Using the Mellor‐Yamada level II closure scheme, a numerical study is made of the bottom boundary layer on a uniform, stratified shelf with slope α. For constant interior along‐slope currents ug and molecular background diffusion, a new timescale for shutdown of bottom stress is derived for the downwelled layer as well as a new estimate for the maximum height of the upwelled layer, hU = (CD/fN)1/2ug(1 + S1/2)−1 where CD = 2.5 × 10−3 is a drag coefficient, f and N are the Coriolis and buoyancy frequencies, and S = (Nα/f)2 is the Burger number. The Richardson number is also shown to fix the thermal‐wind shear at the top of the upwelled layer to be approximately uz≃N(RiS)−1 , while within the layer, a depth‐averaged form of the geostrophic balance is shown to hold. In the case of large interior vertical diffusivities (10−4 m2s−1), the fluxes of momentum and buoyancy into the interior are quantified and shown to result in the arrest (enhancement) of shutdown in the upwelling (downwelling) boundary layers. Advective restratification of mixed water is not found to occur, and for an 8‐day periodic interior current ug(t), the thermal‐wind shear that remains during the downwelling and upwelling phases can result in a 1.2‐day lag of interior current with bottom stress. Bottom stress and the cross‐slope Ekman flux are found to be surprisingly symmetric during the upwelling and downwelling phases of the interior current. The lag with bottom stress and effects of shutdown are shown to persist in the presence of tidal currents and large background diffusion and may well be significant on the continental shelf.

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{{Explor lien
   |wiki=    Sante
   |area=    H2N2V1
   |flux=    Istex
   |étape=   Checkpoint
   |type=    RBID
   |clé=     ISTEX:D3A4A73D27FCDF094F09335F6F4E14A95C2EE2B5
   |texte=   The evolution of the bottom boundary layer on the sloping continental shelf: A numerical study
}}