NUMERICAL SIMULATIONS OF DENSITY CURRENTS IN SHEARED ENVIRONMENTS WITHIN A VERTICALLY CONFINED CHANNEL

Numerical simulations are performed to study the kinematics and dynami cs of nearly inviscid, two-dimensional density currents propagating in a uniformly sheared environmental Row within a vertically confined ch annel. In order to study the physical properties of the numerical solu tions relative to those of theoretical predictions, the initial cold p ool depth and shear are chosen to be either similar to or significantl y different than those prescribed by the theoretical steady-state mode l. The authors find that, regardless of the model initial condition, t he density current front reaches nearly the same quasi-steady state. T he propagation speed, depth, and gross shape. of the density current h ead in the quasi-steady state agree closely with previously published theoretical results and are independent of the initial depth of the co ld pool provided that the total volume of cold air is sufficiently lar ge, Physical interpretation of the results is provided based on theore tical analyses and numerical diagnosis of the energy, vorticity, mass, and momentum conservation properties of the simulated Bows.