Coriolis selector and new schemes

[jm-c]

What changes does this PR introduce?

• add 2 new Coriolis schemes for vector-invariant formulation.
• add new (run-time) coriolis-scheme selector "selectCoriScheme"
  to replace (in src code) "useJamartWetPoints" and "useEnergyConservingCoriolis";

What is the current behaviour?

• multiple coriolis-scheme selector.

What is the new behaviour

• single coriolis-scheme selector (selectCoriScheme); keep full
  backward compatibility ; And add 2 new scheme for V.I.

Does this PR introduce a breaking change?

no.

Other information:

new scheme: selectCoriScheme=2 seems to conserve Angular-Momentum better
than other scheme.

Suggested addition to tag-index

o pkg/mom_vecinv:

• add 2 Coriolis schemes which satisfy: d/dt U = f V ; d/dt V = -f U
  (with U,V = vertically integrated flow).
• add new run-time coriolis-scheme selector "selectCoriScheme" to replace
  "useJamartWetPoints" and "useEnergyConservingCoriolis"; but keep these 2
  in namelist (backward compatible) to set "selectCoriScheme" accordingly.

[jm-c]

@jrscott : I trie to update the parameter table. Please check when you have time. Also, I choose a different
way to describle multiple choice, using "=2 : description ; =3 : description ...." instead of "2= description ; 3= description ...." I feel this new way more clear. But I did not change the few other multiple-choice params description. Something to decide.

[jrscott]

@jm-c I'll take a look and we can discuss this week

[jrscott]

@jm-c, I think we need to make some changes here. Between the ch 2 and ch 3 edits, was confused. Had the following questions:

• is the energy conserving form better? If so, might it be worth making this the default?
  ("for historical reasons" seems a poor explanation of defaulting to an inferior discretization...
  I realize this involves some work, perhaps can be grouped with another change affecting results)

• Unless I'm missing something, there seems no reason to keep the deprecated parameters in the manual (either the mentions in ch 2 or 3). We keep them in the namelists (in the code) but remove all traces in the documentation; this was done for a host of other deprecated parameters.

• I prefer the way I listed the options however I think I should replace my comma delimiter with a semi-colon, and I think it would be improved. I found using both the colon and semicolon confusing in regards to what grouped with what. Let's decide on this and I can change throughout.

[jrscott]

Perhaps the better plan is to make a table for the relevant section in ch 2 (similar idea as done for table 2.1) that explains these choices in greater detail, and refer to the table in the ch 3 parameter list table.
If you can explain the choices to me so I understand them better, I can do this :)

[christophernhill]

@jrscott to work with @jm-c on adding issue for the need for further tests beyond flat bottom atmos. Will also update PR to reference test experiment in verification_other which is WIP ( MITgcm/verification_other#2. ) pending this code merge

[jm-c]

Plan is to switch new experiment (in verification_other, atm_strato) to use one of the 2 new Coriolis scheme (selectCoriScheme=2). One of the advantage of this new scheme is to conserve Angular Momentum
(without topography) and this new aquaplanet-type experiment is good candidate to test it.

[christophernhill]

@jrscott to finish docs

@christophernhill looked at code. LGTM

[jrscott]

@jm-c I think (?) I brought this PR up to date and properly fixed the merge conflict in the parameter table (I did delete the two deprecated parms from the table too). Ball in @edoddridge's court now to point out what I did wrong :) But don't push the green button just yet, let me look at the ch 2 doc section.

[edoddridge]

Sure thing. I'll look at it this week, but won't merge it.

[jm-c]

@jrscott took a quick look at changes in section 3 tables. Looks good.
Since this PR code changes has been approved (as it) for some time now (since Apr 11), could we speed up a bit section 2 review to get closer to the merging point ?

[edoddridge]

I can't see any problems with your merge. 👍

[jrscott]

@jm-c please check this last change for accuracy. I removed the mention of the deprecrated parm. I basically did as we discussed, I believe, despite this section needing further attention.

When this is checked in -- I will create an issue that this section (and the VI:Coriolis section) need pretty serious overhaul, mention of Jamart etc.

[jm-c]

Would like to merge this soon (may be tomorrow). No major changes to the code for quite a long time

• I am waiting for this one to be merged to update this other PR: New atmosphere experiment (from Matt Kasoar) verification_other#2