How to run off-line meteorology for CAM5

[chen63@illinois_edu]

I am running cesm1.0.4 with compset FC5. Could anyone please tell me how I can run off-line meteorology in this model version? Thanks!

 

[fvitt]

 Add " -offline_dyn -nlev 56" to CAM_CONFIG_OPTS in env_build.xml Then in user_nl_cam point to appropriate meteorology, topography, and IC input files.  For example:  ncdata        = '/glade/p/cesm/cseg//inputdata/atm/cam/inic/fv/camchem_ic_2008-01-01_1.9x2.5_L56_c110118.nc' bnd_topo  = '/glade/p/cesm/cseg/inputdata/atm/cam/met/USGS-gtopo30_1.9x2.5_phys_geos5_c100929.nc' met_data_file        = '2008/GEOS5.1_19x2_2008-JAN_c110728.nc'
 met_data_path        = '/glade/p/cesm/cseg//inputdata/atm/cam/met/GEOS5'
 met_filenames_list        = '/glade/p/cesm/cseg//inputdata/atm/cam/met/GEOS5_filenames_list_c120516.txt'

 

 

[chen63@illinois_edu]

Thanks a lot!

 

[chen63@illinois_edu]

I have two more questions:(1) Should I add  " -offline_dyn -nlev 56" to CAM_CONFIG_OPTS in env_build.xml or env_conf.xml?(2) I have several met_data files, how should I list them in met_data_file? Or do I just need to list them in met_filenames_list?Thanks!

 

[tilmes]

1) in this model version, you need to add it to env_conf.xml2) you list them in the met_filenames_list file.

 

[tilmes]

In addition to the changes described by Francis, you need to change the env_run.xml:and make sure that the following in env_build.xml is set:

 

[fvitt]

For CESM1.0.4, key to getting CAM build-namelist work is setting CAM_CONFIG_OPTS in env_conf.xml
to set ncdata to an appropriate IC file.

Following is a summary of what needs to be done to run compset FC5 compset in a specified dynamics mode.

In  env_conf.xml:

 set CAM_CONFIG_OPTS to "-phys cam5 -offline_dyn -nlev 56"
 set RUN_STARTDATE to "2008-01-01"
 set CAM_NAMELIST_OPTS to "ncdata='$DIN_LOC_ROOT/atm/cam/inic/fv/camchem_ic_2008-01-01_1.9x2.5_L56_c110118.nc'"

In  env_build.xml:

 set USE_ESMF_LIB to "TRUE"

In  env_run.xml:

 set  CALENDAR to "GREGORIAN"

Create a file named user_nl_cam which contains:
 &cam_inparm
 bnd_topo  = '/nobackup/fvitt/ccsmdata/inputdata/atm/cam/met/USGS-gtopo30_1.9x2.5_phys_geos5_c100929.nc'
 met_data_file = '2008/GEOS5.1_19x2_2008-JAN_c110728.nc'
 met_data_path = '/nobackup/fvitt/ccsmdata/inputdata/atm/cam/met/GEOS5'
 met_filenames_list = '/nobackup/fvitt/ccsmdata/inputdata/atm/cam/met/GEOS5_filenames_list_c120516.txt'
/

You will need to use the correct path to the inputdata for you system.

 

[chen63@illinois_edu]

Thanks for your reply! A following question about question 2, should I list the first file in met_data_file?

 

[chen63@illinois_edu]

