首页    期刊浏览 2025年06月10日 星期二
登录注册

文章基本信息

  • 标题:Teleconnections associated with the intensification of the Australian monsoon during El Niño Modoki events
  • 本地全文:下载
  • 作者:A S Taschetto ; R J Haarsma ; A Sen Gupta
  • 期刊名称:IOP Conference Series: Earth and Environmental Science
  • 印刷版ISSN:1755-1307
  • 电子版ISSN:1755-1315
  • 出版年度:2010
  • 卷号:11
  • DOI:10.1088/1755-1315/11/1/012031
  • 出版社:IOP Publishing
  • 摘要:

    In this study we investigate the teleconnection between the central-western Pacific sea surface temperature (SST) warming, characteristic of El Niño Modoki events, and Australian rainfall using observations and atmospheric general circulation model experiments. During Modoki events, wet conditions are generally observed over northwestern Australia at the peak of the monsoon season (i.e. January and February) while dry conditions occur in the shoulder-months (i.e. December and March). This results in a shorter but more intense monsoon season over northwestern Australia relative to the climatology. We show that, apart from the well-known displacement of the Walker circulation, the anomalous warming in the central-western equatorial Pacific also induces a westward-propagating disturbance associated with a Gill-type mechanism. This in turn generates an anomalous cyclonic circulation over northwestern Australia that reinforces the climatological mean conditions during the peak of the monsoon season. The anomalous circulation leads to convergence of moisture and increased precipitation over northern Australia. This response, however, only occurs persistently during austral summer when the South Pacific Convergence Zone is climatologically strengthened, phase-locking the Gill-type response to the seasonal cycle. The interaction between the interannual SST variability during El Niño Modoki events and the evolution of the seasonal cycle intensifies deep convection in the central-west Pacific, driving a Gill-type response to diabatic heating. The intensified monsoonal rainfall occurs strongly in February due to the climatological wind conditions that are normally cyclonic over northwestern Australia.

国家哲学社会科学文献中心版权所有