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Experiment Configuration

In order to design a WRF4G experiment you need to edit a file called experiment.wrf4g. From this file, WRF4G will generate all WRF configuration files required to run the simulations planned for the experiment.

Configuration format

The configuration experiment file consists of sections, each led by a [section] header, followed by key = value entries. Lines beginning with # are ignored. Allowing sections are [DEFAULT] and [resource_name].

DEFAULT section

The DEFAULT section provides default values for all other sections. And its key values are:

Example for one physic and one domain :

namelist_values = single:ra_lw_physics          | 3
                  single:physics.ra_sw_physics  | 3

Example for two physics and two domains :

namelist_label_comb =                         phy1 | phy2
namelist_values     = ra_lw_physics         | 2, 2 | 3, 3
                      ra_sw_physics         | 2, 2 | 3, 3

If several physics are described, you have to use the namelist_label_comb variable to indicate their names.

Resource section

Each resource section has to begin with the line [resource_name] followed by key = value entries. Thus, experiment variables such as clean_after_run, save_wps, real_parallel, wrf_parallel, domain_path, preprocessor, extdata_path, postprocessor, app and output_path can be defined depending on each computing resource. Therefore you can simulate your realizations concurrently on different resources.

How to create one

You can write a experiment.wrf4g from scratch or use the templates that WRF4G provides by typing :

$ wrf4g exp test define --from-template single
$ cat ./test/experiment.wrf4g
[DEFAULT]
# Experiment configuration
name                 = test
# Simulation domain
max_dom              = 1
# Experiment time-specification
#                      start_date          | end_date            | chunk_size_h
date_time            = 2011-08-28_12:00:00 | 2011-08-30_00:00:00 | 12
calendar             = standard
timestep_dxfactor    = 6
# Running options 
np                   = 1
requirements         = ARCH = "x86_64"
clean_after_run      = yes
save_wps             = no
parallel_environment = MPIRUN
parallel_real        = yes
parallel_wrf         = yes
# Input data
domain_path          = /home/carlos/WRF4G_2_0/repository/domains/Santander_50km
# Vtables must exist as Vtable.[input_extdata]
extdata_vtable       = GFS
extdata_path         = /home/user/WRF4G_2_0/repository/input/NCEP/GFS
# Seconds between global analysis input times
extdata_interval     = 21600
preprocessor         = default
# Output
output_path          = /home/user/test/output
postprocessor        = SFC
# app
app                  = wrf_all_in_one | bundle | /home/user/wrf4g/repository/apps/WRF/WRFbin-3.4.1_r2265_gfortran.tar.gz
# WRF-namelist parameters. Override namelist.input variables here
namelist_version     = 3.4.1
namelist_values      = spec_bdy_width     | 10
                       spec_zone          | 1
                       relax_zone         | 9
                       feedback           | 0
                       history_interval   | 180
                       frames_per_outfile | 3
                       e_vert             | 28
                       mp_physics         | 4
                       radt               | 15
                       ra_lw_physics      | 3
                       ra_sw_physics      | 3