A. Männik, R. Rõõm
The paper describes the numerical model of atmospheric dynamics, designed as the nonhydrostatic extension to the hydrostatic kernel of HIRLA. The theoretical concept, initiated in Part I, is brought to numerical codes. The anelastic hybrid-coordinate model is formulated both in the continuous and discrete representations, and the numerical code with the explicit-Eulerian time stepping scheme is implemented in the HIRLA environment. In the development of numerical code, the main attention is paid to the creation of the elliptic solver for the baric geopotential equation. For this, an orthogonal basis is applied in all three coordinates, including the vertical hybrid coordinate. The nonhomogeneous boundary conditions are handled by introduction of singular sources on lateral and bottom boundaries. The paper ends with numerical examples, demonstrating the capabilities of the model. The maximum horizontal resolution of the model is approximately 0.5 km. Due to the application of surface pressure adjustment, the accessible time step is rather large (60 s at the 11 km, 40-50 s at the 2.2 km, and 20-30 s at the 1 km resolution) and makes the model applicable in high-resolution simulations.