Simulation of atmospheric frontogenesis with a semi-Lagrangian numerical model

Abstract : In this study a numerical model based on the hydrostatic Boussinesq equations is used to simulate atmospheric frontogenesis driven by an irrotational non-divergent deformation wind field. The equations are numerically integrated by using the semi-Lagrangian technique associated with two different time schemes: explicit and semi. Both schemes produce realistic fronts after approximately 40 hours of model integration. The semi-Lagrangian semi-implicit scheme is more successful in handling the sharp gradients associated with the front. Also, the semi-Lagrangian semi-implicit equations are integrated with time steps as long as 3600 sec. producing solutions with relatively small errors. This indicates that this numerical scheme is appropriate for use in mesoscale regional models.