engleski

Katabatic flow with Coriolis effect and gradually varying eddy diffusivity

Katabatic flows over high-latitude long glaciers experience the Coriolis force. A sloped atmospheric boundary-layer (ABL) flow is addressed which partly diffuses upwards, and hence, becomes progressively less local. We present the analytical and numerical solutions for (U , V, Theta) depending on (z, t) in the katabatic flow, where U and V are the downslope and cross-slope wind components and Theta is the potential temperature perturbation. A Prandtl model that accounts for the Coriolis effect, via f, does not approach a steady state, because V diffuses upwards in time ; the rest, i.e., (U, Theta ), are similar to that in the classic Prandtl model. The V component behaves in a similar manner as the solution to the 1st Stokes (but inhomogeneous) problem. A WKB approach to the problem of the sloped ABL winds is outlined in the light of a modified Ekman-Prandtl model with gradually varying eddy diffusivity K(z). Ideas for parameterizing these high-latitude persistent flows in climate models are revealed.

low-level jet; Prandtl model; strongly stable boundary layer

DOI 10.1007/s10546-007-9167-8 Rad pripada nekolicini projekata.