气候变化领域集成服务门户(CCPortal): On the Generation and Salinity Impacts of Intraseasonal Westward Jets in the Equatorial Indian Ocean

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DOI	10.1029/2020JC016066
	On the Generation and Salinity Impacts of Intraseasonal Westward Jets in the Equatorial Indian Ocean
	Nyadjro E.S.; Rydbeck A.V.; Jensen T.G.; Richman J.G.; Shriver J.F.
发表日期	2020
ISSN	21699275
卷号	125 期号:6
英文摘要	While westerly winds dominate the equatorial Indian Ocean and generate the well-known eastward flowing Wyrtki Jets during boreal spring and fall, there is evidence of a strong westward surface jet during winter that is swifter than eastward currents during that season. A weaker westward jet is found in summer. In this study, we report the occurrence, characteristics, and intraseasonal variability of this westward jet and its impact on mixed layer salinity in the equatorial Indian Ocean using the HYbrid Coordinate Ocean Model (HYCOM) reanalysis with the Navy Coupled Ocean Data Assimilation (NCODA). The westward jet typically occurs in the upper 50 m, above an eastward flowing equatorial undercurrent, with peak westward volume transport of approximately −8 Sv. The westward jet builds up gradually, decays rapidly, and is primarily forced by local intraseasonal wind stress anomalies generated by atmospheric intraseasonal convection. Westward acceleration of the jet occurs when the dominant intraseasonal westward wind anomaly is not balanced by the zonal pressure gradient (ZPG) force. The intraseasonal westward jet generates strong horizontal advection and is the leading cause of mixed layer freshening in the western equatorial Indian Ocean. Without it, a saltier mixed layer would persist and weaken any barrier layers. Existing barrier layers are strengthened following the passage of freshwater-laden westward jets. Deceleration of the westward jet occurs when the eastward ZPG becomes increasingly important and the westward intraseasonal wind anomalies weaken. A rapid reversal of atmospheric intraseasonal convection-driven surface winds eventually terminates the westward jet. ©2020. American Geophysical Union. All Rights Reserved.
英文关键词	Indian Ocean; intraseasonal oscillations; intraseasonal variability; mixed layer salinity; surface currents; westward Jet
语种	英语
来源期刊	Journal of Geophysical Research: Oceans
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/186836
作者单位	Department of Physics, University of New Orleans, New Orleans, LA, United States; Now at Northern Gulf Institute, Mississippi State University, Stennis Space Center, MS, United States; Naval Research Laboratory, Stennis Space Center, MS, United States; Center for Ocean-Atmospheric Prediction Studies, Florida State University, Tallahassee, FL, United States
推荐引用方式 GB/T 7714	Nyadjro E.S.,Rydbeck A.V.,Jensen T.G.,et al. On the Generation and Salinity Impacts of Intraseasonal Westward Jets in the Equatorial Indian Ocean[J],2020,125(6).
APA	Nyadjro E.S.,Rydbeck A.V.,Jensen T.G.,Richman J.G.,&Shriver J.F..(2020).On the Generation and Salinity Impacts of Intraseasonal Westward Jets in the Equatorial Indian Ocean.Journal of Geophysical Research: Oceans,125(6).
MLA	Nyadjro E.S.,et al."On the Generation and Salinity Impacts of Intraseasonal Westward Jets in the Equatorial Indian Ocean".Journal of Geophysical Research: Oceans 125.6(2020).