DOI: 10.1007/s00382-017-3716-8
Scopus记录号: 2-s2.0-85018744950
论文题名: Equatorial Indian Ocean subsurface current variability in an Ocean General Circulation Model
作者: Gnanaseelan C. ; Deshpande A.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2018
卷: 50, 期: 2018-05-06 起始页码: 1705
结束页码: 1717
语种: 英语
英文关键词: Equatorial Indian Ocean
; Equatorial subsurface current
; IOD, El Niño, Wyrtki jet
Scopus关键词: air-sea interaction
; atmosphere-ocean coupling
; computer simulation
; El Nino
; Indian Ocean Dipole
; monsoon
; oceanic circulation
; oceanic current
; oceanic general circulation model
; sea surface temperature
; Indian Ocean
; Indian Ocean (Equatorial)
英文摘要: The variability of subsurface currents in the equatorial Indian Ocean is studied using high resolution Ocean General Circulation Model (OGCM) simulations during 1958–2009. February–March eastward equatorial subsurface current (ESC) shows weak variability whereas strong variability is observed in northern summer and fall ESC. An eastward subsurface current with maximum amplitude in the pycnocline is prominent right from summer to winter during strong Indian Ocean Dipole (IOD) years when air-sea coupling is significant. On the other hand during weak IOD years, both the air-sea coupling and the ESC are weak. This strongly suggests the role of ESC on the strength of IOD. The extension of the ESC to the summer months during the strong IOD years strengthens the oceanic response and supports intensification and maintenance of IODs through modulation of air sea coupling. Although the ESC is triggered by equatorial winds, the coupled air-sea interaction associated with IODs strengthens the ESC to persist for several seasons thereby establishing a positive feedback cycle with the surface. This suggests that the ESC plays a significant role in the coupled processes associated with the evolution and intensification of IOD events by cooling the eastern basin and strengthening thermocline-SST (sea surface temperature) interaction. As the impact of IOD events on Indian summer monsoon is significant only during strong IOD years, understanding and monitoring the evolution of ESC during these years is important for summer monsoon forecasting purposes. There is a westward phase propagation of anomalous subsurface currents which persists for a year during strong IOD years, whereas such persistence or phase propagation is not seen during weak IOD years, supporting the close association between ESC and strength of air sea coupling during strong IOD years. In this study we report the processes which strengthen the IOD events and the air sea coupling associated with IOD. It also unravels the connection between equatorial Indian Ocean circulation and evolution and strengthening of IOD. © 2017, Springer-Verlag Berlin Heidelberg. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/109421
Appears in Collections: 影响、适应和脆弱性 气候变化事实与影响
There are no files associated with this item.
作者单位: Indian Institute of Tropical Meteorology, Pune, 411008, India; Savitribai Phule Pune University, Pune, 411007, India
Recommended Citation:
Gnanaseelan C.,Deshpande A.. Equatorial Indian Ocean subsurface current variability in an Ocean General Circulation Model[J]. Climate Dynamics,2018-01-01,50(2018-05-06)