Idealized normal-mode baroclinic wave simulations are conducted to examine the impact of continuousmesh refinement compared with stepwise changes in resolution using nested grids. The nested-grid results are produced using theAdvancedResearchWeather Research and Forecasting (WRF-ARW)Model, hereafterARW, and the continuous refinement results are produced using the atmospheric component of the Model for Prediction Across Scales-Atmosphere (MPAS-A). For the nested domain simulations with the ARW, variants of both one-way and two-way nesting techniques are examined. Significant reflection and distortion of waves are evident in results using one-way nesting, with the error increasing with decreasing boundary-update frequency. With continuous updating of the boundary conditions in one-way and two-way nesting, wave distortion is still evident near the lateral boundaries but the distortion is much less than with infrequent boundary updates. The conformal Voronoi meshes inMPAS provide a much smoother transition between mesh resolutions. Variableresolution mesh MPAS-A simulations, using different transition zones between high- and low-resolution regions, are compared with the results from the ARW simulations. In the MPAS-A simulations, there is no significant reflection of gravity waves, suggesting that continuous mesh refinement can eliminate distortions that tend to occur along the boundaries of nested meshes.
All Science Journal Classification (ASJC) codes
- Atmospheric Science