Dear Andy Your new proposals of sections 1-3 following existing patterns, as you say, and look fine to me.
For those of section 4, can you say precisely what "one-sided directional width" means? The way you describe it, I wonder whether it could be described as a processed version of the wave_direction theta. For example, if it was the standard deviation of theta, cell_methods could describe it. Best wishes Jonathan ----- Forwarded message from "Saulter, Andrew" <[email protected]> ----- > Date: Wed, 2 May 2018 07:28:05 +0000 > From: "Saulter, Andrew" <[email protected]> > To: "[email protected]" <[email protected]> > Subject: Re: [CF-metadata] proposed additional names for sea_surface_wave > parameters > > Adding a minor amendment to the units for the > 'wave_energy_at_variance_spectral_density_maximum' parameters. These should > be 'm2 s' rather than 'm2s' in order to be parsed by UDUNITS. > > Andy > > From: CF-metadata [mailto:[email protected]] On Behalf Of > Saulter, Andrew > Sent: 01 May 2018 09:27 > To: [email protected] > Subject: [CF-metadata] proposed additional names for sea_surface_wave > parameters > > Hi all, > > Please find proposals for some additional sea_surface_wave parameters, which > will be provided as part of Met Office operational forecast products in the > near future. Hopefully nothing too contentious as mostly an extension of some > existing CF names. > > > 1. Addition of 'tertiary_swell' names for existing wave parameters > defined under 'wind_wave', 'primary_swell' and 'secondary_swell' categories. > So would add: > > sea_surface_tertiary_swell_wave_from_direction > units: degree > The quantity with standard name > sea_surface_tertiary_swell_wave_from_direction is the direction from which > the third most energetic swell waves are coming. Swell waves are waves on the > ocean surface and are the low frequency portion of a bimodal wave frequency > spectrum. The tertiary swell wave is the third most energetic swell wave. The > phrase "from_direction" is used in the construction X_from_direction and > indicates the direction from which the velocity vector of X is coming. The > direction is a bearing in the usual geographical sense, measured positive > clockwise from due north. > > sea_surface_tertiary_swell_wave_mean_period > units: s > The quantity with standard name sea_surface_tertiary_swell_wave_mean_period > is the mean period of the third most energetic swell waves. Swell waves are > waves on the ocean surface and are the low frequency portion of a bimodal > wave frequency spectrum. The tertiary swell wave is the third most energetic > wave in the low frequency portion of a bimodal wave frequency spectrum. A > period is an interval of time, or the time-period of an oscillation. Wave > period is the interval of time between repeated features on the waveform such > as crests, troughs or upward passes through the mean level. Wave mean period > is the mean period measured over the observation duration. > > sea_surface_tertiary_swell_wave_significant_height > Swell waves are waves on the ocean surface and are the low frequency portion > of a bimodal wave frequency spectrum. The tertiary swell wave is the third > most energetic wave in the low frequency portion of a bimodal wave frequency > spectrum. Significant wave height is a statistic computed from wave > measurements and corresponds to the average height of the highest one third > of the waves, where the height is defined as the vertical distance from a > wave trough to the following wave crest. > > > > 2. Addition of peak wave period parameter to 'wind_wave', > 'primary_swell', 'secondary_swell' and 'tertiary_swell' categories. This > follows the existing standard for > 'sea_surface_wave_period_at_variance_spectral_density_maximum' and adds: > > sea_surface_wind_wave_period_at_variance_spectral_density_maximum > units: s > The quantity with standard name > sea_surface_wind_wave_period_at_variance_spectral_density_maximum is the > period of the most energetic waves within the wind wave component of a sea. > Wind waves are waves on the ocean surface and are the high frequency portion > of a bimodal wave frequency spectrum. A period is an interval of time, or the > time-period of an oscillation. The phrase > "wave_period_at_variance_spectral_density_maximum", sometimes called peak > wave period, describes the period of the most energetic waves within a given > sub-domain of the wave spectrum. > > sea_surface_primary_swell_wave_period_at_variance_spectral_density_maximum > units: s > The quantity with standard name > sea_surface_primary_swell_wave_period_at_variance_spectral_density_maximum is > the period of the most energetic waves within the primary swell wave > component