Scopus记录号: 2-s2.0-85044034149
论文题名: Ekman pumping mechanism driving precipitation anomalies in response to equatorial heating
作者: Hamouda M.E. ; Kucharski F.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2019
卷: 52, 期: 2019-01-02 起始页码: 697
结束页码: 711
语种: 英语
英文关键词: Ekman pumping
; Monsoon
; Rainfall
; Teleconnections
英文摘要: In this paper some basic mechanisms for rainfall teleconnections to a localized tropical sea surface temperature anomaly are re-visited using idealized AGCM aqua-planet simulations. The dynamical response is generally in good agreement with the Gill–Matsuno theory. The mechanisms analyzed are (1) the stabilization of the tropical troposphere outside the heating region, (2) the Walker circulation modification and (3) Ekman pumping induced by the low-level circulation responses. It is demonstrated that all three mechanisms, and in particular (2) and (3), contribute to the remote rainfall teleconnections. However, mechanism (3) best coincides with the overall horizontal structure of rainfall responses. It is shown by using the models boundary layer parameterization that low-level vertical velocities are indeed caused by Ekman pumping and that this induces vertical velocities in the whole tropospheric column through convective feedbacks. Also the modification of the responses due to the presence of idealized warm pools is investigated. It is shown that warm pools modify the speed of the tropical waves, consistent with Doppler shifts and are thus able to modify the Walker circulation adjustments and remote rainfall responses. The sensitivity of the responses, and in particular the importance of the Ekman pumping mechanism, to large variations in the drag coefficient is also tested, and it is shown that the Ekman pumping mechanism is robust for a wide range of values. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature. 资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/122457
Appears in Collections: 气候变化事实与影响
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作者单位: Astronomy and Meteorology Department, Faculty of Science, Cairo University, Cairo, Egypt; Earth System Physics Section, Abdus Salam International Centre for Theoretical Physics, Trieste, Italy; Center of Excellence for Climate Change Research/Department of Meteorology, King Abdulaziz University, Jeddah, Saudi Arabia
Recommended Citation:
Hamouda M.E.,Kucharski F.. Ekman pumping mechanism driving precipitation anomalies in response to equatorial heating[J]. Climate Dynamics,2019-01-01,52(2019-01-02)