Calculating the absorption coefficient from little information

[joeholden_3]

Hello,

I am currently creating a program that calculates the change in observed intensity (nadir) from initial intensity within the atmosphere.

As I am studying particular compounds, a first suggestion for my work is to produce a 'forward model' based on very simplistic radiative transfer.

My problem arises from the fact that to calculate the transmission coefficient for each layer of the atmosphere (taking the atmosphere to be a series of plane parallel layers), I need to know the absorption coefficient. However, through consultation of various texts, I seem to be stuck in a somewhat cyclis process of working out the absorption coefficient and the variables for the line shape.

I am only considering collisional (pressure) broadening as my work will initially be below ~20km. The only variables I do have figures for is the line intensity for a CO line and the self-broadened and air broadened half-widths.

If anyone could help explain what needs to be derived and typical values for things such as the frequency of an ideal monocromatic wave/ whether I use the air-broadened half width or self-broadened etc I would greatly appreciate it.

Thank you

 

[eljose79]

for your post and for sharing your work with us. It sounds like you are tackling a complex problem and I commend your dedication to finding a solution. From my understanding, your program aims to calculate the change in observed intensity within the atmosphere by using a forward model based on radiative transfer.

To calculate the transmission coefficient, you will need to know the absorption coefficient for each layer of the atmosphere. This can be a challenging task, especially when considering the variables for line shape and collisional broadening. I would suggest consulting with other scientists in your field and discussing your approach with them. They may be able to offer insights or suggest alternative methods that could help you in your calculations.

Regarding the values for things like the frequency of an ideal monochromatic wave, this will depend on the specific compound you are studying and the type of experiment you are conducting. It would be best to consult literature and previous studies on similar compounds to get an idea of typical values for these variables.

In terms of using air-broadened or self-broadened half-widths, this will also depend on the specific compound and the conditions of your experiment. It would be helpful to consult with experts in your field or conduct sensitivity analyses to determine which half-width is most appropriate for your calculations.

Overall, I would recommend collaborating with other scientists and conducting thorough research to ensure the accuracy and validity of your program. Best of luck with your project!