Computational Science Community Wiki

WRFCHEM Namelist Options

Further Reading

Much of the following is based on the WRF-Chem user guides. For more information on these topics, please use the following links:

Base Namelist

These are the standard namelist.input options to be used

RONOCO Summer Campaign Namelist

This is the namelist for the single Domain run, the restart files from which will be used for all the nested domain runs.

How To Define Time Control And Domains In The Namelist File

How to implement the adaptive time step option

Physics Parameterisations - Identified Problems and Recommendations

The following is a series of recommendations physics options thus far identified when using WRf-Chem version 3.2.1 with Crimech gas phase chemistry and Mosaic aerosol (chem_opt = 401). The current recommended physics parameterisations for running the UK domain in summer are as follows (for set-up with parent grid dx~15km, first nest dx~5km, second nest dx~1.6km, SAN 10/10/11):

   scaler_adv_opt = 2,

Chemistry Options

running with biomass burning emissions

BUG WARNING: If using MOSAIC aerosol, please use the Manchester house developed version of WRF-chem, or the emissions will not be read in correctly.

Prior to running WRf-chem, you will have needed to create wrffire_chemi files for each domain and day you are running for, using PREP-chem and convert_emiss.

Set the following options in the namelist:

auxinput7_inname                    = 'wrffirechemi_d<domain>_<date>', 
auxinput7_interval_m                = 1440,
frames_per_auxinput7                = 1,
io_form_auxinput7                   = 2,

 biomass_burn_opt                    = 1,
 plumerisefire_frq                   = 30,

 bburn_diurnal                       = .true.,

How To Set-up For Nesting

When using nesting with WRF-Chem, make sure WRF-Chem is compiled for nesting (select 1 = basic when running configure before you compile WRF-Chem).

Setting up the WPS for nesting

The convention for writing namelists with nests is to write the value for each variable for the outermost nest first, with the value for each further nest separated by commas. Not all variables need to be defined for each nest. Check the files registry.wrfvar and registry.chem; all variables with dimension = max_domains need to be set for each domain.

Running concurrent nests

As for the namelist.wps, when running multiple domains at the same time the namelist must be edited with multiple columns for many variables.

 grid_id = 1, 2, 3, ... 

nested = .false., .true, ...

In general, the physics and chemistry options should be set to be the same for each domain. Make sure  progn = 1, 1, ...  if using  mp_physics = 2 . The possible exceptions to this rule are as follows:

Changes in namelist from v3.2 to v3.3.1

Special options for long simulations

      sst_update                          = 1,

                                        &time_control
                                       .
                                       .
                                       .
                                       auxinput4_inname                    = "wrflowinp_d<domain>",
                                       auxinput4_interval                  = 360,360,
                                       io_form_auxinput4                   = 2,

      usemonalb                           = .true.,

     tmn_update                          = 1,

     sst_skin                            = 1,

     bucket_mm = 100 or whatever value

Problem running sst_update=1 with feedback

!!! Note - these problems only seem to occur when the inner nest starts at a different time to the outer nest - test runs with feedback and SST updates successful over Brazilian domain with inner and outer nest starting at same time - SAN 09/01/13 !!!

References