DOI: 10.1002/2017JC013582
Scopus记录号: 2-s2.0-85051220542
论文题名: Modulation of the Semidiurnal Cycle of Turbulent Dissipation by Wind-Driven Upwelling in a Coastal Embayment
作者: Fernández-Castro B. ; Gilcoto M. ; Naveira-Garabato A.C. ; Villamaña M. ; Graña R. ; Mouriño-Carballido B.
刊名: Journal of Geophysical Research: Oceans
ISSN: 21699275
出版年: 2018
卷: 123, 期: 6 起始页码: 4034
结束页码: 4054
语种: 英语
英文关键词: coastal upwelling
; Ria
; semidiurnal cycle
; shear instability
; tidal ellipses
; turbulent dissipation
英文摘要: With two 25-hour series of turbulent microstructure and currents observations carried out in August 2013, during spring (CHAOS 1) and neap tides (CHAOS 2), we investigated the semidiurnal cycle of turbulent dissipation in an embayment affected by coastal upwelling (Ría de Vigo, NW Iberia). At the time of sampling, the bay hosted a net, wind-driven bi-directional positive exchange flow and thermal stratification. Turbulent kinetic energy (TKE) dissipation (ɛ) at the interface between upwelled and surface waters was enhanced by two orders of magnitude during the ebbs (~10-6 W kg− 1) with respect to the floods (~10-8 W kg− 1). This pattern was caused by the constructive interference of the shear associated with the upwelling and tidal currents. The vertical structure of the tidal currents was consistent with a deformation of tidal ellipses by stratification, which was tightly coupled to the intensity of upwelling. This two-pronged interaction resulted in a modulation of the semidiurnal cycle of turbulent dissipation by coastal upwelling. Thus, as a result of the upwelling relaxation conditions experienced during CHAOS 1, depth-integrated interior TKE dissipation rates were higher, by a factor of ~2, compared to CHAOS 2. By using a simple model, we determined that observed variations in turbulent mixing had a limited influence on the tidal variations of stratification, which were dominated by straining and advection. The mixing mechanism described here is potentially relevant for the ecology of upwelling bays, as it can stimulate the transport of nutrients from deep-upwelled waters to the sun-lit surface layers where primary production takes place. © 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/113743
Appears in Collections: 气候减缓与适应
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作者单位: Laboratorio de Xeoquímica Orgánica. Instituto de Investigacións Mariñas (IIM-CSIC), Rúa Eduardo Cabello, 6, Vigo, Spain; Grupo de Oceanoloxía. Instituto de Investigacións Mariñas (IIM-CSIC), Rúa Eduardo Cabello, 6, Vigo, Spain; Ocean and Earth Science, University of Southampton, National Oceanography Centre, Southampton, United Kingdom; Departamento de Ecoloxía e Bioloxía Animal, Universidade de Vigo, Vigo, Spain
Recommended Citation:
Fernández-Castro B.,Gilcoto M.,Naveira-Garabato A.C.,et al. Modulation of the Semidiurnal Cycle of Turbulent Dissipation by Wind-Driven Upwelling in a Coastal Embayment[J]. Journal of Geophysical Research: Oceans,2018-01-01,123(6)