Convective and shear-induced turbulence in the deep Kane Gap - Archive ouverte HAL Access content directly
Journal Articles Journal of Geophysical Research. Oceans Year : 2013

Convective and shear-induced turbulence in the deep Kane Gap


The boundary layer above a 4569 m deep slope in the near-equatorial N-Atlantic Ocean Kane Gap, a through-flow for Antarctic Bottom Water (AABW), is characterized by two distinct turbulent regimes that differ by an order of magnitude in intensity depending on the direction of through-flow. During south- and downward flow, vertical mixing is vigorous (resulting for a representative case-study in two-day mean and 6-132 m above the bottom averaged dissipation rate of ε = 2.1±1×10-9 W kg-1 and eddy diffusivity of Kz = 7±4×10-4 m2 s-1). The mixing is across relatively large vertical overturns. During north- and upward flow, smaller overturns are more horizontal as in stratified shear flow (with representative two-day mean ε = 6±3×10-11 W kg-1, Kz = 4±2×10-5 m2 s-1). Stratification is approximately the same during both flow-directions. Although the different turbulence regimes are partially associated with frictional boundary layers of large-scale flows above sloping topography, but not with those over flat bottoms, and partially with flow across a hill-promontory, internal waves are a dominant process in promoting turbulence. In addition, internal waves are observed to push stratification towards the bottom thereby importantly contributing to the mixing of AABW.
Fichier principal
Vignette du fichier
VANHAREN_JGR_2013.pdf (934.1 Ko) Télécharger le fichier
Origin : Publisher files allowed on an open archive

Dates and versions

hal-00880518 , version 1 (13-04-2016)



H. van Haren, E. Morozov, Louis Gostiaux, Roman Tarakanov. Convective and shear-induced turbulence in the deep Kane Gap. Journal of Geophysical Research. Oceans, 2013, 118 (11), pp.5924-5930. ⟨10.1002/2013JC009282⟩. ⟨hal-00880518⟩
223 View
109 Download



Gmail Facebook X LinkedIn More