PROGRAM roms_to_dart

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version information for this file:
$Id: roms_to_dart.html 9425 2016-01-06 20:20:44Z thoar $

NAMELIST / MODULES / FILES / REFERENCES / ERRORS / PLANS / TERMS OF USE

Overview

roms_to_dart is the program that reads metadata from a ROMS grid definition file (usually linked to roms_grid.nc), the model state from a ROMS restart file (usually linked to roms_restart.nc) and creates a DART output/restart file (e.g. perfect_ics, filter_ics).

The list of variables used to create the DART state vector are specified in the input.nml file.

Conditions required for successful execution of roms_to_dart:

Since this program is called repeatedly for every ensemble member, we have found it convenient to link the ROMS restart and grid files to the default filenames roms_restart.nc, roms_history.nc, respectively. The default DART output filename is dart_ics - this may be moved or linked as necessary. The default filenames may be changed via the namelist.

Credits

roms_to_dart was originally written by Peng Xiu of the University of Maine and was subsequently modified by the DART team.

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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.

&roms_to_dart_nml
   roms_to_dart_output_file  = 'dart.ics'
   perturb_state             = .false.
   print_data_ranges         = .true.
   /

&model_nml
   analysis_time                = '2011-01-03 00:00:00'
   output_state_vector          = .false.
   assimilation_period_days     = 5
   assimilation_period_seconds  = 0
   model_perturbation_amplitude = 0.2
   hc                           = 250.0
   model_restart_filename       = 'roms_restart.nc'
   grid_definition_filename     = 'roms_grid.nc'
   vert_localization_coord      = 3
   debug     = 1
   variables = 'temp',   'KIND_TEMPERATURE',
               'salt',   'KIND_SALINITY',
               'u',      'KIND_U_CURRENT_COMPONENT',
               'v',      'KIND_V_CURRENT_COMPONENT',
               'zeta',   'KIND_SEA_SURFACE_HEIGHT'
  /



The roms_to_dart namelist items:

Item Type Description
roms_to_dart_output_file character(len=256) The name of the DART file containing the model state derived from the ROMS restart file.
perturb_state logical switch to add perturbations to the input ROMS state. The perturbations come from the model_mod.f90 pert_model_state() routine.
print_data_ranges logical switch to print a summary of the min/max of each variable that will be part of the DART vector.


The &model_nml namelist here is a subset of the full namelist. Only the values used by the converter are listed here. The full description of the model_nml namelist is documented in the ROMS model_mod documentation, but the most important variable for roms_to_dart is repeated here.

Item Type Description
analysis_time character(len=20) At present, this is a way to specify the valid time of the LAST timestep in the ROMS restart file. When the restart file has enough metadata to determine this, the analysis_time should be removed. An alternate way to override the file-derived start time is to use the input.nml &filter_nml: init_time_days, init_time_seconds mechanism.
variables character(len=NF90_MAX_NAME) ::
dimension(160)
The list of variable names in the ROMS restart file to use to create the DART state vector and their corresponding DART kind.

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MODULES USED

assim_model_mod
location_mod
model_mod
null_mpi_utilities_mod
obs_kind_mod
random_seq_mod
time_manager_mod
types_mod
utilities_mod
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FILES Read

FILES Written

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REFERENCES

none

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ERROR CODES and CONDITIONS

none - all error messages come from modules that have their own documentation.

KNOWN BUGS

none

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FUTURE PLANS

  1. Remove the hardcoded analysis_time from the code.

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Terms of Use

DART software - Copyright 2004 - 2013 UCAR.
This open source software is provided by UCAR, "as is",
without charge, subject to all terms of use at
http://www.image.ucar.edu/DAReS/DART/DART_download

Contact: DART core group
Revision: $Revision: 9425 $
Source: $URL: https://svn-dares-dart.cgd.ucar.edu/DART/releases/classic/models/ROMS/roms_to_dart.html $
Change Date: $Date: 2016-01-06 13:20:44 -0700 (Wed, 06 Jan 2016) $
Change history:  try "svn log" or "svn diff"