Standard names: *Reynolds stresses from gravity wave parameterizations*

[petrsacha]

Dear all,

on behalf of DynVarMIP, I need to define several new variables for outputing gravity wave momentum fluxes from parameterization schemes.

Currently, there is an existing standard name: atmosphere_eastward_stress_due_to_gravity_wave_drag However, this is inaccurate (we need to output stress connected with gravity waves and only its divergence leads to drag).

I propose the following new names: Westward Reynolds stress from orographic gravity wave parameterization - tauuogw, for the vertical flux of zonal momentum within the orographic GW parameterization. Northward Reynolds stress from orographic gravity wave parameterization - tauvogw, for the vertical flux of meridional momentum within the orographic GW parameterization. Westward Reynolds stress from non-orographic gravity wave parameterization - tauunogw, for the vertical wave flux of zonal momentum within the non-orographic GW parameterization. Northward Reynolds stress from non-orographic gravity wave parameterization - tauvnogw, for the vertical wave flux of meridional momentum within the non-orographic GW parameterization.

All have units [Pa].

Best regards, Petr Šácha.

[github-actions[bot]]

Thank you for your proposal. These terms will be added to the cfeditor (http://cfeditor.ceda.ac.uk/proposals/1) shortly. Your proposal will then be reviewed and commented on by the community and Standard Names moderator.

[JonathanGregory]

Dear @petrsacha

Thanks for your proposal. The standard name table already contains these quantities:

upward_eastward_momentum_flux_in_air_due_to_nonorographic_eastward_gravity_waves
upward_eastward_momentum_flux_in_air_due_to_nonorographic_westward_gravity_waves
upward_eastward_momentum_flux_in_air_due_to_orographic_gravity_waves

which are all in Pa. Following that pattern, I think your quantities could be named

upward_westward_momentum_flux_in_air_due_to_orographic_gravity_waves
upward_northward_momentum_flux_in_air_due_to_orographic_gravity_waves
upward_westward_momentum_flux_in_air_due_to_nonorographic_gravity_waves
upward_northward_momentum_flux_in_air_due_to_nonorographic_gravity_waves

Would that be correct? They could be downward_ instead of upward_ if that's what you need.

Best wishes

Jonathan

[petrsacha]

Dear Jonathan,

many thanks, this is correct. Exactly the same physical parameter. Thank you for noticing this.

Based on the proposed parameter, I defined several variables. Are they invalid then?

Best, Petr.

Od: JonathanGregory @.> Datum: neděle, 8. září 2024 v 23:43 Komu: cf-convention/vocabularies @.> Kopie: Petr Šácha @.>, Mention @.> Předmět: Re: [cf-convention/vocabularies] Standard names: Reynolds stresses from gravity wave parameterizations (Issue #217)

Dear @petrsachahttps://github.com/petrsacha

Thanks for your proposal. The standard name table already contains these quantities:

upward_eastward_momentum_flux_in_air_due_to_nonorographic_eastward_gravity_waves

upward_eastward_momentum_flux_in_air_due_to_nonorographic_westward_gravity_waves

upward_eastward_momentum_flux_in_air_due_to_orographic_gravity_waves

which are all in Pa. Following that pattern, I think your quantities could be named

upward_westward_momentum_flux_in_air_due_to_orographic_gravity_waves

upward_northward_momentum_flux_in_air_due_to_orographic_gravity_waves

upward_westward_momentum_flux_in_air_due_to_nonorographic_gravity_waves

upward_northward_momentum_flux_in_air_due_to_nonorographic_gravity_waves

Would that be correct? They could be downward instead of upward if that's what you need.

Best wishes

Jonathan

— Reply to this email directly, view it on GitHubhttps://github.com/cf-convention/vocabularies/issues/217#issuecomment-2336833754, or unsubscribehttps://github.com/notifications/unsubscribe-auth/BLBJ77GHJPHFH7FWZY3HESDZVTAIRAVCNFSM6AAAAABNWEOEN2VHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDGMZWHAZTGNZVGQ. You are receiving this because you were mentioned.Message ID: @.***>

[JonathanGregory]

Dear Petr

Based on the proposed parameter, I defined several variables. Are they invalid then?

