Unknown Absorbers

RFM Examples

18APR24

Description

Similar to the limb radiance example, but, apart from specifying CO2, allowing the RFM to choose which other absorbers are significant in the chosen spectral range.

In the *GAS section the *(12) entry allows the RFM to add any other absorbers above a particular strength ('12' is 'quite strong') — inspecting the rfm.log file, it can be seen that it chooses to add H2O and F12 (CFC-12).

Since it was not known in advance whether the RFM will choose to add any molecular cross-section data (F12 in this case), there is an additional entry in the driver table: the *XSC containing a directory with various .xsc files. The RFM makes the substitution f12 for the * character in ../xsc/*.xsc and finds file f12.xsc (alternatively, the user could have explicity specifed various .xsc path/filenames in this section and the RFM would have inspected each searching for one, and only one, containing CFC-12 cross-sections).

Driver Table

*HDR 18APR24 RFM Example: unknown absorber selection *FLG RAD *SPC 935 940 0.0005 *GAS CO2 *(12) *ATM ../atm/usa.atm *TAN 20.0 *HIT ../hit/hitran_2016.bin *XSC ../xsc/*.xsc *END

Output Files

Output Spectrum

[plot.py]