Dear Rob et al., I have reviewed all the comments submitted in this thread. There is clearly strong support for the addition of this name and the discussion seems to have reached agreement on the following:
sea_surface_wave_directional_spread_at_variance_spectral_density_maximum (Canonical unit: degree) 'The quantity with standard name sea_surface_wave_directional_spread_at_variance_spectral_density_maximum is the directional spread of the most energetic waves. Directional spread 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. For a given mean wave (beam) direction the quantity approximates half the root mean square width about the beam axis, as derived either directly from circular moments or via the Fourier components of the wave directional spectrum.' The name, units and definition are all consistent with existing names. This name is accepted for publication in the standard name table and will be added in the November update. Best wishes, Alison ------ Alison Pamment Tel: +44 1235 778065 NCAS/Centre for Environmental Data Archival Email: [email protected] STFC Rutherford Appleton Laboratory R25, 2.22 Harwell Oxford, Didcot, OX11 0QX, U.K. -----Original Message----- From: CF-metadata <[email protected]> On Behalf Of Alison Pamment - UKRI STFC Sent: 16 October 2018 15:50 To: 'Rob Thomas' <[email protected]>; Jonathan Gregory <[email protected]> Cc: [email protected] Subject: Re: [CF-metadata] Spectral wave direction spread parameter Dear Rob, Apologies that I haven't responded in this thread until today. I see from a quick scan of the comments that the name is pretty much agreed. I need to check through properly, and if all is in order then the name can be accepted and added in the next update to the table. I'll have a look now. Best wishes, Alison ------ Alison Pamment Tel: +44 1235 778065 NCAS/Centre for Environmental Data Archival Email: [email protected] STFC Rutherford Appleton Laboratory R25, 2.22 Harwell Oxford, Didcot, OX11 0QX, U.K. -----Original Message----- From: CF-metadata <[email protected]> On Behalf Of Rob Thomas Sent: 16 October 2018 15:31 To: Jonathan Gregory <[email protected]> Cc: [email protected] Subject: Re: [CF-metadata] Spectral wave direction spread parameter Hi Jonathon, Do you need any more details to progress this addition? I'm happy with Roy's updated definition. Cheers Rob -----Original Message----- From: CF-metadata [mailto:[email protected]] On Behalf Of [email protected] Sent: 28 September 2018 15:05 To: [email protected] Subject: CF-metadata Digest, Vol 185, Issue 47 Send CF-metadata mailing list submissions to [email protected] To subscribe or unsubscribe via the World Wide Web, visit http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata or, via email, send a message with subject or body 'help' to [email protected] You can reach the person managing the list at [email protected] When replying, please edit your Subject line so it is more specific than "Re: Contents of CF-metadata digest..." Today's Topics: 1. Re: Spectral wave direction spread parameter (Jonathan Gregory) 2. Re: standard names for sea surface roughness variables (Jonathan Gregory) 3. Re: Spectral wave direction spread parameter (Lowry, Roy K.) ---------------------------------------------------------------------- Message: 1 Date: Fri, 28 Sep 2018 12:26:39 +0000 From: Jonathan Gregory <[email protected]> To: Rob Thomas <[email protected]> Cc: "[email protected]" <[email protected]> Subject: Re: [CF-metadata] Spectral wave direction spread parameter Message-ID: <[email protected]> Content-Type: text/plain; charset="us-ascii" Dear Rob >From the responses it's clear we need a name for this. I'm a bit >nervous about "spread", which sounds vague to me. Can you clarify it? Best wishes and thanks Jonathan On Fri, Sep 28, 2018 at 07:47:51AM +0000, Rob Thomas wrote: > Date: Fri, 28 Sep 2018 07:47:51 +0000 > From: Rob Thomas <[email protected]> > To: "[email protected]" <[email protected]> > Subject: [CF-metadata] Spectral wave direction spread parameter > > Hi, > > > > Please can I propose/request a new standard name for the list: > "sea_surface_wave_directional_spread_at_variance_spectral_density_maximum" > > > > The rationale for this request is that in assessing our mappings of spectral > wave parameters to the CF standard names we have mapped "Peak Direction" > (described as "Dirp Direction for waves at peak of wave energy spectrum from > which the waves are coming") to > "sea_surface_wave_from_direction_at_variance_spectral_density_maximum" with > definition: > > > The quantity with standard name > sea_surface_wave_from_direction_at_variance_spectral_density_maximum is the > direction from which the most energetic waves are coming. The spectral peak > is the most energetic wave in the total wave spectrum. 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. The wave directional spectrum can be written as a five dimensional > function 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. S > has the standard name sea_surface_wave_directional_variance_spectral_density. > S can be integrated over direction to give S1= integral(S dtheta) and this > quantity has the standard name sea_surface_wave_variance_spectral_density. > > > > It does not appear there is an appropriate partner term for Peak Spread > (described as "Dsprp Directional spread of waves at peak of wave energy > spectrum") because the options currently available do not appear to tie in to > the peak wave energy spectrum/spectral peak information. > > > > Kind regards, > > Rob > > > > Dr. Rob Thomas > > Senior Data Analyst - European Data Management Projects Team Leader > > > > Marine Institute, Rinville, Oranmore, County Galway, H91 R673, Ireland > > Tel: (+)353 (0)91 387 409 > > Mob: (+)353 (0)87 952 3467 > > Email: [email protected]<mailto:[email protected]> > > ORCID: 0000-0001-6068-4924 > > Web: http://data.marine.ie/ > _______________________________________________ > CF-metadata mailing list > [email protected] > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata ------------------------------ Message: 2 Date: Fri, 28 Sep 2018 13:45:48 +0100 From: Jonathan Gregory <[email protected]> To: "Saulter, Andrew" <[email protected]> Cc: "[email protected]" <[email protected]> Subject: Re: [CF-metadata] standard names for sea surface roughness variables Message-ID: <[email protected]> Content-Type: text/plain; charset=us-ascii Dear Andy > Re the direction of the _mean_square_slope, the parameter and calculation > method from the wave spectrum is sufficiently different from that for > _wave_[to/from]_direction that it should stand alone. There has already been > a precedent set for this with waves, where different forms of parameter > calculation from the spectrum are given their own names because there is not > only a calculation difference but a different physical interpretation of each > parameter (e.g. the various type of wave period). OK, fair enough. So you need sea_surface_wave_mean_square_slope_to_direction. I'm still stuck with what this "direction" really is. Can we insert anything else for ? in sea_surface_wave_mean_square_slope_along_?