Skip to content

Latest commit

 

History

History
151 lines (123 loc) · 12.3 KB

create_ocean_obs.rst

File metadata and controls

151 lines (123 loc) · 12.3 KB
Raw

PROGRAM create_ocean_obs

Attention!

MITgcm_ocean works with versions of DART before Manhattan (9.x.x) and has yet to be updated. If you are interested in using MITgcm_ocean 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 Until that time, you should consider this documentation as out-of-date.

create_ocean_obs is responsible for converting an interim ASCII file of ocean observations into a DART observation sequence file. The interim ASCII file is a simple 'whitespace separated' table where each row is an observation and each column is specific information about the observation.

column number quantity description
1 longitude (in degrees) longitude of the observation
2 latitude (in degrees) latitude of the observation
3 depth (in meters) depth of the observation
4 observation value such as it is ...
5 vertical coordinate flag There is a pathological difference between a surface observation and an observation with a depth of zero. See location_mod:location_type for a full explanation. The short explanation is that surface == -1, and depth == 3
6 observation variance good luck here ...
7 Quality Control flag integer value passed through to DART. There is a namelist parameter for filter to ignore any observation with a QC value <= input_qc_threshold
8 obs_kind_name a character string that must match a string in :doc:`../../observations/forward_operators/obs_def_ocean_mod`
9 startDate_1 the year-month-date of the observation (YYYYMMDD format)
10 startDate_2 the hour-minute-second of the observation (HHMMSS format)

For example:

273.7500 21.3500 -2.5018 28.0441  3 0.0400  1  GLIDER_TEMPERATURE 19960101  10000
273.7500 21.4500 -2.5018 28.1524  3 0.0400  1  GLIDER_TEMPERATURE 19960101  10000
273.7500 21.5500 -2.5018 28.0808  3 0.0400  1  GLIDER_TEMPERATURE 19960101  10000
273.7500 21.6500 -2.5018 28.0143  3 0.0400  1  GLIDER_TEMPERATURE 19960101  10000
273.7500 21.7500 -2.5018 28.0242  3 0.0400  1  GLIDER_TEMPERATURE 19960101  10000
273.7500 21.8500 -2.5018 28.0160  3 0.0400  1  GLIDER_TEMPERATURE 19960101  10000
273.7500 21.9500 -2.5018 28.0077  3 0.0400  1  GLIDER_TEMPERATURE 19960101  10000
273.7500 22.0500 -2.5018 28.3399  3 0.0400  1  GLIDER_TEMPERATURE 19960101  10000
273.7500 22.1500 -2.5018 27.8852  3 0.0400  1  GLIDER_TEMPERATURE 19960101  10000
273.7500 22.2500 -2.5018 27.8145  3 0.0400  1  GLIDER_TEMPERATURE 19960101  10000
...

It is always possible to combine observation sequence files with the program :doc:`../../assimilation_code/programs/obs_sequence_tool/obs_sequence_tool`, so it was simply convenient to generate a separate file for each observation platform and type ('GLIDER' and 'TEMPERATURE'), however it is by no means required.

Modules used

Some of these modules use modules ... those modules and namelists are not discussed here. probably should be ...

types_mod
utilities_mod
dart_MITocean_mod
obs_sequence_mod

Namelist

This program has a namelist of its own, and some of the underlying modules require namelists. To avoid duplication and, possibly, some inconsistency in the documentation; only a list of the required namelists is provided - with a hyperlink to the full documentation for each namelist.

Namelist Primary Purpose
utilities_nml set the termination level and file name for the run-time log
obs_sequence_nml write binary or ASCII observation sequence files

We adhere to the F90 standard of starting a namelist with an ampersand '&' and terminating with a slash '/'. Consider yourself forewarned that filenames that contain a '/' must be enclosed in quotes to prevent them from prematurely terminating the namelist.

namelist /create_ocean_obs_nml/  year, month, day, &
         tot_days, max_num, fname, output_name, lon1, lon2, lat1, lat2

This namelist is read in a file called input.nml

Contents Type Description
year integer [default: 1996] The first year of interest.
month integer [default: 1] The first month of interest.
day integer [default: 1] The first day of interest.
tot_days integer [default: 31] Stop processing after this many days.
max_num integer [default: 800000] The maximum number of observations to read/write.
fname character(len=129) [default: 'raw_ocean_obs.txt'] The name of the interim ASCII file of observations.
output_name character(len=129) [default: 'raw_ocean_obs_seq.out'] The output file name.
lon1 real [default: 0.0] The leftmost longitude of interest.
lon2 real [default: 360.0] The rightmost longitude of interest.
lat1 real [default: -90.0] The most southern latitude of interest.
lat2 real [default: 90.0] The most northern latitude of interest.

Files

  • input namelist file: input.nml
  • input data file: as listed by input.nml&create_ocean_obs_nml:fname
  • output data file: as listed by input.nml&create_ocean_obs_nml:output_name

References

  • none