DOI: 10.1002/2017JC013396
Scopus记录号: 2-s2.0-85043457971
论文题名: Mesoscale and Submesoscale Processes in the Southeast Atlantic and Their Impact on the Regional Thermohaline Structure
作者: Capuano T.A. ; Speich S. ; Carton X. ; Blanke B.
刊名: Journal of Geophysical Research: Oceans
ISSN: 21699275
出版年: 2018
卷: 123, 期: 3 起始页码: 1937
结束页码: 1961
语种: 英语
英文关键词: Cape Basin water masses
; Indo-Atlantic exchange
; meso- and submesoscale dynamics
Scopus关键词: anticyclone
; baroclinic instability
; global ocean
; heat transfer
; instability
; intermediate water
; mesoscale eddy
; mixed layer
; mode water
; numerical model
; oceanic circulation
; thermocline
; thermohaline structure
; turbulence
; water exchange
; water mass
; winter
; Agulhas Current
; Atlantic Ocean
; Atlantic Ocean (Southeast)
; Cape Basin
; Indian Ocean
英文摘要: The turbulent processes in the Cape Basin, the southeasternmost gate of the Atlantic Ocean, play a key role in the transport and mixing of upper to intermediate water masses entering the area from the Indian Ocean, making them especially relevant for the Indo-Atlantic transfer of heat and salt. In this paper, two numerical simulations at different horizontal resolutions are used to study mesoscale and submesoscale dynamics, their phenomenology, their evolution, and their impact on the local water masses. Submesoscale processes seasonally affect both, the upper and intermediate layers, but there are clear dynamical differences between the two layers. Several types of instabilities underline this spatial and temporal variability. Near the surface, mixed layer instabilities occur during winter, while mesoscale-driven instabilities, as the symmetric type, prevail in summer. The connection between these two seasonal regimes is ensured, in anticyclonic eddies and within the mixed layers, by Charney baroclinic instabilities, involved in the local formation and subduction of mode water, that we have dubbed as Agulhas Rings mode water. Intermediate depths are instead characterized by mesoscale mechanisms of density compensation and lateral stirring of the tracer variance, triggering a significant filamentogenesis whose vertical scales are comparable to those mentioned in previous studies. This leads to a particularly efficient mixing of Antarctic Intermediate Waters of Indian and Atlantic origins. Lagrangian estimates highlight the new and significant role of fine scale structures in setting the water masses properties of upper and lower thermocline waters materializing the Indo-Atlantic exchange and therefore potentially affecting the global ocean circulation. © 2018. American Geophysical Union. All Rights Reserved.
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/114409
Appears in Collections: 气候减缓与适应
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作者单位: LOPS-UBO, Laboratoire d'Oceanographie Physique et Spatiale, Brest, France; Laboratoire de Meteorologie Dynamique, LMD-IPSL, Ecole Normale Superieure, Paris, France
Recommended Citation:
Capuano T.A.,Speich S.,Carton X.,et al. Mesoscale and Submesoscale Processes in the Southeast Atlantic and Their Impact on the Regional Thermohaline Structure[J]. Journal of Geophysical Research: Oceans,2018-01-01,123(3)