Specify density profiles (or matrix, see below) of various traces gases to be included in the radiative transfer calculation. The entry of the input file looks like:
dens_file gas_species [unit] filename
At the moment following gas_species are included: ozone (O3), nitrogen dioxide (NO2), water vapor (H2O), bromine oxide (BRO), chlorine dioxide (OCLO), formaldehyde (HCHO), and carbon dioxide (CO2). The gas species is identified by their abbrevations given in the parenthesis above. unit is an optional argument to define the unit of the density. The profiles can be given in particles per cm3 (cm$ ^{-3}$ ), in particles per m3 (m$ ^{-3}$ ), as volume mixing ratio (vmr), as mass mixing ratio (mmr), or as relative humidity (only for water). The default for unit is cm$ ^{-3}$ . The model expects a density file with two columns:
1 Altitude above sea level in km.
2 The density of trace gas [in the specified unit]
The altitude grid may be different from that in atmosphere_file. All densities inside the range of the dens_file are replaced. For all other altitudes the values from the atmosphere_file are used. If the density is specified as -1 at a level, the value from atmosphere_file is used.

To scale the profile to a total column value use dens_column.

For airmass factor calculations it is for some species necessary to account for the variation of the profile with sza. This may be accomplished by specifying a dens_file in the following format:

0.0       SZA1      SZA2 ...
z(1)    dens(1,1)    ...
z(2)      .           .
 .        .           .
where z(i) are the altitude levels above sea level in km, SZA is the solar zenith angle in degrees, and dens is the density [in the specified unit] of the trace gases as function of solar zenith angle and altitude. The matrix may only be specified for one specie. It may however be combined with profiles of other species. A density matrix can only be used in connection with rte_solver sdisort!





Arve Kylling 2010-03-10