Documentation changes for issue #3722 (dewpoint temperature restriction on bare ground dew flux)

[olyson]

Description of changes

Add documentation for dewpoint temperature restriction on bare ground dew flux

Specific notes

Contributors other than yourself, if any: None

CTSM Issues Fixed (include github issue #):
Resolves #3722
Are answers expected to change (and if so in what way)? No

Any User Interface Changes (namelist or namelist defaults changes)? No

Does this create a need to change or add documentation? Did you do so? Yes. Yes.

Testing performed, if any:
Built and viewed documentation locally.

[slevis-lmwg]

Thanks @olyson! I did not go to the code to confirm the accuracy of the equations, but nothing stood out as an obvious (to me) mistake, so I'm approving.

I noticed that you presented the new equations without saying anything about how this changes dew formation. Is dew formation explained anywhere? Is the connection to dew formation too tenuous to draw the link explicitly? Mainly I'm curious, and I'm fine with whatever you decide.

[olyson]

Thanks @olyson! I did not go to the code to confirm the accuracy of the equations, but nothing stood out as an obvious (to me) mistake, so I'm approving.

I noticed that you presented the new equations without saying anything about how this changes dew formation. Is dew formation explained anywhere? Is the connection to dew formation too tenuous to draw the link explicitly? Mainly I'm curious, and I'm fine with whatever you decide.

Actually, yes, that is a good idea. I will ex;plicitly link this to the RRTMGP error issue with a comment.

[olyson]

@slevis-lmwg , I have added the comment and fixed the numbering.

[wwieder]

@samsrabin can you bring this to b4b-dev?