1. Nonhydrostatic Global Circulation Model ICON A joint model development of DWD and MPI-M

2. Goal of ICON Develop a new global weather forecast and climate simulation model on the icosahedral- hexagonal grid and solving the fully compressible nonhydrostatic equations with a local zooming option.

3. NP=3 NP=4 NP=5 Orange cut grids

4. Edges grid Edges grid Order3 Order 2 Redundancy 19:9Redundancy 6:5 or 5:5 Grid Stencils Baumgardner

5. Area grid Area grid Order3 Order 1 (Finite Volume) Redundancy 13:9Redundancy 4:3 Grid Stencils Baumgardner

6. Shallow water tests of icosahedral grid: Triangular c-grid version: order 1 or 2, staggered, finite volume method 3rd order version: great circle grid, third order spatial approximation, unstaggered 3-d (hydrostatic) expected for 2008); finite difference method Current state: