Abstract
Density currents with cold air circulation are analytically investigated in a 2-dimensional model. Both the propagation speed and depth of density currents are shown to be unaffected by the direction of the cold air circulation for any vorticity distribution. In particular, the propagation speed and depth are explicitly calculated for the case of small vorticities of the cold and warm air masses. The result shows that they increase with the cold air vorticity irrespective of its sign to the leading order approximation. Consistent with the previously published results, they increase also with the warm air vorticity when the vertical integral of the far upstream warm air velocity relative to the ground value is positive.
