Sommaire
Domain & resolution
First you should decide if your upon the final(!) simulation (see "Cascading" below) should be on a regional or a global grid and at which domain and resolution you want to run. For this it is important to know that:
- the more grid points a grid has , => the more cores are needed and
- the smaller higher the resolution and with that => the shorter the model timestep => the longer the simulation will take.
Number of points
Resolution → timestep
Cascadeing
Radiation timestep
...
- runtime of the simulation
Have a look at the following wiki about how to set up a model grid: Set up a model grid
Number of points
Topology (MPI & OpenMP)
Resolution → timestep
The relation between the horizontal resolution and the model timestep is linear. Here are some examples:
| Resolution [degree] | Resolution [km] | model timestep [sec] | For GY grid |
|---|---|---|---|
| 0.009° | ~1 km | 30 s | |
| 0.0225° | ~2.5 km | 60 s | |
| 0.036° | ~4 km | 90 s | |
| 0.11° | ~12 km | 300 s | |
| ~25 km | 720 s | Grd_nj = 417 | |
| ~55 km | 1800 s | Grd_nj = 171 |
Resolution → timestep → radiation timestep
Resolution → (non) hydrostatic
Model levels
LAM grid → top piloting or sponge
Global grid → adjust global pressure
Cascadeing
Spectral nudging
Period
Greenhouse gases
Initial conditions
Driving data
Geophysical fields
Schemes
...
Land surface scheme (ISBA, CLASS, SVS)
Lake scheme (non, FLake, CSLM)
Urbain scheme (non, TEB)
...
P3
Bourgouin
...