气候变化领域集成服务门户(CCPortal): Ekman pumping mechanism driving precipitation anomalies in response to equatorial heating

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DOI	10.1007/s00382-018-4169-4
	Ekman pumping mechanism driving precipitation anomalies in response to equatorial heating
	Hamouda M.E.; Kucharski F.
发表日期	2019
ISSN	0930-7575
起始页码	697
结束页码	711
卷号	52 期号:2020-01-02
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.
英文关键词	Ekman pumping; Monsoon; Rainfall; Teleconnections
语种	英语
scopus关键词	boundary layer; Ekman pumping; equatorial dynamics; heating; monsoon; parameterization; precipitation (climatology); sea surface temperature; teleconnection; temperature anomaly; tropical region; troposphere; Walker circulation; warm pool
来源期刊	Climate Dynamics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/146614
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
推荐引用方式 GB/T 7714	Hamouda M.E.,Kucharski F.. Ekman pumping mechanism driving precipitation anomalies in response to equatorial heating[J],2019,52(2020-01-02).
APA	Hamouda M.E.,&Kucharski F..(2019).Ekman pumping mechanism driving precipitation anomalies in response to equatorial heating.Climate Dynamics,52(2020-01-02).
MLA	Hamouda M.E.,et al."Ekman pumping mechanism driving precipitation anomalies in response to equatorial heating".Climate Dynamics 52.2020-01-02(2019).