PROGRAM create_ocean_obs

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 MODULE 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 program 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