DOI: 10.1002/2017JC013640
Scopus记录号: 2-s2.0-85040712736
论文题名: Mechanisms of Mixed-Layer Salinity Seasonal Variability in the Indian Ocean
作者: Köhler J. ; Serra N. ; Bryan F.O. ; Johnson B.K. ; Stammer D.
刊名: Journal of Geophysical Research: Oceans
ISSN: 21699275
出版年: 2018
卷: 123, 期: 1 起始页码: 466
结束页码: 496
语种: 英语
英文关键词: annual variability
; eddy-resolving simulation
; Indian Ocean mixed-layer salinity budget
; observations
; SMOS
Scopus关键词: advection
; advection-diffusion equation
; annual variation
; diffusion
; eddy
; ensemble forecasting
; entrainment
; evaporation
; mixed layer
; numerical model
; oceanic circulation
; precipitation (climatology)
; resolution
; runoff
; salinity
; satellite imagery
; sea surface salinity
; seasonal variation
; SMOS
; upwelling
; Bay of Bengal
; Indian Ocean
; Indian Ocean
英文摘要: Based on a joint analysis of an ensemble mean of satellite sea surface salinity retrievals and the output of a high-resolution numerical ocean circulation simulation, physical processes are identified that control seasonal variations of mixed-layer salinity (MLS) in the Indian Ocean, a basin where salinity changes dominate changes in density. In the northern and near-equatorial Indian Ocean, annual salinity changes are mainly driven by respective changes of the horizontal advection. South of the equatorial region, between 45°E and 90°E, where evaporation minus precipitation has a strong seasonal cycle, surface freshwater fluxes control the seasonal MLS changes. The influence of entrainment on the salinity variance is enhanced in mid-ocean upwelling regions but remains small. The model and observational results reveal that vertical diffusion plays a major role in precipitation and river runoff dominated regions balancing the surface freshwater flux. Vertical diffusion is important as well in regions where the advection of low salinity leads to strong gradients across the mixed-layer base. There, vertical diffusion explains a large percentage of annual MLS variance. The simulation further reveals that (1) high-frequency small-scale eddy processes primarily determine the salinity tendency in coastal regions (in particular in the Bay of Bengal) and (2) shear horizontal advection, brought about by changes in the vertical structure of the mixed layer, acts against mean horizontal advection in the equatorial salinity frontal regions. Observing those latter features with the existing observational components remains a future challenge. © 2018. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/114740
Appears in Collections: 气候减缓与适应
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作者单位: Institute of Oceanography, Centrum für Erdsystemforschung und Nachhaltigkeit, University of Hamburg, Hamburg, Germany; National Center for Atmospheric Research, Boulder, CO, United States; Marine, Earth, and Atmospheric Sciences, North Carolina State University, Raleigh, NC, United States
Recommended Citation:
Köhler J.,Serra N.,Bryan F.O.,et al. Mechanisms of Mixed-Layer Salinity Seasonal Variability in the Indian Ocean[J]. Journal of Geophysical Research: Oceans,2018-01-01,123(1)