This is the Chevallier 91L diverse dataset in ARTS format. Both
arts-1-1 XML files and arts-1-0 plain ASCII files can be found
here. The files in old ARTS format are retained, because this dataset
should be particularly useful for model validation, e.g., to check
whether old and new ARTS give consistent results.

The dataset documentation by Chevallier is in file
"nwp_saf_profiles91.pdf". 

The original Chevallier data and the FORTRAN extraction program that
created these files can be found in
"~sbuehler/scalc/Chevallier_91L/arts_data". 

The z profile was generated with the hydrostatic assumption from the
surface pressure and elevation. (Using the hypsometric equation from
Wallace and Hobbs.)

The clear-sky atmospheric profiles are stored in:
chevallierl91_clear_X.xml (arts-1-1 format)
chevallierl91_clear_X.aa  (arts-1-0 format)

where X for the different data sets is: 
t   
q   
oz  
ccol
rcol

These files contain one matrix for each atmospheric state. (Each file
has 5000 states.) Each matrix row corresponds to one pressure
level. The meaning of the columns is:

p[Pa] T[K] z[m] H2O_VMR[1] O3_VMR[1]        

Clear-sky here refers to what is stored in the files, not the
scenarios, which do contain also cloudy cases.

It is forseen to later generate two more files for each data set:
chevallierl91_cloud_X.xml
chevallierl91_surface_X.xml

The first would contain IWC and LWC profiles, the second surface
parameters (T, wind speed).

All three files would hold all state information for RT calculations
with clouds and variable surface conditions.

Let me know if anything here is unclear, so that I can fix it.

2007-10-23 Stefan Buehler
