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Trevor J. McDougall and Raffaele Ferrari

buoyancy budget for a complete ocean basin and showed that net upwelling requires that the area integral of the magnitude of the dianeutral diffusive buoyancy flux must increase with height, but their study did not shed any light on the physical balance that drives the dianeutral upwelling in the bottom boundary layer. In this way, Klocker and McDougall (2010) derived the buoyancy budget (Walin method) for the net upwelling across isopycnals but did not consider the downwelling and upwelling

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Sih-Yu Chen and Shih-Nan Chen

-dimensional numerical modeling study. ML12 reported that a few days after the onset of downwelling-favorable wind, the cross-shore circulation within the bottom-attached coastal currents exhibited surface offshore and bottom onshore flow structure (termed upwelling circulation hereinafter). This circulation pattern is opposite to what is expected from the Ekman dynamics (e.g., Ekman 1905 ; Estrade et al. 2008 ). Another two-dimensional modeling study by Shcherbina and Gawarkiewicz (2008) reported a similar

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P. F. Choboter, Dana Duke, J. P. Horton, and Paul Sinz

emphasized, for example, the cross-shore movement of the upwelling front ( Austin and Lentz 2002 ), the dependence upon the turbulence submodel ( Allen et al. 1995 ), and the shelf width effect on the shutdown of the bottom boundary layer ( Oke and Middleton 2000 ). The dynamics of downwelling have been studied by Allen and Newberger (1996) using a two-dimensional numerical model. They show that downwelling winds produce a region of well-mixed fluid inshore of a downwelling front and they observe near

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Trevor J. McDougall and Raffaele Ferrari

have shown that most of the diapycnal mixing activity in the deep ocean occurs above rough bottom topography and is bottom intensified with an e -folding height above the bottom with a typical vertical e -folding length scale of ~500 m ( Kunze et al. 2006 ). The decrease of the magnitude of the diapycnal buoyancy flux with height above the bottom causes a downwelling diapycnal velocity, and this raises the question of how AABW can upwell across isopycnals when the diapycnal mixing activity

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Gianluca Meneghello, John Marshall, Mary-Louise Timmermans, and Jeffery Scott

where internal ice stresses prevent the pack from freely moving in response to wind forcing. In this case, the friction between the anticyclonic surface ocean geostrophic flow and a relatively stationary sea ice pack gives rise to upwelling (in opposition to downwelling that would arise for the same wind forcing in the absence of sea ice). Indeed, in situ observations from moorings and ice-tethered profilers (ITPs) show current speeds that can be larger than the ice speed, as detailed in the

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Ricardo P. Matano and Elbio D. Palma

1. Introduction The term “downwelling currents” refers to currents with a downslope mass flux in the bottom boundary layer (BBL). They are also known as cyclonic currents because they flow in the direction of the coastally trapped waves. Examples are the Malvinas and Southland Currents in the Southern Hemisphere and the Oyashio in the Northern Hemisphere. Paradoxically, many of these currents generate the same kind of highly productive ecosystems usually associated with upwelling regimes. The

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Jay A. Austin and Steven J. Lentz

1. Introduction Wind-driven currents play a major role in circulation in coastal regions around the world ( Smith 1995 ). Upwelling and downwelling circulations are of particular interest because of the role their secondary, cross-shelf, circulation plays in redistributing not only heat and salt (and hence density) but also nutrients and biological fields. In this paper, we consider the response to upwelling- and downwelling-favorable winds of a shelf that initially has a strong midwater

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H. J. Niebauer, Theodore Green, and Robert A. Ragotzkie

918 JOURNAL OF PHYSICAL OCEANOGRAPHY VOLUME?Coastal Upwelling/Downwelling Cycles in Southern Lake Superior~H. J. NIEBAUER:, TttEODOKE GRw. w.N A~D ROBW. RT A. RACOTZKmMarin, $tudie~ Center, University of Wisconsin, Madison 53706(Manuscript received 18 February 1977, in revised form 30 May 1977) Extensive current meter, hydrographic and wind data were collected, in the region of the KeweenawCurrent, a

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Zhaoyun Chen, Yuwu Jiang, Jia Wang, and Wenping Gong

entrainment occurs at its offshore edge in an initially unstratified water column ( Fong and Geyer 2001 ; Lentz 2004 ). The upwelling-favorable wind-driven current competes with the buoyancy-driven current, which determines the along-shelf transport of plume water ( Whitney and Garvine 2005 ). Even though forced by a downwelling-favorable wind, the steepened isopycnals compress the buoyant coastal current and cross-shore upwelling circulation occurs ( Chen and Chen 2017 ). Although the dynamics of river

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J. O. Blanton

J~t~ut~R-1975 J. O. BLANTONNearshore Lake Currents Measured During Upwelling andDownwelling of the Thermocline in Lake Ontario j. O. BLANTOtq~Canada Centre for Inland Waters, Burlington, Ontario, Canada(Manuscript received 31 January 1974, in revised form 11 July 1974)ABSTRACT The upwelling-downwelling cycles observed along the north shore of Lake Ontario have periods of about12 to 16 days in length. Currents associated with the downwelling

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