The progress of a POP simulation is recorded in a 'log file' that is either written to standard output (stdout) or redirected to an optional log file. A new log file is created each time the model is started. Values of the model version number, release date, date and time of the run, input namelist parameters, and initial or restart conditions are documented at the beginning of each log file. After the introductory information, the log file will contain output from model timers and all the scalar diagnostics.
There are three types of scalar diagnostics available. Global diagnostics compute a variety of globally-averaged values of tracers, kinetic energy and several tendencies for checking balances. CFL diagnostics compute the Courant numbers for advection and diffusion terms. Transport diagnostics compute mass, heat and salt transports through various regions defined in an input file.
These diagnostics are chosen by setting the frequency freq_opt at which each diagnostic is computed. If diagnostics are chosen, the diagnostics are written both to the log file (or stdout) and to a separate diagnostics output file. Monitoring this output as the model runs is a useful way of making sure the model is behaving reasonably. For example, the Courant numbers reported in the CFL diagnostics should remain small and various tendencies reported in the global diagnostics should remain balanced.
In addition to printing these diagnostics to a log file, the diagnostics are printed to other output files in a format more suitable for various graphics programs. The output files are ASCII files with each line containing tday (decimal time in days for the entire simulation), the value of the diagnostic and a name for the diagnostic. The name of these output files can be changed using the variables diag_outfile, diag_transport_outfile.
| &diagnostics_nml | LANL default | CESM1 dipole-grid default | CESM1 tripole-grid default | Valid values | generation of model diagnostics |
| diag_global_freq_opt | 'never' | 'nmonth' 'nstep' if CESM1 INFO_DEBUG mode |
'nday' | 'never', 'nstep', 'nyear', 'nmonth', 'nday', 'nhour', 'nsecond' | units of time for 'diag_global_freq' |
| diag_global_freq | 100000 | 1 | 1 | integer > 0 | how often (in above units) to compute and print global diagnostics |
| diag_cfl_freq_opt | 'never' | 'nmonth' 'nstep' if CESM1 INFO_DEBUG mode |
'nday' | 'never', 'nstep', 'nyear', 'nmonth', 'nday', 'nhour', 'nsecond' | units of time for 'diag_cfl_freq' |
| diag_cfl_freq | 100000 | 1 | 1 | how often (in above units) to compute and print CFL stability diagnostics | |
| diag_transp_freq_opt | 'never' | 'nmonth' 'nstep' if CESM1 INFO_DEBUG mode |
'nday' | 'never', 'nstep', 'nyear', 'nmonth', 'nday', 'nhour', 'nsecond' | units of time for 'diag_transp_freq' |
| diag_transp_freq | 100000 | 1 | 1 | how often (in above units) to compute and print transport diagnostics | |
| diag_transport_file | 'sample_transport_file' | auto-filled by CESM1 scripts | auto-filled by CESM1 scripts | string ≤ 256 | input filename (with path) describing requested transports |
| diag_outfile | 'pop_diag' | auto-filled by CESM1 scripts (*pop.dd.*) | auto-filled by CESM1 scripts (*pop.dd.*) | string ≤ 256 | file to which global and cfl diagnostics are to be written |
| diag_transport_outfile | 'pop_transp' | auto-filled by CESM1 scripts (*pop.dt.*) | auto-filled by CESM1 scripts (*pop.dt.*) | string ≤ 256 | file to which transport diagnostics are to be written |
| diag_all_levels | .false. | .false. | .false. | .true.,false. | if .true., tracer mean diagnostics at all vertical levels are output |
| cfl_all_levels | .false. | .false. | .false. | .true.,false. | if .true., cfl diagnostics at all vertical levels are output |
| ldiag_velocity | N/A | .true. | .false. | .true.,.false. | if .true., velocity diagnostics are output |
| diag_velocity_outfile | N/A | auto-filled by CESM1 scripts (*pop.dv.*) | auto-filled by CESM1 scripts (*pop.dv.*) | string ≤ 256 | file to which velocity diagnostics are to be written |
| / |
| &budget_diagnostics_nml | CESM1 dipole-grid default | CESM1 tripole-grid default | Valid values | generation of tracer budget diagnostics |
| ldiag_global_tracer_budgets | .false. | .true. | .true.,.false. | if .true., compute model budget diagnostics |
| / |
| &bsf_diagnostic_nml | CESM1 dipole-grid default | CESM1 tripole-grid default | Valid values | generation of barotropic stream function diagnostics |
| ldiag_bsf | .false. | .true. | .true.,.false. | if .true., compute barotropic stream function diagnostics |
| / |