I would like to know how to obtain the value of rhot - rhor.

[SidneyCCCC]

I conducted the case study you suggested on "Intercomparison between the different atmospheric components," and found that when replacing s.ang.thetas with values below 20°, there is a significant discrepancy between rhor + results[key] + rhowl * tr and rhot. What could be the reason for this?
I would like to know how to obtain the value of rhot - rhor？
Thanks a lot for your help！

[SidneyCCCC]

When I set both the view angle and s.ang.thetas to 0, as shown in the figure.