_direction sea_surface_wave_mean_square_slope_across_?_direction Apparently you want to quantify the mean square slope along and across the direction of the mean square slope. Is that right? I'm not sure what it means. Without the "mean square", I'd think that the slope normal to the direction of the slope must be zero, but it must be more subtle than that in this case! Is there really an ambiguity of to/from with a mean square slope? It seems to me that it must be the same (unsigned) number regardless of whether you go backwards or forwards on a particular direction. Is Devon up or down from Cornwall? Best wishes Jonathan ------------------------------ Message: 3 Date: Fri, 28 Sep 2018 14:05:06 +0000 From: "Lowry, Roy K." <[email protected]> To: Jonathan Gregory <[email protected]>, Rob Thomas <[email protected]> Cc: "[email protected]" <[email protected]> Subject: Re: [CF-metadata] Spectral wave direction spread parameter Message-ID: <mm1p123mb13543b8afddd9ac7804e136899...@mm1p123mb1354.gbrp123.prod.outlook.com> Content-Type: text/plain; charset="windows-1252" Dear Jonathan, I seem to remember the 'what is spread' discussion coming up last time we encountered wave directional spread Standard Names. The Standard Name sea_surface_wave_directional_spread has the definition: Directional spread 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. For a given mean wave (beam) direction the quantity approximates half the root mean square width about the beam axis, as derived either directly from circular moments or via the Fourier components of the wave directional spectrum. This seems to have been omitted from Rob's definition, which should I think read: The quantity with the Standard Name sea_surface_wave_directional_spread_at_variance_spectral_density_maximum is the directional spread of the most energetic waves. Directional spread 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. For a given mean wave (beam) direction the quantity approximates half the root mean square width about the beam axis, as derived either directly from circular moments or via the Fourier components of the wave directional spectrum. Cheers, Roy. I have now retired but will continue to be active through an Emeritus Fellowship using this e-mail address. ________________________________ From: CF-metadata <[email protected]> on behalf of Jonathan Gregory <[email protected]> Sent: 28 September 2018 13:26 To: Rob Thomas Cc: [email protected] Subject: Re: [CF-metadata] Spectral wave direction spread parameter Dear Rob >From the responses it's clear we need a name for this. I'm a bit >nervous about "spread", which sounds vague to me. Can you clarify it? Best wishes and thanks Jonathan On Fri, Sep 28, 2018 at 07:47:51AM +0000, Rob Thomas wrote: > Date: Fri, 28 Sep 2018 07:47:51 +0000 > From: Rob Thomas <[email protected]> > To: "[email protected]" <[email protected]> > Subject: [CF-metadata] Spectral wave direction spread parameter > > Hi, > > > > Please can I propose/request a new standard name for the list: > "sea_surface_wave_directional_spread_at_variance_spectral_density_maximum" > > > > The rationale for this request is that in assessing our mappings of spectral > wave parameters to the CF standard names we have mapped "Peak Direction" > (described as "Dirp Direction for waves at peak of wave energy spectrum from > which the waves are coming") to > "sea_surface_wave_from_direction_at_variance_spectral_density_maximum" with > definition: > > > The quantity with standard name > sea_surface_wave_from_direction_at_variance_spectral_density_maximum is the > direction from which the most energetic waves are coming. The spectral peak > is the most energetic wave in the total wave spectrum. 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. The wave directional spectrum can be written as a five dimensional > function 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. S > has the standard name sea_surface_wave_directional_variance_spectral_density. > S can be integrated over direction to give S1= integral(S dtheta) and this > quantity has the standard name sea_surface_wave_variance_spectral_density. > > > > It does not appear there is an appropriate partner term for Peak Spread > (described as "Dsprp Directional spread of waves at peak of wave energy > spectrum") because the options currently available do not appear to tie in to > the peak wave energy spectrum/spectral peak information. > > > > Kind regards, > > Rob > > > > Dr. Rob Thomas > > Senior Data Analyst - European Data Management Projects Team Leader > > > > Marine Institute, Rinville, Oranmore, County Galway, H91 R673, Ireland > > Tel: (+)353 (0)91 387 409 > > Mob: (+)353 (0)87 952 3467 > > Email: [email protected]<mailto:[email protected]> > > ORCID: 0000-0001-6068-4924 > > Web: http://data.marine.ie/ data.marine.ie - Marine Environment<http://data.marine.ie/> data.marine.ie Marine Environment The investigation of Marine environments, Open Ocean, deep-sea, estuarine, coastal and near-shore zones and mans? impact on these areas. > _______________________________________________ > CF-metadata mailing list > [email protected] > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata _______________________________________________ CF-metadata mailing list [email protected] http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata ________________________________ This message (and any attachments) is for the recipient only. 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