Switch off absorption by individual minor trace gases which are currently only included when mol_abs_param lowtran is chosen. The syntax is  

absorption species on/off

 
where species may be one of O4, N2, CO, SO2, NH3, NO, HNO3. By default all are switched on.

This option may also be used to turn on/off absorption by O4 in spectral resolution. It is on by default.