A new non-hydrostatic hybrid vertical coordinate atmospheric model

We present a new atmospheric model which is based on the elastic, non-hydrostatic equations of motion using a hybrid vertical coordinate. A height-based, terrain-following coordinate is used near the surface which smoothly transitions to a quasi-Lagrangian (isentropic) coordinate in the free atmosphere. Integral constraints such as total energy and angular momentum conservation are preserved by the vertical differencing scheme. Model test results on various spatial scales are presented, including a simulation of the 11 January 1972 Boulder, Colorado windstorm.