I'm sorry, I don't follow your meaning. Where did you define variables?

If my suggestion is correct about the quantities you are asking about, you do still need four new stadard names. My proposal gives them the same pattern as existing standard names.

Best wishes

Jonathan

[petrsacha]

Dear Jonathan,

I am sorry for the confusion. For context, based on this Github proposal I asked for several variables within the CMIP7 data request. I will just comment on them and mention the already existing identical physical parameter you informed me about.

Best regards, Petr. Od: JonathanGregory @.> Datum: úterý, 10. září 2024 v 15:22 Komu: cf-convention/vocabularies @.> Kopie: Petr Šácha @.>, Mention @.> Předmět: Re: [cf-convention/vocabularies] Standard names: Reynolds stresses from gravity wave parameterizations (Issue #217)

Dear Petr

Based on the proposed parameter, I defined several variables. Are they invalid then?

I'm sorry, I don't follow your meaning. Where did you define variables?

If my suggestion is correct about the quantities you are asking about, you do still need four new stadard names. My proposal gives them the same pattern as existing standard names.

Best wishes

Jonathan

— Reply to this email directly, view it on GitHubhttps://github.com/cf-convention/vocabularies/issues/217#issuecomment-2340764257, or unsubscribehttps://github.com/notifications/unsubscribe-auth/BLBJ77C3F43XRAPMFIYGI6DZV3W7VAVCNFSM6AAAAABNWEOEN2VHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDGNBQG43DIMRVG4. You are receiving this because you were mentioned.Message ID: @.***>

[JonathanGregory]

Dear Petr

Thanks for explaining about variables. As you say, I don't think it's a problem for CMIP7 to change standard names at this point in the process. However, I think you will require four new standard names. The quantities you want to use don't have standard names at present. My suggestion was to change your proposal to use names which follow the same pattern as existing ones.

By the way, if you reply by email, it is not necessary to include the previous messages in your reply. On GitHub they can all be seen anyway in the discussion of the issue, https://github.com/cf-convention/vocabularies/issues/217

Best wishes

Jonathan

[petrsacha]

Dear Jonathan,

as I wrote before, I like your suggestion for the names. Should I do anything in this regard?

Best regards, Petr.

[JonathanGregory]

Dear Petr

Ah, OK. I had misunderstood. Thanks. In that case, the proposal is for

upward_westward_momentum_flux_in_air_due_to_orographic_gravity_waves
upward_northward_momentum_flux_in_air_due_to_orographic_gravity_waves
upward_westward_momentum_flux_in_air_due_to_nonorographic_gravity_waves
upward_northward_momentum_flux_in_air_due_to_nonorographic_gravity_waves

which all have canonical unit of Pa. They need descriptions, but I think that these can be constructed from standard phrases used to describe other standard names. For comparison, the description of the existing standard name upward_eastward_momentum_flux_in_air_due_to_nonorographic_eastward_gravity_waves is

The specification of a physical process by the phrase due_to_process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. "Upward" indicates a vector component which is positive when directed upward (negative downward). "Eastward" indicates a vector component which is positive when directed eastward (negative westward). "Upward eastward" indicates the ZX component of a tensor. An upward eastward momentum flux is an upward flux of eastward momentum, which accelerates the upper medium eastward and the lower medium westward. Momentum flux is dimensionally equivalent to stress and pressure. In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. The total upward eastward momentum flux due to gravity waves is the sum of the fluxes due to orographic gravity waves and nonorographic waves. The upward eastward momentum flux due to orographic gravity waves has the standard name upward_eastward_momentum_flux_in_air_due_to_orographic_gravity_waves. The total upward eastward momentum flux due to nonorographic gravity waves is the sum of the fluxes due to eastward and westward propagating waves. The latter has the standard name upward_eastward_momentum_flux_in_air_due_to_nonorographic_westward_gravity_waves.

