Variables for ocean surface waves

[andrelanfer]

As discussed within the Sea-Ice and Ocean Task Team I would like to propose some new standard names, divided in 3 groups: total wave, swell wave and sea wave

Total Wave
Name: swh
Title: Total Significant Wave Height
CF Standard Name: ocean_surface_significant_wave_height
Units: m
Description: Wind driven surface gravity waves at the ocean surface, generated by the wave model , wave Height

Name: mpw
Title: Total Waves Mean Period
CF Standard Name: ocean_surface_wave_mean_period
Units: s
Description: Wind driven surface gravity waves at the ocean surface, generated by the wave model, mean period

Name: wpp
Title: Total Waves peak period
CF Standard Name: ocean_surface_wave_peak_period
Units: s
Description: Wind driven surface gravity waves at the ocean surface, generated by the wave model, spectral peak period

Name: wdir
Title: Total Waves Direction
CF Standard Name: ocean_surface_wave_direction
Units: degrees
Description: Wind driven surface gravity waves at the ocean surface, generated by the wave model, mean wave direction

Swell Wave

Name: swellswh
Title: Swell Significant Wave Height
CF Standard Name: ocean_surface_significant_wave_height_swell
Units: m
Description: Wind driven surface gravity waves at the ocean surface, generated by the wave model , swell wave height

Name: swellmpw
Title: Swell Waves Mean Period
CF Standard Name: ocean_surface_wave_mean_period_swell
Units: s
Description: Wind driven surface gravity waves at the ocean surface, generated by the wave model, swell mean period

Name: swellwpp
Title: swell waves peak period
CF Standard Name: ocean_surface_wave_peak_period_swell
Units: s
Description: Wind driven surface gravity waves at the ocean surface, generated by the wave model, swell spectral peak period

Name: swellwdir
Title: swell waves direction
CF Standard Name: ocean_surface_wave_direction_swell
Units: degrees
Description: Wind driven surface gravity waves at the ocean surface, generated by the wave model, swell mean wave direction

Sea Wave

Name: seaswh
Title: Sea Significant Wave Height
CF Standard Name: ocean_surface_significant_wave_height_sea
Units: m
Description: Wind driven surface gravity waves at the ocean surface, generated by the wave model , sea wave height

Name: sealmpw
Title: Sea waves mean period
CF Standard Name: ocean_surface_wave_mean_period_sea
Units: s
Description: Wind driven surface gravity waves at the ocean surface, generated by the wave model, sea mean period

Name: seawpp
Title: sea waves peak period
CF Standard Name: ocean_surface_wave_peak_period_sea
Units: s
Description: Wind driven surface gravity waves at the ocean surface, generated by the wave model, sea spectral peak period

Name: seawdir
Title: sea waves direction
CF Standard Name: ocean_surface_wave_direction
Units: degrees
Description: Wind driven surface gravity waves at the ocean surface, generated by the wave model, sea mean wave direction

Thank's for considering this proposal
Proposer's name: André Lanfer
Date: 16 September 2024

[github-actions]

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 @andrelanfer

Thanks for your proposals. I suspect that many or all of the quantities you wish to name can already be found in the standard name table, but they start with sea_surface, not ocean e.g. the first one is sea_surface_wave_significant_height. Please could you check?

Best wishes

Jonathan

[github-actions]

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Standard name moderators are also reminded to review @feggleton @japamment @efisher008

[efisher008]

Dear @andrelanfer,

Thank you for your proposal. The following names are already in the standard names table that I could find approximating your proposed terms:

• Your name: ocean_surface_significant_wave_height
  Table name: sea_surface_wave_significant_height
  Units: m

• Your name: ocean_surface_wave_mean_period
  Table name: sea_surface_wave_mean_period
  Units: s

• Your name: ocean_surface_wave_direction
  Table name: sea_surface_wave_from_direction
  Units: degrees

• Your name: ocean_surface_significant_wave_height_swell
  Table name: sea_surface_swell_wave_significant_height
  Units: m

• Your name: ocean_surface_wave_mean_period_swell
  Table name: sea_surface_swell_wave_mean_period
  Units: s

• Your name: ocean_surface_wave_direction_swell
  Table name: sea_surface_swell_wave_from_direction
  Units: degrees

I could not find any existing names relating to sea_surface and peak_period.

I also wanted to ask the difference between ocean_surface_significant_wave_height and ocean_surface_significant_wave_height_sea. Is the only distinction that ocean_surface_significant_wave_height_sea is specified in a "sea" area type? What is the reasoning for these being separate terms (and indeed the other names which only differ by adding the suffix _sea, e.g. ocean_surface_wave_peak_period_sea vs. ocean_surface_wave_peak_period)?

I also believe that your last name, seawdir, is meant to have the _sea suffix to distinguish it from the wdir term proposed above i.e. ocean_surface_wave_direction.

Thank you and kind regards,
Ellie Fisher

[ChrisBarker-NOAA]

I also wanted to ask the difference between ocean_surface_significant_wave_height and ocean_surface_significant_wave_height_sea.

In the wave world, we often make the distinction between "seas": the locally generated, shorter period waves, and "swell": the long period waves, usually generated far away. In many cases, there is a clear distinction between these in the wave spectrum.

I think that's what these mean:

ocean_surface_significant_wave_height: the significant wave height calculated from the entire spectrum.

ocean_surface_significant_wave_height_sea: the significant wave height calculated from just the "seas", i.e. the short period waves, portion of the spectrum.

[JonathanGregory]

I guess the distinction that @ChrisBarker-NOAA mentions is the one between "wind waves" and "swell waves". We already have distinct standard names for these, as well as combined ones e.g.

sea_surface_wave_significant_height
sea_surface_swell_wave_significant_height
sea_surface_wind_wave_significant_height

[ChrisBarker-NOAA]

yes, that's right :-) -- at least from my perspective, the OP might have a different definition of "seas" -- but looking now, I think my interpretation is correct -- "seas" == "wind waves"

[efisher008]

Dear @ChrisBarker-NOAA, @JonathanGregory,

If I interpreted your replies correctly, it would be appropriate to change your "sea wave" names (which use the suffix _sea refer to locally generated, shorter period waves) to instead include wind_wave? In doing so, they become these:

• ocean_surface_significant_wave_height_sea -> ocean_surface_significant_wind_wave_height

• ocean_surface_wave_mean_period_sea -> ocean_surface_wind_wave_mean_period -
  we have the existing standard name sea_surface_wind_wave_mean_period - is this suitable?

• ocean_surface_wave_peak_period_sea -> ocean_surface_wind_wave_peak_period

• ocean_surface_wind_wave_direction - there is the existing name sea_surface_wind_wave_directional_spread, but I'm not convinced this is describing the same quantity (the spread is "the directional width of the wind wave component of a sea").

The description of wind_wave in the CF phrase list is as follows:
"Wind waves are waves on the ocean surface and are the high frequency portion of a bimodal wave frequency spectrum."

Best wishes,
Ellie

[ChrisBarker-NOAA]

That (sea => wind_wave) looks good to me - -but we should get the OP's confirmation.

As for:
ocean_surface_wind_wave_direction
there is the existing name sea_surface_wind_wave_directional_spread

that is not the same -- again, we need to ask the OP -- but I think this is the existing:

sea_surface_wind_wave_from_direction

unless someone wants the "to" rather than "from" version.