DOI: 10.1007/s00382-016-3234-0
Scopus记录号: 2-s2.0-84975297435
论文题名: Observed variability in the upper layers at the Equator, 90°E in the Indian Ocean during 2001–2008, 1: zonal currents
作者: Rao R.R. ; Horii T. ; Masumoto Y. ; Mizuno K.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2017
卷: 49, 期: 3 起始页码: 1077
结束页码: 1105
语种: 英语
英文关键词: Barrier layer thickness
; Equatorial undercurrent
; Equatorial zonal currents
; Indian Ocean
; Interannual variability
; Intraseasonal variability
; Sea surface temperature
; Westerly wind bursts
英文摘要: The observed variability of zonal currents (ZC) at the Equator, 90°E shows a strong seasonal cycle in the near-surface 40–350 m water column with periodic east–west reversals most pronounced at semiannual frequency. Superposed on this, a strong intraseasonal variability of 30–90 day periodicity is also prominently seen in the near-surface layer (40–80 m) almost throughout the year with the only exception of February–March. An eastward flowing equatorial undercurrent (EUC) is present in the depth range of 80–160 m during March–April and October–November. The observed intraseasonal variability in the near-surface layer is primarily determined by the equatorial zonal westerly wind bursts (WWBs) through local frictional coupling between the zonal flow in the surface layer and surface zonal winds and shows large interannual variability. The eastward flowing EUC maintained by the ZPG set up by the east–west slope of the thermocline remotely controlled by the zonal wind (ZW) and zonally propagating wave fields also shows significant interannual variability. This observed variability on interannual time scales appears to be controlled by the corresponding variability in the alongshore winds off the Somalia coast during the preceding boreal winter, the ZW field along the equator, and the associated zonally propagating Kelvin and Rossby waves. The salinity induced vertical stratification observed in the near-surface layer through barrier layer thickness (BLT) effects also shows a significant influence on the ZC field on intraseasonal time scale. Interestingly, among all the 8 years (2001–2008), relatively weaker annual cycle is seen in both ZC in the 40–350 m water column and boreal spring sea surface temperature (SST) only during 2001 and 2008 along the equator caused through propagating wave dynamics. © 2016, Springer-Verlag Berlin Heidelberg. 资助项目: JAMSTEC, Japan Agency for Marine-Earth Science and Technology
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/53143
Appears in Collections: 过去全球变化的重建
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作者单位: ICMPO, IITM, Pune, India; JAMSTEC, Yokosuka, Japan; University of Tokyo, Tokyo, Japan
Recommended Citation:
Rao R.R.,Horii T.,Masumoto Y.,et al. Observed variability in the upper layers at the Equator, 90°E in the Indian Ocean during 2001–2008, 1: zonal currents[J]. Climate Dynamics,2017-01-01,49(3)