Difference between revisions of "Advanced Use of the GCM"
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== How to Change Vertical and Horizontal Resolutions == | == How to Change Vertical and Horizontal Resolutions == | ||
| + | === When you are using the regular longitude/latitude horizontal grid === | ||
To run at a different grid resolution than available initial conditions files, one needs to use the tools ''newstart.e'' and ''start2archive.e'' | To run at a different grid resolution than available initial conditions files, one needs to use the tools ''newstart.e'' and ''start2archive.e'' | ||
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* Create files ''restart.nc'' and ''restartfi.nc'' with ''newstart.e'' compiled at grid resolution 32×24×25, using a new file ''z2sig.def'' (more details below on the choice of the ''z2sig.def'') | * Create files ''restart.nc'' and ''restartfi.nc'' with ''newstart.e'' compiled at grid resolution 32×24×25, using a new file ''z2sig.def'' (more details below on the choice of the ''z2sig.def'') | ||
| − | === What you need to ''know'' about the ''z2sig.def'' file (change of vertical resolution only) === | + | ==== What you need to ''know'' about the ''z2sig.def'' file (change of vertical resolution only) ==== |
TO BE COMPLETED | TO BE COMPLETED | ||
<!-- [NOT RELEVANT??] If you want to create starts files with tracers for 50 layers using a start archive.nc obtained for 32 layers, do not forget to use the ini_q option in newstart in order to correctly initialize tracers value for layer 33 to layer 50. You just have to answer yes to the question on thermosphere initialization if you want to initialize the thermosphere part only (l=33 to l=50), and no if you want to initialize tracers for all layers (l=0 to l=50). --> | <!-- [NOT RELEVANT??] If you want to create starts files with tracers for 50 layers using a start archive.nc obtained for 32 layers, do not forget to use the ini_q option in newstart in order to correctly initialize tracers value for layer 33 to layer 50. You just have to answer yes to the question on thermosphere initialization if you want to initialize the thermosphere part only (l=33 to l=50), and no if you want to initialize tracers for all layers (l=0 to l=50). --> | ||
| + | |||
| + | |||
| + | === When you are using the regular longitude/latitude horizontal grid === | ||
| + | |||
| + | |||
| + | |||
| + | On run_icosa.def: | ||
| + | |||
| + | nbp --> number of subdivision on a main triangle: integer (default=40) | ||
| + | nbp = sqrt((nbr_lat x nbr_lon)/10) | ||
| + | nbp 20 40 80 160 | ||
| + | T-edge length (km) 500 250 120 60 | ||
| + | Example: nbp(128x96)=35 -> 40 | ||
| + | nbp(256x192)=70 -> 80 | ||
| + | nbp(360x720)=160 -> 160 | ||
| + | nsplit_i, nsplit_j --> sub splitting of main rhombus: integer | ||
| + | Example: for nbp=80, nsplit_i=4,nsplit_j=6 | ||
| + | nbp/nsplit_{i,j} = 20 > 10 & 13 > 10 --> GOOD | ||
| + | |||
| + | |||
| + | - Remapping | ||
| + | |||
| + | Pour le remapping, il faut aller dans context_lmdz_physics.xml changer les paramètres ni_glo et nj_glo par exemple pour remapper sur du lat/lon à 360 pts en latitude et 720 pts en longitude (0.5°). | ||
| + | |||
| + | |||
| + | <domain id="dom_regular" ni_glo="720" nj_glo="360" type="rectilinear"> | ||
== How to Change the Topography (or remove it) == | == How to Change the Topography (or remove it) == | ||
Revision as of 11:26, 11 May 2022
Contents
Running in parallel
For large simulation (long run, high resolution etc...), the waiting time can becomes very long. To overcome this issue, the model can works in parallel. It first needs to be compiled in parallel mode and then be run with a specific command. For all the details see the dedicated page Parallelism
Distinctions beween ifort, mpi, etc.
TO BE COMPLETED BWAAAAA
Distinction between using IOIPSL or XIOS
TO BE COMPLETED
How to Change Vertical and Horizontal Resolutions
When you are using the regular longitude/latitude horizontal grid
To run at a different grid resolution than available initial conditions files, one needs to use the tools newstart.e and start2archive.e
For example, to create initial states at grid resolution 32×24×25 from NetCDF files start and startfi at grid resolution 64×48×32 :
- Create file start_archive.nc with start2archive.e compiled at grid resolution 64×48×32 using old file z2sig.def used previously
- Create files restart.nc and restartfi.nc with newstart.e compiled at grid resolution 32×24×25, using a new file z2sig.def (more details below on the choice of the z2sig.def)
What you need to know about the z2sig.def file (change of vertical resolution only)
TO BE COMPLETED
When you are using the regular longitude/latitude horizontal grid
On run_icosa.def:
nbp --> number of subdivision on a main triangle: integer (default=40)
nbp = sqrt((nbr_lat x nbr_lon)/10)
nbp 20 40 80 160
T-edge length (km) 500 250 120 60
Example: nbp(128x96)=35 -> 40
nbp(256x192)=70 -> 80
nbp(360x720)=160 -> 160
nsplit_i, nsplit_j --> sub splitting of main rhombus: integer
Example: for nbp=80, nsplit_i=4,nsplit_j=6
nbp/nsplit_{i,j} = 20 > 10 & 13 > 10 --> GOOD
- Remapping
Pour le remapping, il faut aller dans context_lmdz_physics.xml changer les paramètres ni_glo et nj_glo par exemple pour remapper sur du lat/lon à 360 pts en latitude et 720 pts en longitude (0.5°).
<domain id="dom_regular" ni_glo="720" nj_glo="360" type="rectilinear">
How to Change the Topography (or remove it)
The generic model can use in principle any type of surface topography, provided that the topographic data file is available in the right format, and put in the right place.
How to Change the Opacity Tables
TO BE COMPLETED
How to Manage Tracers
Tracers are managed thanks to the traceur.def file.
Specific treatment of some tracers (e.g., water vapor cycle) can be added directly in the model and an option added in callphys.def file.
