A two-dimensional, nonlinear, time-dependent, non-hydrostatic, anelastic, numerical model is used to assess the effect of condensation on the evolution and structure of gravity waves generated by the passage of a stable, moist stream over topography. Precipitation is ignored but water phase changes are taken into account explicitly. / The numerical approach uses centered finite differences, except for liquid water, which is advected by using an upwind scheme. A constant basic wind and a constant stability are assumed in order to isolate the effects of moisture. At the inflow boundary the wind velocity is kept constant with time, whereas at the outflow boundary, the Orlanski (1976) extrapolation scheme is applied. Spurious reflections from the upper boundary are minimized by an absoring (sponge) layer. As initial conditions we impose an irrotational flow and zero buoyancy, consistent with the physics of impulsively started motions. / Evolution for hydrostatic and non-hydrostatic flows have been studied. For both, the wave field, immediately after the start-up, consists of a V-shaped pattern, similar to that obtained experimentally by Mowbray and Rarity (1967). As time progresses, only the upwind branch of the pattern remains, with new waves piling up above the mountain peak in the hydrostatic case; or forming a stack above and downwind from the mountain peak in the non-hydrostatic case. In both cases, the inclusion of moisture steepens the pattern. / The main effect of condensation is to damp the wave intensity and to reduce the wave drag, which can be diminished by as much as 50% compared to its value in dry simulations. / A breaking wave case has been also studied. It has been found that the presence of condensation delays the overturning of isentropes and the formation of the critical layer that accompanies wave-breaking. / Source: Dissertation Abstracts International, Volume: 45-02, Section: B, page: 0586. / Thesis (Ph.D.)--The Florida State University, 1984.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_75280 |
| Contributors | JUSEM, JUAN CARLOS., Florida State University |
| Source Sets | Florida State University |
| Detected Language | English |
| Type | Text |
| Format | 122 p. |
| Rights | On campus use only. |
| Relation | Dissertation Abstracts International |
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