Thank you very much for the detailed and summarized answer on how running offline meteorology. Could you please also help me with these follow-up questions:(1) About the IC file, If I want to use the GEOS5 generated meteorology, I need to have an IC file with 56 levels. The current IC file with 56 levels in the CESM inputdata directory is for camchem as listed in your instructions. Since F_2000_CAM5 (FC5) is running MAM3 chemistry instead of CAM-chem, should I create my own IC file if running offline meteorology for F_2000_CAM5? Is there any way that I can create an IC file with 56 levels from other FC5 runs? (2) You suggested change ncdata in env_conf.xml, can I change ncdata in user_nl_cam instead of in env_conf.xml? (3) If I have several met data files, I should list them in the met_filenames_list. Should I list the first one in met_data_file, or should I just leave met_data_file not specified?(4) Do I need to create my own compset in order to run offline meteorology? Can I just use the compset provided (i.e., F_2000_CAM5) and make the above changes as shown in your instruction?(5) I noticed that the default FC5 run is using a different bnd_topo file as the one for GEOS5. What's the difference between these topo files?(6) Besides GEOS5 generated meteorology, I am also interested in running ERA-interim met data with cesm1.0.4. Can we do this following the instructions above by just changing the file of the met data?Sorry about the messy questions. I am a beginner to running cesm, and found the forum is the best place to seek answers. Your help and advice are highly appreciated. 

 

[fvitt]

1) One option is to interpolate an existing CAM5 IC file to the 56 levels of GEOS met data.  Another option is to use the CAM-Chem IC file as I did and run a few years to spin up the aerosol tracers.  CAM generates yearly IC files by default.  The IC files generated at the end of this spin up run can be used.

2) The problem with specifying ncdata only in user_nl_cam is that CAM's build-namelist utility will complain that there is no default IC file for the 56-level configuration and exit with an error.  Setting ncdata in env_conf.xml via CAM_NAMELIST_OPTS gives the user the ability to specify an IC file.

3) The met_filenames_list sequentially lists the met files you would like the model to run through. The namelist variable met_data_file specifies the first file that is used (met_data_file is required).

4) Creating your own compset is not required to run with specified dynamics.  However, this may be a good alternative to all the required changes need to the case files (as I outlined previously).

5) It is important to use a bnd_topo file which has PHIS that matches the PHIS in the met data.

6) If you would like to use a different set of met data (such as ERA-interim) you will need to create an appropriate bnd_topo file (PHIS from met data) and an IC which has levels that match the meteorology data.

 

 

[chen63@illinois_edu]

Thanks! One more question is that: do we need to set SST via certain namelist variables to run offline meteorology? I didn't see SST listed as a variable in the GEOS5 met file. Should we use SST in order to calculate radiation? Thanks!

 

[fvitt]

We use default SST (sea surface temperature) inputs when we run in specified dynamics mode.  In specified dynamics mode the SST inputs have no effect on the climate since U,V and T are force to the offline meteorology.

 

[chen63@illinois_edu]

Thanks for your kindly reply. One more question about using ERA-interim data as offline meteorology, is there any place where I can found the ERA-interim data as the right input for CESM, I mean, with the same vertical layers and grid resolution (1.9 * 2.5)? 

 

[po-lun_ma@pnnl_gov]

We have the ERA-Interim data to drive the offline CAM5 for our friends/collaborators for research purpose but it's not released yet. Please contact me if you want to use the data.Po-Lun Ma

 

[snowyang1988@gmail_com]

Hello  Professor Ma,I want use the ERA-Interim data to drive the SD-WACCM. Can I contact you directly in your PNNL web?Jeff

 

[po-lun_ma@pnnl_gov]

Sure. Feel free to email me directly. Po-Lun

 

[littleho_song@yahoo_com]

Can anyone provide an update on this? 1.2 doesnt have env_conf file

 

[fvitt]

For CESM1.2 CAM_CONFIG_OPTS is set in env_build.xml while RUN_STARTDATE and CAM_NAMELIST_OPTS are set in env_run.xml.Also for CESM1.2 the ESMF lib is not need to use GREGORIAN calendar.

 

[yongjia_song@gmail_com]

Hello tilmes, Could you please let me where and how to tuning of q-fluxes? I got the problem to run cesm1.2 with merra met-data forcing, which show me 'Impossible case2 in instratus_condensate'. Thanks a lot!

 

[tilmes]

Hi Yongjia,
met_qflux_factor can be used to tune the q-fluxes. For CAM5Chem, you neeed to add the following to your namelist.&metdata_nlmet_qflx_factor                = 0.84

 Simone