of a sea. Swell waves are waves on the ocean surface and are the > low frequency portion of a bimodal wave frequency spectrum. The primary swell > wave is the most energetic wave component in the low frequency portion of a > bimodal wave frequency spectrum. A period is an interval of time, or the > time-period of an oscillation. The phrase > "wave_period_at_variance_spectral_density_maximum", sometimes called peak > wave period, describes the period of the most energetic waves within a given > sub-domain of the wave spectrum. > > sea_surface_secondary_swell_wave_period_at_variance_spectral_density_maximum > units: s > The quantity with standard name > sea_surface_secondary_swell_wave_period_at_variance_spectral_density_maximum > is the period of the most energetic waves within the secondary swell wave > component of a sea. Swell waves are waves on the ocean surface and are the > low frequency portion of a bimodal wave frequency spectrum. The secondary > swell wave is the most energetic wave component in the low frequency portion > of a bimodal wave frequency spectrum. A period is an interval of time, or the > time-period of an oscillation. The phrase > "wave_period_at_variance_spectral_density_maximum", sometimes called peak > wave period, describes the period of the most energetic waves within a given > sub-domain of the wave spectrum. > > sea_surface_tertiary_swell_wave_period_at_variance_spectral_density_maximum > units: s > The quantity with standard name > sea_surface_tertiary_swell_wave_period_at_variance_spectral_density_maximum > is the period of the most energetic waves within the tertiary swell wave > component of a sea. Swell waves are waves on the ocean surface and are the > low frequency portion of a bimodal wave frequency spectrum. The tertiary > swell wave is the third most energetic wave component in the low frequency > portion of a bimodal wave frequency spectrum. A period is an interval of > time, or the time-period of an oscillation. The phrase > "wave_period_at_variance_spectral_density_maximum", sometimes called peak > wave period, describes the period of the most energetic waves within a given > sub-domain of the wave spectrum. > > > > 3. Addition of energy_at_variance_spectral_density_maximum parameter to > existing 'wind_wave', 'primary_swell', 'secondary_swell' and 'tertiary_swell' > categories. This follows the existing standard for > 'sea_surface_wave_energy_at_variance_spectral_density_maximum' and adds: > > sea_surface_wind_wave_energy_at_variance_spectral_density_maximum > units: m2s > The quantity with standard name > sea_surface_wind_wave_energy_at_variance_spectral_density_maximum is the > energy of the most energetic waves within the wind wave component of a sea. > Wind waves are waves on the ocean surface and are the high frequency portion > of a bimodal wave frequency spectrum. The phrase > "wave_energy_at_variance_spectral_density_maximum", sometimes called peak > wave energy, describes the maximum value of the > wave_variance_spectral_density within a given sub-domain of the wave spectrum. > > sea_surface_primary_swell_wave_energy_at_variance_spectral_density_maximum > units: m2s > The quantity with standard name > sea_surface_primary_swell_wave_energy_at_variance_spectral_density_maximum is > the energy of the most energetic waves within the primary swell wave > component of a sea. Swell waves are waves on the ocean surface and are the > low frequency portion of a bimodal wave frequency spectrum. The primary swell > wave is the most energetic wave component in the low frequency portion of a > bimodal wave frequency spectrum. The phrase > "wave_energy_at_variance_spectral_density_maximum", sometimes called peak > wave energy, describes the maximum value of the > wave_variance_spectral_density within a given sub-domain of the wave spectrum. > > sea_surface_secondary_swell_wave_energy_at_variance_spectral_density_maximum > units: m2s > The quantity with standard name > sea_surface_primary_swell_wave_energy_at_variance_spectral_density_maximum is > the energy of the most energetic waves within the secondary swell wave > component of a sea. Swell waves are waves on the ocean surface and are the > low frequency portion of a bimodal wave frequency spectrum. The secondary > swell wave is the second most energetic wave component in the low frequency > portion of a bimodal wave frequency spectrum. The phrase > "wave_energy_at_variance_spectral_density_maximum", sometimes called peak > wave energy, describes the maximum value of the > wave_variance_spectral_density within a given sub-domain of the wave spectrum. > > sea_surface_tertiary_swell_wave_energy_at_variance_spectral_density_maximum > units: m2s > The quantity with