Based on this pattern, I think the description for upward_westward_momentum_flux_in_air_due_to_orographic_gravity_waves, as an example, would be

The specification of a physical process by the phrase due_to_process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. "Upward" indicates a vector component which is positive when directed upward (negative downward). "Westward" indicates a vector component which is positive when directed westward (negative eastward). "Upward westward" indicates the -ZX component of a tensor. An upward westward momentum flux is an upward flux of westward momentum, which accelerates the upper medium westward and the lower medium eastward. Momentum flux is dimensionally equivalent to stress and pressure. In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. The total upward westward momentum flux due to gravity waves is the sum of the fluxes due to orographic gravity waves and nonorographic waves. The latter has the standard name upward_westward_momentum_flux_in_air_due_to_nonorographic_gravity_waves.

Do you agree? If so, I expect the standard name moderators can construct something similar for the other three from their phrasebank.

Best wishes

Jonathan

[petrsacha]

Dear Jonathan,

I completely agree. There is nothing more I can add.

Many thanks for helping with this issue.

Best regards, Petr.

[JonathanGregory]

Dear Petr

Fine - thanks for the proposal. They will be a useful addition. Best wishes

Jonathan

[martinjuckes]

@japamment : have the four revised terms proposed by Jonathan above been added to the editor?

[efisher008]

Dear @petrsacha, @JonathanGregory, @martinjuckes,

The four revised terms have been added to the editor by @japamment and I have just modified the term names to what was suggested by Jonathan above. I have also added the descriptions for the last two names based on the construction in the same post.

Could you provide an example of the description for upward_westward_momentum_flux_in_air_due_to_orographic_gravity_waves and upward_northward_momentum_flux_in_air_due_to_orographic_gravity_waves, as this doesn't quite match the construction of the existing name upward_eastward_momentum_flux_in_air_due_to_nonorographic_eastward_gravity_waves given as an example. Is the meaning of `upward_westward_momentum_flux_in_air_due_to_orographic_gravity_waves`` the same as this, but just in the inverse?

Best regards, Ellie

[petrsacha]

Dear all,

I am sorry for this. After reading all the above again, there is no need to construct new names upward_westward_momentum_flux_in_air_due_to_orographic_gravity_waves upward_westward_momentum_flux_in_air_due_to_nonorographic_gravity_waves This is indeed only the inverse of the existing names with eastward and according to the sign convention should be positive when directed eastward. (The original names are correct in this sense).

On the other side, we still need to define new names for the meridional fluxes. upward_northward_momentum_flux_in_air_due_to_orographic_gravity_waves upward_northward_momentum_flux_in_air_due_to_nonorographic_gravity_waves

The descriptions follow the pattern suggested by Jonathan above: upward_northward_momentum_flux_in_air_due_to_nonorographic_eastward_gravity_waves

The specification of a physical process by the phrase due_to_process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. "Upward" indicates a vector component which is positive when directed upward (negative downward). "northward" indicates a vector component which is positive when directed northward (negative southward). "Upward northward" indicates the ZY component of a tensor. An upward northward momentum flux is an upward flux of northward momentum, which accelerates the upper medium northward and the lower medium southward. Momentum flux is dimensionally equivalent to stress and pressure. In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. The total upward northward momentum flux due to gravity waves is the sum of the fluxes due to orographic gravity waves and nonorographic waves. The upward northward momentum flux due to orographic gravity waves has the standard name upward_northward_momentum_flux_in_air_due_to_orographic_gravity_waves. The total upward northward momentum flux due to nonorographic gravity waves is the sum of the fluxes due to eastward and westward propagating waves. The latter has the standard name upward_northward_momentum_flux_in_air_due_to_nonorographic_westward_gravity_waves.

analogical description is then for upward_northward_momentum_flux_in_air_due_to_nonorographic_westward_gravity_waves and upward_northward_momentum_flux_in_air_due_to_orographic_gravity_waves

Best regards, Petr.

[JonathanGregory]

That looks fine to me. Thanks, Petr @petrsacha.

[efisher008]

Thank you Petr @petrsacha, I have removed the two westward names, leaving only the meridional flux terms. I will come back to the meridional term descriptions shortly.

Best regards, Ellie

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