Fixed pHcloud to be nonconstant and isCloud to vary

[sdabby]

Name and Institution (Required)

Name: Sierra Dabby
Institution: University of Washington

Describe the update

I edited sulfate_mod.F90 to fix the isCloud and pHCloud diagnostics. My edits start at line 2591 and end at 2605. Mainly, I just commented out some reset lines and added an if statement. The if statement says that if sulfate is online, don't reset the values of isCloud and pHCloud inside sulfate_mod.F90.

Expected changes

This update should make pHCloud vary, previously it would output pH as 4.5 everywhere. It should also allow isCloud to vary between 0 and 1, previously it was 0 everywhere.

Reference(s)

No lit citations.

Related Github Issue

Link to corresponding GitHub issue: [https://github.com//issues/3310]

[yantosca]

Thanks for this @sdabby and @mcdon1718-h. Would you also be able to add a sentence to the CHANGELOG.md such as

- Fixed error where `State_Chm%phCloud` was always being reset to 4.5

This can go at the bottom of the Fixed section

[yantosca]

@sdabby, @mcdon1718-h This looks good but we would need to add a sentence to the CHANGELOG.md as described on my other comment.

#3328 (comment)

[viral211]

Hi @yantosca and @mcdon1718-h, Becky asked me to look at this since I have worked on the cloud pH code before. Sierra's fix looks good to me as well.
But from looking at this code more broadly, I think it needs streamlining. The current flow is confusing, and there are duplicate functions in sulfate_mod and KPP (e.g., to calculate cloud pH). Anyone can easily make an error or introduce a bug when making changes to the sulfate chemistry. I know the GCST has their hands full, but it would be great if you could find time to tackle this.