Abstract : 1A.4
High-drag regimes in non-hydrostatic and/or rotating flows past 3D obstacles

Rita Cardoso, Pedro M A Miranda, Miguel Teixeira
Centro de GeofĂ­sica da Universidade de Lisboa

Three-dimensional isolated mountains may force high-amplitude internal waves that modify the atmospheric flow in their vicinity. In the case of circular mountains, or whenever their cross-stream extension is small, the establishment of those high-amplitude waves is only possible for a small range of flow parameters, corresponding to a narrow range of values for Nh/U. That behaviour has been previously studied for hydrostatic non-rotating flow. This work studies the changes that occur when non-hydrostatic and/or rotating effects are taken into account. Both effects tend to increase horizontal dispersion, reducing the amplitude of standing internal waves. However, when appropriately scaled by the corresponding linear solutions, both non-hydrostatic and rotating flows allow for the establishment of high-drag regimes, qualitatively similar to hydrostatic non-rotating solutions, but at slightly different values of Nh/U. Using non-geophysical values of the Coriolis parameters it is possible to look at flow regimes where both non-hydrostatic and rotating effects are simultaneously important.The effects of wind-shear will also be investigated.