A 2D Finite Volume Non-hydrostatic Atmospheric Model ...

6.7 Atmosphere at restWe now want to show that our model is able to simulate an atmosphere at rest over steeper topography.The parameters used are listed in table 6.5. We compare the evolution of the maximum magnitude of thehorizontal velocity to the values obtained by Wunderlich in [6]. The grid we use is hybrid with terrainfollowingcoordinates below and uniform coordinates above 12000 m. That's also where our Rayleighsponge layer starts. We make a time integration of 25000 seconds which is about 7 hours. The numberswe get are slightly smaller than those Wunderlich gets in [6], compare figure 6.12 and 6.13. The maindifferences of the two models are the improvements we made, the number of time steps between theevaluation of the local hydrostatic background state and the hybrid grid we use.time integration schemeatmospheremountain heightmountain half widthmountain typehorizontal domain sizevertical domain sizehorizontal cell sizevertical cell size rangenumber of horizontal grid cellsnumber of vertical grid cellsinitial Brunt-Väisälä frequencybottom potential temperatureinitial vertical velocitytime stepintegration timeparameter value unitx-divergence damping coefficientz-divergence damping coefficientAsselin coefficientRayleigh damping coefficientRayleigh damping layer thicknessx-computational mixing coefficientz-computational mixing coefficientleapfrogstratified15005000Gaussian402180030050700.012880.4250000.050.050.050.0290000.0050.005Table 6.5: List of parameters used for the simulation of an atmosphere at rest above steep topography.--mm-kmkmmm--1/sKm/sss----m--37