All parameters pertaining to one run are stored in a file called 'runme'. Since there are several hundreds parameters one should start with a template. Many parameters probably will never need changing. Often a 'default' can be used. The defaults are defined in $OPENGGCMDIR/include/input.defines. The most important ones are these:
- TARGET points to a file in $OPENGGCMDIR/conf/target/ that defines the characteristics (compilers, batch system etc.) of the target machine. Some need TARGETUSER and TARGETHOST to be set.
- RUNTIME time limit for batch system
- NPX/NPY/NPZ partitioning of the MHD grid into NPX*NPY*NPZ boxes. The code will require NPX*NPY*NPZ+NN cores, where NN depends on what other modules are loaded, but at least NN>=2.
- NX/NY/NZ gridpoints in each dimensions. Obviously NX/NPX etc. need to be integer.
- DY0/DZ0 minimum grid size in y/z direction. No free lunch. Small values shrink the size of the high res region.
- XX1...ZZ2 box dimensions.
- DXFUNC Fortran expression for dx(x). Will be scaled for NX and XX1/XX2.
- MAGDIFFU etc sets imposed resistivity model and parameters.
- OUTTIMExxx when to write 2d, 3d, and io output. Either a list of times (seconds since start) or a negative number for cadence. Lists are ':' separated.
- OUTPLANExyz write 2d cut planes at given locations produces p[x|y|z]_offset files. Nothing written if plane is outside box.
- OUTSUB3D write only smaller box for 3d
- ETAJOUT include staggered B/E in output for particle tracing.
- ORBIT... write stuff along orbits at high cadence
- CHECKPOINT/RESTART definitely does not work with sub models CTIM, RCM etc
- RRMIN minimum allowed density
- SPEEDLIMIT minimum allowed speed for stability
- DTMIN kill run when time step control goes below DTMIN, typical for instability/crash
- DIAGS selects between different output modules.
- OUTTIMExxx time in seconds when to output. ':' separated list. Negative values are a cadence.
- OUTTIMEEX T1:T2:TT increase cadence by factor TT between T! and T2. All times in seconds since start.
- OUTPLANExyz output on cut planes. List of offsets (in RE MHD coords) given. Output only if plane is in box.
- OUTSUB3d smaller 3d box.
- STARTTIME/ENDTIME
The RCM domain is controlled by the following parameters. The RCM time of execution is primarily affected by feedback tracing. Reducing the forward tracing boundary can result in an incorrect representation of the open-closed boundary location.
The RCM only uses MHD data within the following bounds:
- RCM_XX1 sunward boundary of rcm domain
- RCM_XX2 anti-sunward boundary of rcm domain
- RCM_YY1 +- y boundary of rcm domain
- RCM_ZZ1 +- z boundary of rcm domain
Forward and feedback field line tracing are limited by these parameters:
- RCM_RMAX field line is considered open if farther than this
- RCM_MIN_B fieldlines with |B| < rcm_min_b considered to be open
- RCM_RFLMAX max allowed field line length
- RCM_MAX_BETA maximum allowed beta in equatorial plane
RCM feedback to MHD is further limited by these parameters:
- RCM_FEEDBACK_BND feedback only to this distance
- RCM_FB_MIN_B don't feedback on fieldlines where |B| < rcm_fb_min_b
Field line tracing magnetic field is defined by the following parameters:
- RCM_RMIN_DIP_MHD_BLEND lower boundary for dipole-mhd blend -- below this is only dipole (def=4.5)
- RCM_RMAX_DIP_MHD_BLEND upper boundary for dipole-mhd blend -- beyond this is only mhd (def=6.5)
