1961-2018年西南地区夏季干旱变化特征及其与环流异常的联系
DOI:
作者:
作者单位:

1.①南京信息工程大学 气象灾害教育部重点实验室/气候与环境变化国际合作联合实验室/气象灾害预报预警与评估协同创新中心;2.②成都流体动力创新中心

作者简介:

通讯作者:

中图分类号:

基金项目:

国家重点研发计划重点专项(2019YFC1510201);国家自然科学基金项目(41975073);江苏省高校优势学科建设工程资助项目(PAPD)


Variation characteristics of summer drought in Southwest China and its relationship with circulation anomalies during 1961 and 2018
Author:
Affiliation:

1.Key Laboratory of Meteorological Disaster,Ministry of Education/Joint International Research Laboratory of Climate and Environment Change/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters,Nanjing University of Information Science and Technology;2.China;3.Chengdu Fluid Dynamics Innovation Center

Fund Project:

The National key Research and Development Plan(2019YFC1510201); The National Natural Science Foundation of China(41975073); Project Supported by Superior Discipline Construction Project of Universities in Jiangsu Province (PAPD)

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

    利用1961-2018年中国西南地区312站降水观测资料、NCEP/NCAR再分析资料及海表温度资料,采用夏季SPI(Standardized Precipitation Index)指数作为干旱指数,研究了西南地区夏季干旱变化特征及其与环流异常的联系。结果表明:西南地区夏季总体呈变干趋势,尤其在云南、四川东南部干旱化趋势显著。当西南地区夏季显著干旱时,该地区对流层低层辐散,上层辐合,且向该地区的水汽输送偏少。造成西南地区干旱维持的原因可归结为大气波动活动异常和海温异常强迫。前者通过西风带扰动向下游的能量频散,为西南地区低层辐散、上层辐合的环流异常的形成和维持提供了必要的扰动能量积聚,后者通过热带西北太平洋异常热源对大气的强迫,使得该地区对流层低层(上层)形成异常辐合(辐散),在西南地区和热带西北太平洋形成了斜向垂直环流,使西南地区受下沉气流控制,从而形成了利于降水显著偏少和干旱发生并维持的条件。这些结果有利于深刻认识西南干旱的形成机理和为预测提供有用的线索。

    Abstract:

    Based on the observed precipitation data from 312 stations in Southwest China, NCEP/NCAR reanalysis data and sea surface temperature data from 1961 to 2018, the summer SPI index was used to study the variation characteristics of summer drought in Southwest China and its relationship with circulation anomalies. Results indicate that Southwest China has a drying trend in summer, especially in Yunnan and southeast Sichuan. For typical dry summers, Southwest China is characterized by low-level divergence and high-level convergence, and the water vapor transported to the area is less. The reason for the maintenance of drought in Southwest China can be attributed to the abnormal atmospheric wave and the abnormal forcing of sea temperature. The former disperses energy downstream through the disturbance of the westerly zone, which provides the necessary disturbance energy accumulation for the formation and maintenance of low-level divergence and high-level convergence in Southwest China; the latter forced the atmosphere through anomalous heat sources in the tropical Northwest Pacific, causing the lower (upper) troposphere in the region to form an abnormal convergence (divergence), and an oblique vertical circulation to be formed in Southwest China and the tropical Northwest Pacific, which makes Southwest China controlled by the sinking airflow, thus forming conditions conducive to the occurrence and maintenance of significantly less precipitation and drought. These results are conducive to a deep understanding of the formation mechanism of drought in Southwest China and provide useful clues for prediction.

    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:2021-01-14
  • 最后修改日期:2021-03-24
  • 录用日期:2021-03-25
  • 在线发布日期:
  • 出版日期:

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 ® 2021 版权所有  技术支持:北京勤云科技发展有限公司