standard name > sea_surface_tertiary_swell_wave_energy_at_variance_spectral_density_maximum > is the energy of the most energetic waves within the tertiary swell wave > component of a sea. Swell waves are waves on the ocean surface and are the > low frequency portion of a bimodal wave frequency spectrum. The tertiary > swell wave is the third most energetic wave component in the low frequency > portion of a bimodal wave frequency spectrum. The phrase > "wave_energy_at_variance_spectral_density_maximum", sometimes called peak > wave energy, describes the maximum value of the > wave_variance_spectral_density within a given sub-domain of the wave spectrum. > > > > 4. And finally... Addition of 'directional_spreading' parameter to > 'sea_surface_wave', 'wind_wave', 'primary_swell', 'secondary_swell' and > 'tertiary_swell' categories. Giving the additional parameters: > > sea_surface_wave_directional_spread > units: degree > Directional spread is the (one-sided) directional width of the wave > directional spectrum, S(t,x,y,f,theta) where t is time, x and y are > horizontal coordinates (such as longitude and latitude), f is frequency and > theta is direction. > > sea_surface_wind_wave_directional_spread > units: degree > The quantity with standard name sea_surface_wind_wave_directional_spread is > the directional width of the wind wave component of a sea. Wind waves are > waves on the ocean surface and are the high frequency portion of a bimodal > wave frequency spectrum. The phrase "wave_directional_spread" describes is > the (one-sided) directional width within a given sub-domain of the wave > directional spectrum, S(t,x,y,f,theta) where t is time, x and y are > horizontal coordinates (such as longitude and latitude), f is frequency and > theta is direction . > > sea_surface_primary_swell_wave_directional_spread > units: degree > The quantity with standard name > sea_surface_primary_swell_wave_directional_spread is the directional width of > the primary swell wave component of a sea. Swell waves are waves on the ocean > surface and are the low frequency portion of a bimodal wave frequency > spectrum. The primary swell wave is the most energetic wave component in the > low frequency portion of a bimodal wave frequency spectrum. The phrase > "wave_directional_spread" describes is the (one-sided) directional width > within a given sub-domain of the wave directional spectrum, S(t,x,y,f,theta) > where t is time, x and y are horizontal coordinates (such as longitude and > latitude), f is frequency and theta is direction . > > sea_surface_secondary_swell_wave_directional_spread > units: degree > The quantity with standard name > sea_surface_secondary_swell_wave_directional_spread is the directional width > of the secondary swell wave component of a sea. Swell waves are waves on the > ocean surface and are the low frequency portion of a bimodal wave frequency > spectrum. The secondary swell wave is the second most energetic wave > component in the low frequency portion of a bimodal wave frequency spectrum. > The phrase "wave_directional_spread" describes is the (one-sided) directional > width within a given sub-domain of the wave directional spectrum, > S(t,x,y,f,theta) where t is time, x and y are horizontal coordinates (such as > longitude and latitude), f is frequency and theta is direction . > > sea_surface_tertiary_swell_wave_directional_spread > units: degree > The quantity with standard name > sea_surface_secondary_swell_wave_directional_spread is the directional width > of the tertiary swell wave component of a sea. Swell waves are waves on the > ocean surface and are the low frequency portion of a bimodal wave frequency > spectrum. The tertiary swell wave is the third most energetic wave component > in the low frequency portion of a bimodal wave frequency spectrum. The phrase > "wave_directional_spread" describes is the (one-sided) directional width > within a given sub-domain of the wave directional spectrum, S(t,x,y,f,theta) > where t is time, x and y are horizontal coordinates (such as longitude and > latitude), f is frequency and theta is direction . > > > Phew! > Many thanks > Andy > > Andy Saulter > Surge, Waves and Metocean Projects Manager > Met Office FitzRoy Road Exeter Devon EX1 3PB > Tel: +44 (0)1392 884703 Fax: +44 (0)1392 885681 > [email protected]<mailto:[email protected]> > http://www.metoffice.gov.uk > > _______________________________________________ > CF-metadata mailing list > [email protected] > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata ----- End forwarded message ----- _______________________________________________ CF-metadata mailing list [email protected] http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
