DOI: 10.1007/s00382-017-3956-7
Scopus记录号: 2-s2.0-85031417669
论文题名: Intrinsic precursors and timescale of the tropical Indian Ocean Dipole: insights from partially decoupled numerical experiment
作者: Crétat J. ; Terray P. ; Masson S. ; Sooraj K.P.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2018
卷: 51, 期: 4 起始页码: 1311
结束页码: 1332
语种: 英语
英文关键词: Biennial variability
; Coupled climate model
; Indian Ocean Dipole
; MJO
; Ocean dynamics
; Tropical–extratropical interactions
Scopus关键词: annual variation
; anticyclone
; climate modeling
; Indian Ocean Dipole
; Madden-Julian oscillation
; numerical model
; oceanic circulation
; sea surface temperature
; timescale
; Indian Ocean
; Indian Ocean (Tropical)
; Pacific Ocean
; Pacific Ocean (Tropical)
英文摘要: The intrinsic precursors and timescale of the tropical Indian Ocean Dipole (IOD) are examined with the help of a partially coupled global experiment with decoupled SST over the tropical Pacific. The IOD does exist in the absence of sea surface temperature interannual variability in the tropical Pacific in our modeling framework, but has weaker amplitude and damped Bjerknes feedback. However, IOD variability is much more biennial in the absence than presence of El Niño Southern Oscillation, especially in the eastern equatorial Indian Ocean (IO). Such biennial rhythm results mainly from two mechanisms internal to the IO. The tropical ocean dynamics play a key role in the biennial anomalies during boreal winter with a sudden reversal of thermocline anomalies in the eastern equatorial IO forced by intraseasonal disturbances reminiscent of the Madden–Julian Oscillation (MJO). However, this preconditioning is not sufficient for triggering IOD events in the next boreal spring per se. The main trigger for pure IODs relates to tropical–extratropical interactions within the IO. Convection and diabating heating associated with negative IODs promote a Gill-type tropical response, excite mid-latitude wave-trains and subtropical blocking in the Southern Hemisphere that trigger positive subtropical IOD events during boreal winter. The latter promotes cold SST and anticyclonic circulation anomalies over the southeast IO that persist and migrate northeastward, triggering positive IOD events during the next boreal spring. Accounting for the complementary influence of tropical ocean dynamics coupled to MJO and tropical-extratropical ocean–atmosphere interactions may thus help improving IOD predictability. © 2017, Springer-Verlag GmbH Germany. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/109200
Appears in Collections: 影响、适应和脆弱性 气候变化事实与影响
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作者单位: Sorbonne Universités (UPMC, Univ Paris 06)-CNRS-IRD-MNHN, LOCEAN Laboratory, IPSL, Paris, France; Indo-French Cell for Water Sciences, IISc-NIO-IITM–IRD Joint International Laboratory, IITM, Pune, India; Centre for Climate Change Research, Indian Institute of Tropical Meteorology, Pune, India
Recommended Citation:
Crétat J.,Terray P.,Masson S.,et al. Intrinsic precursors and timescale of the tropical Indian Ocean Dipole: insights from partially decoupled numerical experiment[J]. Climate Dynamics,2018-01-01,51(4)