PROGRAM cam_to_dart

Attention

cam-old works with versions of DART before Manhattan (9.x.x) and has yet to be updated. If you are interested in using cam-old with more recent versions of DART, contact DAReS staff to assess the feasibility of an update. Until that time, you should consider this documentation as out-of-date.

Overview

cam_to_dart is the program that reads a CAM restart file (usually caminput.nc) and creates a single DART output/restart file (e.g. perfect_ics, filter_ics, ... ). If you have multiple input files, you will need to rename the output files as you create them.
The list of variables extracted from the CAM netCDF file and conveyed to DART is controlled by the set of input.nml &model_nml:state_names_* variables. The date and datesec variables in the CAM netcdf file are used to specify the valid time of the state vector. The time may be changed with the PROGRAM restart_file_tool if desired.
Some CAM restart files are from climatological runs and have a valid time that predates the use of the Gregorian calendar. In such instances, the year component of the original date is changed to be a valid Gregorian year (by adding 1601). A warning is issued to the screen and to the logfile. Please use the PROGRAM restart_file_tool to change this time.
Conditions required for successful execution of cam_to_dart:

  • a valid input.nml namelist file for DART

  • a CAM ‘phis’ netCDF file [default: cam_phis.nc]

  • a CAM restart file [default: caminput.nc].

Since this program is called repeatedly for every ensemble member, we have found it convenient to link the CAM restart files to the default input filename (caminput.nc). The default DART output filename is dart_ics - this may be moved or linked as necessary.

Namelist

This namelist is read from the file input.nml. Namelists start with an ampersand ‘&’ and terminate with a slash ‘/’. Character strings that contain a ‘/’ must be enclosed in quotes to prevent them from prematurely terminating the namelist.

&cam_to_dart_nml
   cam_to_dart_input_file  = 'caminput.nc',
   cam_to_dart_output_file = 'dart_ics',
   /

Item

Type

Description

cam_to_dart_input_file

character(len=128)

The name of the DART file containing the CAM state.

cam_to_dart_output_file

character(len=128)

The name of the DART file containing the model state derived from the CAM restart file.

Modules used

assim_model_mod.f90
types_mod.f90
threed_sphere/location_mod.f90
model_mod.f90
null_mpi_utilities_mod.f90
obs_kind_mod.f90
random_seq_mod.f90
time_manager_mod.f90
utilities_mod.f90

Files read

  • DART namelist file; input.nml

  • CAM restart file; caminput.nc

  • CAM “phis” file specified in &model_nml::cam_phis (normally cam_phis.nc)

Files written

  • DART initial conditions/restart file; e.g. dart_ics

References

none