西洋尼诺对中国东部前、后汛期降水的影响[J].大气科学学报,47(2):260-272. YANG Mengzhou, YUAN Chaoxia,2024. Impacts of non-canonical Atlantic Niño on eastern China precipitation in the early and late rainy seasons[J]. Trans Atmos Sci,47(2):260-272. DOI:10.13878/j. cnki. dqkxxb.20240109016

复制
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:2024-01-09
  • 最后修改日期:2024-02-08
  • 录用日期:
  • 在线发布日期: 2024-05-22
  • 出版日期: 2024-03-28

地址:江苏南京宁六路219号南京信息工程大学    邮编:210044

联系电话:025-58731158    E-mail:xbbjb@nuist.edu.cn    QQ交流群号:344646895

大气科学学报 ® 2024 版权所有  技术支持:北京勤云科技发展有限公司