Ezer, T., and G. L. Weatherly, 1990: A numerical study of the interaction
between a deep cold jet and the bottom boundary layer of the ocean.
Journal of Physical Oceanography, 20(6), 801-816.
Abstract: A two-dimensional (x-z) primitive equation model
is used to study the interaction between a deep cold jet on a sloping bottom
and the bottom boundary layer (BBL) of the deep ocean. Two closure schemes
are used: a standard second order turbulence closure (SOTC) scheme (the
level 2-1/2 model of Mellor and Yamada), and a new eddy viscosity closure
scheme (K- model). The latter is a computationally simple model that produces
very similar eddy viscosity and velocity fields as the more complicated
SOTC-model while saving about 20% ot the computational time.
The results of the numerical simulations compare favorably to observations
from the base of the North Atlantic continental rise where the cold jet
known as the Cold Filament (CF) is found. The interaction between the CF
and the BBL is found to be dominated by cross-isotherm Ekman flow, resulting
in an asymmetry effect with different dynamics at each one of the fronts
associated with the CF. Some of the unusual characteristics of this region
are explained with the aid of the numerical experiments. These are: velocity
profiles significantly different from those obtained by classical Ekman
dynamics, unstable BBLs and detachment of bottom layers. Spatial variations
in the characteristics of the BBL which are often neglected in deep-ocean
studies are found to be significant in this region.