Scheduled Downtime
On Tuesday 24 October 2023 @ 5pm MT the forums will be in read only mode in preparation for the downtime. On Wednesday 25 October 2023 @ 5am MT, this website will be down for maintenance and expected to return online later in the morning.
Normal Operations
The forums are back online with normal operations. If you notice any issues or errors related to the forums, please reach out to help@ucar.edu

Control the frequency of the initial condition output frequency

J

junjie_liu@jpl_nasa_gov

New Member
Hi,

I am trying to change the CAM initial condition output frequency in CESM1.2. I set the total model run length 12 hours, and I want to write out the CAM5 initial condition every 6 hours. So I set "inithist=6-HOURLY" in the user defined namelist. In the "atm_in" file, there is "inithist = '6-HOURLY'". However, the model only outputs the initial condition file (*.cam5.i.*.nc) file at the end of the run.

How should I change the initial condition output frequency in CESM1.2?

Thanks,

Junjie
 
E

eaton

CSEG and Liaisons
Are you trying to do this in a restart run?  If so that setting will be ignored.  You need to be doing an initial or branch run to have the namelist affect the history output. 
 
J

junjie_liu@jpl_nasa_gov

New Member
Hi, Eaton,Thanks for your reply. I am trying to do it in a hybrid run. What namelist variable controls the initial condition output frequency in hybrid run? Thanks, Junjie
 
E

eaton

CSEG and Liaisons
I think for a hybrid run the inithist variable should be functional.  Check that you are modifying the namelist correctly.  If you are directly modifying the atm_in file then perhaps your change is being overwritten?  User customization of the namelist should be done via the user_nl_cam file. 
 
J

junjie_liu@jpl_nasa_gov

New Member
Thanks for your comments. But it still does not work for me. I even changed the runtype to "startup". I run 12 hours, and set inithist equal to "6-HOURLY". In the result, it only write out the initial condition file at the end of 12 hour run.In "drv_in", the variable "start_type" is equal to "startup", and in atm_in, the variable "inithist" is equal to "6-HOURLY". Do you have any clue why this happens? and how I can make it work?Thanks, Junjie
 
E

eaton

CSEG and Liaisons
Look in CAM's log file.  It contains a listing of all fields in the master field list as well as all the fields in each active history file.  In addition, for each history file the write frequency will be given.  For example, the following shows output for the default frequency of writing the initial file:
 
Code: 
FLDLST: History file           12  contains           29  fields
  Write frequency:                 YEARLY   (INITIAL CONDITIONS)
  Filename specifier:              %c.cam.i.%y-%m-%d-%s.nc
  Output precision:                double
  Number of time samples per file:            1
  Included fields are:
    1 CLDICE&IC                        kg/kg              30 I  Grid box averaged cloud ice amount                                                                                                                                                                                                                              
    2 CLDLIQ&IC                        kg/kg              30 I  Grid box averaged cloud liquid amount                                                                                                                                                                                                                           
.....
If you don't see the value 6-HOURLY in the output log then the problem is in how the namelist is being customized.
 
J

junjie_liu@jpl_nasa_gov

New Member
I just checked the log file. The log file does has "6-HOURLY" information. The following is from the log file:FLDLST: History file            8  contains           37  fields  Write frequency:                 6-HOURLY (INITIAL CONDITIONS)  Filename specifier:              %c.cam_0004.i.%y-%m-%d-%s.nc  Output precision:                double  Number of time samples per file:            1  Included fields are:    1 CLDICE&IC                        kg/kg              30 I  Grid box averaged cloud ice amount                                                                                        2 CLDLIQ&IC                        kg/kg              30 I  Grid box averaged cloud liquid amount                                                                                     3 DMS&IC                           kg/kg              30 I  DMS                                                                                                                       4 H2O2&IC                          kg/kg              30 I  H2O2                                                                                                                      5 H2SO4&IC                         kg/kg              30 I  H2SO4                                                                                                                     6 ICEFRAC&IC                       fraction            1 I  Fraction of sfc area covered by sea-ice                                                                                I attached the log file. It is weird that I saw the 6-hour initial file writing in the log file, but I could not find the files in either history folder or rest folder. Thanks for your help, JunjieThanks, Junjie
 
M

mdfowler@uci_edu

New Member
Hi Junjie, I was wondering if you recall your solution to this problem, as I'm having a similar one now. My inic files aren't in the archive or run folders, only the last day of the simulation is available.  Cheers,Meg
 
You must log in or register to reply here.
Top