Revision of section 2.12 (Lake Model) in technical note for CLM6

[nmizukami]

Description of changes

After review, I made a few minor edits and various corrections e.g., links, equations. etc. I did not change anything on roughness length update made by @olyson.

Specific changes I made:

• lots of tailing spaces are removed (due to my vim setting for rst file)
• Added "equation" before the equation number (to distinguish section numbers), but not sure if this was good change.
• Remove or update the section on changes since CLM4.
• Editorial change (2.12. Lake Model)- "atmosphere model of Hostetler et al. (1993), Hostetler et al. (1993)." Remove second "Hostetler et al. (1993)."
• Editorial change (2.12. Lake Model)- "spatially variable depth" to "spatially varying depth"
• Editorial change (2.12.1 vertical discretization) - "assumed depth" to "default depth"? Later the text says “default (50 m lake)”
• Equation style changes - Eqs. 2.12.13, 2.12.35 and 2.12.36.
• Eq's notation change (2.12.4.2 Surface Flux Solution). Eq. 2.12.21 L↑ should be L_g↑
• "light extinction coefficient varies between lake columns" based on eq. (2.12.46), I believe. It was empty.
• "If freezing occurs, Q_avail is again given by" what? I believe it is eq. 2,12.52.
• Fixed section references ("Monin-Obukhov Similarity Theory" for friction velocity, and "Surface Flux Solution Lake" for surface temperature solution). I believe these are correct references.

Specific notes

Contributors other than yourself, if any:

CTSM Issues Fixed (include github issue #): Resolve #3858

Are answers expected to change (and if so in what way)? N/A

Any User Interface Changes (namelist or namelist defaults changes)? N/A

Does this create a need to change or add documentation? Did you do so? Yes, This PR is for documentation change.

Testing performed, if any:

Built documentation on Casper (NCAR HPC) following the working with documentation guide, no errors.

[ekluzek]

The changes make sense to me. And cover the things talked about. Removal of the section about updates since the previous version is good.

@nmizukami changed so that equations have equation before it, which makes sense to me. He questioned if that's a good change. But, I think we should go with it. It might be something to look at later for consistency between chapters.

[olyson]

@nmizukami , during my review of and changes to the Surface Albedo chapter, I found that the description of lake albedos was outdated (it referred to the prescribed lake albedos from LSM). So I changed this in the Surface Albedo chapter to follow the current code for lake albedo. I'd suggest then to simply refer to the Surface Albedo chapter (specifically Section 2.3.2 Ground Albedos) in the lake chapter. That way we don't duplicate the text/equations. I think the Ground Albedo section is appropriate since it describes albedos for the different surface types.

[ekluzek]

@nmizukami this failed the checker in regard to curly quotes (since Sphynx will handle this). So you'll need to fix that before it can be merged. This should be straightforward, but I can show you if you have any questions.

[samsrabin]

You can see the offending curlies here.

I'm removing myself as reviewer since this isn't my bailiwick.