Difference between revisions of "GEOS-Chem nested grid simulations"
(New page: == Nested Grid Frequently Asked Questions == Q. Can I run a nested grid for GEOS-5 in v8-01-01? A. Not yet. However, Yuxuan Wang and Dan Chen have been working on this capability and we...) |
(No difference)
|
Revision as of 14:21, 8 May 2008
Contents
Nested Grid Frequently Asked Questions
Q. Can I run a nested grid for GEOS-5 in v8-01-01?
A. Not yet. However, Yuxuan Wang and Dan Chen have been working on this capability and we anticipate that it will be ready in a near future release of GEOS-Chem.
Q. Which nested grids are available for me to use?
A. At present, you can use the following nested grids:
Setting up a China nested-grid simulation
Here is a check list and input.geos file that you need to run the nested-grid China simulation (supplied by Yuxuan Wang):
define.h
These are the settings you need to make in the GEOS-Chem define.h file:
#define GEOS_3 'GEOS_3' #define GRID1x1 'GRID1x1' #define NESTED_CH 'NESTED_CH' #define GRID30LEV 'GRID30LEV'
input.geos
These are the settings you need to make in the GEOS-Chem input.geos file:
Saving out 4 x 5 boundary conditions
You will have to run the global model at 4 x 5 resolution to save out the transport boundary conditions. Here are the relevant settings in input.geos:
%%% SIMULATION MENU %%% : Start YYYYMMDD, HHMMSS : 20010101 000000 End YYYYMMDD, HHMMSS : 20020101 000000 Run directory : ./ Input restart file : restart.YYYYMMDDhh Make new restart file? : F Output restart file(s) : restart.YYYYMMDDhh Root data directory : /data/ctm/GEOS_4x5/ => GCAP subdir : AGRID/YYYY/MM/ => GEOS-3 subdir : GEOS_3/YYYY/MM/ => GEOS-4 subdir : GEOS_4_v4/YYYY/MM/ => GEOS-5 subdir : GEOS_5/YYYY/MM/ Dir w/ 1x1 emissions etc: /data/ctm/GEOS_1x1/ Temporary directory : TEMP/ Unzip met fields? : T Wait for met fields? : T Use variable tropopause : N Global offsets I0, J0 : 0 0 ... %%% TRANSPORT MENU %%% : Turn on Transport : T => Use Flux Correction?: F => Fill Negative Values: T => IORD, JORD, KORD : 3 3 7 Transport Timestep [min]: 30 Use strat O3/NOy BC's : T ... %%% CONVECTION MENU %%% : Turn on Cloud Conv? : T Turn on PBL Mixing? : T Convect Timestep (min) : 30 ... %%% NESTED GRID MENU %%%: Save TPCORE 4x5 BC's : T TPCORE 4x5 BC directory : /as/home/ctm/yxw/bc/bc_ozone_std/ 4x5 BC timestep [min] : 180 LL box of 4x5 BC region : 51 21 UR box of 4x5 BC region : 67 37 1x1 offsets I0_W, J0_W : 3 3
1x1 nested grid simulation
Then once you have saved out the 4 x 5 boundary conditions you can do the 1 x 1 nested grid simulation. Here are the appropriate settings in input.geos:
%%% SIMULATION MENU %%% : Start YYYYMMDD, HHMMSS : 20010301 000000 End YYYYMMDD, HHMMSS : 20010302 000000 Run directory : ./ Input restart file : restart.YYYYMMDDhh Make new restart file? : F Output restart file(s) : restart.YYYYMMDDhh Root data directory : /data/geos/GEOS_1x1_CH/ => GCAP subdir : AGRID/YYYY/MM/ => GEOS-3 subdir : GEOS_3/YYYY/MM/ => GEOS-4 subdir : GEOS_4_v4/YYYY/MM/ => GEOS-5 subdir : GEOS_5/YYYY/MM/ Dir w/ 1x1 emissions etc: /data/ctm/GEOS_1x1/ Temporary directory : TEMP/ Unzip met fields? : T Wait for met fields? : T Use variable tropopause : F Global offsets I0, J0 : 250 79 # need to be changed for NA; index refer to 1x1 resolution ... %%% TRANSPORT MENU %%% : Turn on Transport : T => Use Flux Correction?: F => Fill Negative Values: T => IORD, JORD, KORD : 3 3 7 Transport Timestep [min]: 10 Use strat O3/NOy BC's : T ... %%% CONVECTION MENU %%% : Turn on Cloud Conv? : T Turn on PBL Mixing? : T Convect Timestep (min) : 10 ... %%% NESTED GRID MENU %%% Save TPCORE 4x5 BC's : T TPCORE 4x5 BC directory : /as/home/strat/yxw/bc/ # change to be your own directory 4x5 BC timestep [min] : 180 LL box of 4x5 BC region : 51 21 # need to be changed for NA; index refer to 4x5 resolution UR box of 4x5 BC region : 67 37 # need to be changed for NA; index refer to 4x5 resolution 1x1 offsets I0_W, J0_W : 3 3 # do not change for NA
NOTES
General
- If not NESTED_CH (East Asia window) or NESTED_NA (north America window), need to first obtain
- The 1x1 meteorological field for the nested domain;
- Tll the input files (mostly emissions) at 1x1 resolution for the nested domain.
- There needs to be two run directories: one for the 4x5 global run and one for the 1x1 nested run
- Only one code directory is necessary. Code version v7-01-02 and higher can be compiled for both the global run and the nested run
- Run the 4x5 global simulation first. With correct switches in the 4x5 input.geos file, boundary conditions will
- be saved out automatically into the designated directory and will be read later by the nested run.
- The code automatically takes care of formatting.
Code
- Change grid size in define.h
- Change scaling factor in lightning_nox_mod.f (if not Chinese window)
- search for 1x1 in the file to locate the lines of code where changes should be made
- Change IGLOB, JGLOB in CMN_SIZE (if not Chinese window)
- IGLOB and JGLOB refers to the size of the nested window measured at 1x1 resolution
- Change PARAMETER( NLAND=2681, NPULSE=3 ) in commsoil.h (if not Chinese window)
- changes are already made in the code; just uncomment the NA part
- Change datadir for O3 column in toms_mod.f --- if not CHINA or NA windows
- need to create TOMS_O3col_2001.geos file at 1x1 resolution for the nested region
- use the IDL code: regrid_4to1_O3_column.pro (note that line 33 and 34 needs to be modified for NA)