CAM3.1 Stand-alone - Unsupported

TraCE CAM3.1 Stand-alone with multi-year climate forcing  - expert users only

This page describes a step-by-step process for running the 22,000 year TraCE simulation using the stand-alone version of CAM3.1.  This describes an AMIP-stype forcing where CAM is forced by a multi-year climate forced by a 50 year SSTs (as opposed to a 12 month repeating climatology).  SST forcing is estimated using TS and ICE_FRAC extracted from atmosphere history files.




  1. Download the TraCE Roadmap.pdf for reference.
  2. Copy original source code to your directory:    

    • cp -pR /glade/proj2/cgd/ccr/paleo/TRACE/SA-T31 to myPath

  3. Choose the TraCE time slice or period of interest (POI) you want to use (e.g., 14.5ka). 
    1. Identifiy the case name (CASEID) that corresponds to the time period you have chosen.  In this case, the TraCE Roadmap shows that there are two TraCE timeslices that bookend the years 14.5:  b30.14_9kaDVT and b30.14_35kaDVT.  You would use the b30.14_9kaDVT simulation because as the model runs forward in time, it counts down toward the present day through year 14.5. 
    2. Identify the years within this time slice that correlate to your POI.  e.g., 14.5ka = 14.9yr0 + 400y = 14.9yr400 = 14.5ka
  4. If you can't find the required restart, initial, surface-dataset or history files, notify NCAR ( with an email that identifies your caseid (b30.14_9kaDVT), and start year.
  5. Create a 51y SST and sea ice timeseries using TS and ICEFRAC from the atm history files as proxies for SST and sea ice.
    1. machine:  mirage0
    2. create a working directory:
      1. If you are on mirage0, use this path:  /glade/user/<USER>/TRACE/b30.14_9kaDVT
    3. srcDir:  /SA-T31/source/
    4. script: 
    5. infile: (atm history files)
    6. outfile: b30.14_9kaDVT.450-500_SST.<DATE>.nc
  6. Create the CAM initial condition file (cami).  Note that the forcing file will have 50yrs of 12 month records, plus the previous December, for a total of ((nyrs*12) + 1) records
    1. machine:  mirage0
    2. srcDir:  /SA-T31/source/
    3. script: mk_sst_cam_forcing_file.ncl
    4. input:  b30.14_9kaDVT_ic_48x96_climo.531-550.<DATE>.nc
    5. output:  sst_ic_b30.14_9kaDVT.053112-055012.<DATE>.nc
  7. Extract the greenhouse gases for your time period
    1. machine:  bluefire
    2. srcDir:  /SA-T31/cam_runs/scripts
    3. script:  calc_ghg.ncl
    4. modify script for your time period and run script. 
    5. output file:  ghg_14.37kaBP.txt
  8. Set up and run the production simulation.
    1. machine:  bluefire
    2. srcDir:  /SA-T31/cam_runs/scripts/
    3. script:  bld-production.csh
    4. modify the build script to point to your newly created forcing files.
    5. build your production case:  ./bld-production.csh
    6. run your production case:  bsub < run-cam.csh
  9. Archive history files using an automated script: 
    1. source:   ~nanr/tools/
    2. modify script for your CASEID.
    3. copy into your run directory and manually start the script:
      1. usage:  ./
    4. Note:  The script first checks for the history files on the HPSS, then writes all history/rest/init files to the HPSS, then moves the local copy to your local /ptmp/user/archive/CASEID directory.  You must delete them from there once you are satisfied the archiver is working properly to store your files on the HPSS.
  10. Alternate:  Archive history files to HPSS (manually):
    1. cd /ptmp/<USER>/<my-run-path>/rundir/
    2. log onto the HPSS (this will put you in your home directory: e.g., /home/nanr/):  hsi -P   
    3. create a new case directory:  (e.g., mkdir cam_b30.14_37kaDVT_T85)
    4. cd cam_b30.14_37kaDVT_T85/
    5. create land and atm subdirectories:  mkdir [lnd,atm]/[hist,rest,init].  e.g.:
      1. mkdir lnd
      2. mkdir lnd/hist
      3. mkdir lnd/rest
      4. mkdir lnd/init
    6. cd to those directories and put your files there: e.g.:
      1. cd lnd/rest
      2. put


  • Customize the "user modification" section for each source code for your time period (POI) and the filenames of the new files you create.  Look for CASEID or <CASEID> or <POI> for places you need to modify the code.  Most steps of the code will automatically look for the input files and place the output files in directories relative to the source directory.
  • POI = "Period of Interest"
  • CASEID = TraCE name (e.g., b30.14_9kaDVT)
  • perl script usage:  ./
  • ncl script usage:  ncl mk_sst_cami_forcing.ncl
  • Download a copy of Feng's thesis here.

ORNL Notes for retrieving restart files:

hsi:   cd /home/fenghe/CCSM/b30.14_9kaDVT/restart.tars
hsi:  [/home/fenghe/CCSM/b30.14_9kaDVT/restart.tars]: get b30.14_9kaDVT.ccsm.r.0401-01-01-00000.080724-122437.tar


Original source code:   /glade/proj2/cgd/ccr/paleo/TRACE/

  • cp -pR SA-T31 to myPath