## page was renamed from add_noonpos
=== Program add_noonpos ===

The positions at noon or a synoptical time are calculated by ''traj'' and added to the NetCDF file.

==== Configuration file ====

The options for the execution of add_noonpos can be set in the configuration file '''add_noonpos.inp''':
{{{
1)  mls_050115.nc                 ! input file
2)  mls_050115_noonpos_new.nc     ! output file
3)  1           ! interval between synoptical times in days (1->NOONPOS, >1->SYNPOS)
4)  n           ! use ZETA for traj (y->ZETA,n->THETA)
5)  press       ! shortname of level (NONE for time series)
6)  LAT         ! shortname of latitude
7)  LON         ! shortname of longitude 
8)  THETA       ! shortname of theta
9)  ZETA        ! shortname of zeta 
10) xxx         ! shortname of temperature
11) xxx         ! shortname of pressure
12) /private/icg122/ecmwf_isen_0405_new    ! directory with isentropic files
13) ECN        !  prefix of isentopic files
14) /home/icg1/icg112/clams/traj/traj      ! trajectory program
15) THETA_DOT  ! short name of variable containing THETA-DOT information
16) 6          ! data frequency in hours (1,2,3,4,6,8,12,24) 
17) n          ! y/n -> 3d(with theta_dot)/2d(without theta_dot) run 
18) 1800       ! first timestep in seconds
19) 300        ! second timestep in seconds
20) n          ! y/n: delete all files created by traj (pos-files,traj-files,traj.inp,traj.out)
21) outdir     ! directory with temporary files created by traj (pos-files,traj-files)
}}}

Remarks:
 1. Name of input NetCDF file 
 1. Name of output NetCDF file; it is a copy from input file with the positions at noon or synoptical time added
 1. Interval between synoptical times. If "1" is specified, the positions at noon of each day are written to `NOONLAT,NOONLON,NOONTHETA/NOONZETA` and `NOONTIME`. If n>1 is specified, the positions in the middle of each interval are written to `SYNLAT,SYNLON,SYNTHETA/SYNZETA` and `SYNTIME`. 
 1. Use theta or zeta for trajectory calculation 
 1. Shortname of level dimension in input file. If there is no level dimension in input file, specify "NONE".
 1. Shortname of variable containing latitudes.
 1. Shortname of variable containing longitudes.
 1. Shortname of variable containing theta levels. If "n" is specified in line 4, the input file must contain theta information or temperature and pressure.
 1. Shortname of variable containing zeta levels.  If "y" is specified in line 4, the input file must contain zeta information or temperature and pressure
 1. Shortname of variable containing temperatures. The temperatures are only read, if there is no variable with theta/zeta levels in input file.
 1. Shortname of variable containing pressure levels. The pressure levels are only read, if there is no variable with theta/zeta levels in input file.
 1. Directory with isentropic files (used by trajectory program)
 1. Prefix of isentropic files (3 characters)
 1. Executable trajectory program <<BR>>
 1. -19. Configuration for trajectory program
 1. If "y" is specified in line 20, all files created by traj (pos-files and traj-files) are deleted. This specification is optional, the default is "n".
 1. The pos-files and traj-files created by traj are written to the directory specified in line 21. If no directory is specified, the files are written to the current working directory.


==== Input Files ====

Dimensions:
 * `time` 
 * optional a level dimension (e.g. `press`, `theta`, `zeta`, `alt`, `hgt`); 
 The name of this dimension is specified in line 5  of add_noonpos.inp, specify "NONE" if there is no level dimension

Coordinate variables:
 * `time(time)` in julian seconds

Variables:
 * latitude (e.g. `LAT`,`latitude`), the name is specified in line 6 of add_noonpos.inp.<<BR>> 
 Possible dimensions of latitude are `(time)`, `(level,time)` or `(time,level)`
 * longitude (e.g. `LON`,`longitude`), the name is specified in line 7 of add_noonpos.inp.<<BR>>
 Possible dimensions of longitude are `(time)`, `(level,time)` or `(time,level)`
 * theta (e.g. `theta`,`THETA`,`THETA_UKMO`), the name is specified in line 8 of add_noonpos.inp.<<BR>>
 Possible dimensions of theta are `(theta), (time), (time,level), (level,time)`
 * zeta (e.g. `zeta`,`ZETA`), the name is specified in line 9 of add_noonpos.inp. The input file must contain the variable zeta, if "y" is specified in line 4.<<BR>>
 Possible dimensions of zeta are `(time), (time,level), (level,time)`