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Configuring & running the TIEGCM requires a few large static data files. All of these are available from the latest version of tiegcm_data from the TIEGCM download page. Specifically, CMIT requires a few NetCDF files:

  1. One Startup history file
    • Technically, this can be any TIEGCM history file. In practice, we recommend one of the default startup files from the tiegcm_data tarball.
  2. Two GSWM input files. Make It So will prompt you to enter the full path to the following GSWM files:
  3. One GPI file (optional; see below). Typically this file is here:

GPI File

As documented on the TIEGCM User Guide, the TIEGCM requires several parameters that can vary with time:

These parameters can be selected automatically by reading from the GPI_NCFILE with POTENTIAL_MODEL='HEELIS' (the only potential model we have tested with CMIT). TIEGCM can be run with constant values for these parameters or run off the varying data in the GPI file.

By default, CMIT derives values for KP,POWER,CTPOTEN, F107 and F107a from this GPI file. If you'd like to fix only F10.7 (but not KP), there are two ways to configure Make It So.

Running MakeItSo interactively

Constant F10.7 is an "expert" parameter. Run "makeItSo.config --expert". Once you get to the TIEGCM settings, you will be prompted something like:

Required "POTENTIAL" variables (? for help):
        GPI_NCFILE ( $TGCMDATA/ ):
        Enable "KP"? ( n ):
        Enable "POWER"? ( n ):
        Enable "CTPOTEN"? ( n ):
        Enable "F107"? ( n ): y
        F107 ( 100.0 ):
        Enable "F107A"? ( n ): y
        F107A ( 100.0 ):

Notice that by default, the GPI file is enabled, but KP, POWER, CTPOTEN, F107, F107A are disabled. type "y" or "yes" to enable F107. Then set the value you wish to use. Note: If you fix both KP and F107, you should probably disalbe "GPI_NCFILE" (press "CTRL+C" when prompted for GPI_NCFILE).

Editing a MakeItSo.config file

Open a MakeItSo.config file in a text editor. Look for the "TIEGCM" parameters and add F107 and F107A to the "POTENTIAL" parameter type. This will enable these variables & use the constants you specify:

       - F107: 100.0
       - F107A: 100.0

If you fix all the related variables (KP,POWER,CTPOTEN,F107,F107A), you need to disable "GPI_NCFILE":

      - GPI_NCFILE:
          status: disabled
          value: $TGCMDATA/
      - KP: 4.0
      - POWER: 6.0
      - CTPOTEN: 20.0
      - F107: 100.0
      - F107A: 100.0


MakeItSo doesn't do any error checking on the relationship between GPI_NCFILE and KP,POWER,CTPOTEN,F107,F107A. If you enable every one of these variables, the TIEGCM may do unpredictable things or fail entirely.

Configuring TIEGCM & CMIT with MakeItSo


LTR v2.1.3 (and older) require a few manual edits to a TIEGCM input file before running Make It So. This was fixed in LTR version 2.1.4 (refs issues #168 & #180)

First, you need to select the appropriate startup history file. This is done by two measures:

  1. Date: What day of the year corresponds to 20 days prior to the beginning of your run interval? This NASA Day of Year table may be helpful. You should choose the startup file corresponding closest to this day:
    • Day 80: Spring Equinox (eqnx)
    • Day 172: June solstice (jsol)
    • Day 355: December solstice (dsol)
  2. Solar conditions: What value of F10.7 cm flux are you using? Select a startup file based on solar wind conditions:
    • F10.7 = 70: Solar Min (smin)
    • F10.7 = 150: Solar Medium (smed)
    • F10.7 = 250: Solar Max (smax)

The TIEGCM Data download ships with startup histories for each of these solar wind conditions:


You now need to edit the first TIEGCM input file (typically tiegcm1.9-001.inp or tiegcm1.9-002.inp) generated by Make It So. Change the following:

  • SOURCE should point to the correct TGCM.tiegcm1.93.pcntr_*.nc file
  • SOURCE_START needs to be set to one of the following:
    • 80,0,0 for Spring equniox (eqnx)
    • 172,0,0 for June solstice (jsol)
    • 355,0,0 for December solstice (dsol)
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