2.3 Output files handling

2.3.1 File structure

  Output files are ARPEGE/ALADIN files.

• If you ask for a gaussian grid in output (CFPFMT='GAUSS') you will get a file ARPEGE.
• If you ask for a LAM grid (CFPFMT='LELAM') you will get a file ALADIN.
• If you ask for LAT X LON grids (CFPFMT='LALON') you will get files ALADIN with the only particularity that the output geometry is not projected.
• If you ask for the model geometry (CFPFMT='MODEL') you can get either spectral or gridpoint data.

Notice : to plot LAM or LAT X LON grids you can use the graphic procedure chagal.

2.3.2 File name

There is one post-processing file for each post-processing time step and each (sub-)domain.

      The output files are named : PF${CNMEXP}${CFPDOM}+nnnn, where :

PF

is a prefix

$CNMEXP

is the so-called "name of the experiment" (value : CNMEXP(1:4))

$CFPDOM

is the name of the output (sub-)domain (CFPDOM)

nnnn

is the time stamp.

Example : if you ask for post-processing at time 0, with CNMEXP='FPOS' and CFPDOM='ANYWHERE', then the output file will be named : PFFULLANYWHERE+0000

2.3.3 File content

To read a field in an output file, you have to specify through the subroutine FACILE the name of the field you wish to get.

  For a "surface" field, this name is the ARPEGE field name that has been defined in the namelist NAMFPC ; it is a string of 16 characters.

  For an upper air field, this name is also the ARPEGE field name that has been defined in the namelist NAMFPC (string of 12 characters), but furthermore, you must specify the kind of post-processing level ("prefix" of the field) and the value of this level. There are 5 possibilities, according to the level type as shown in the table 2.4.

  

Table 2.4: Prefix, unit and number of letters to write upper air fields prefix.

Level type	Prefix	Unit	Number of letters for level value
Pressure	P	Pascal	5
Height	H	Meter	5
Potential vorticity	V	deciPVU	3
Potential temperature	T	Kelvin	3
Eta	S	-	3

Example : temperature at 2 PVU is V020TEMPERATURE

Warning : fields on pressure levels bigger or equal to 1000 hPa are written out with truncated names ; for example, temperature at 1000 hPa is P00000TEMPERATURE while P00500TEMPERATURE could be as well the temperature at 5 hPa or the temperature at 1005 hPa !