Here, f (λex) is the absorption factor at the excitation wavelength λex, F the integral emission intensity, i.e., the area under the blank and spectrally
corrected emission spectrum on a wavelength scale, and n the refractive index of the solvent (s) used.
I have seen the TOA
spectra you have referred to, I still can't explain the CO2
emission that appears to come from the tropopause, but I am certain that that is not the
correct explanation.