Dear Andy and Jonathan, Thanks for looking at these names again. In fact, I think Jonathan's email did originally appear on the list on 5th October and the comments were taken into account.
I have accepted all seven names and included them in today's update (see separate posting for full list of today's changes). 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 Jonathan Gregory Sent: 14 October 2018 14:30 To: [email protected] Subject: [CF-metadata] standard names for sea surface roughness variables I think this email may not have made it to the list, owing to an email problem I've been having, so it's a few days late. Sorry. Dear Andy Thanks for your persistence and patience! Yes, I think are looking sensible now, as you say. > [Thinking even more long term, upwave/downwave slopes could be > assigned different values based on wave asymmetry, but lets not go > there yet...] ... but it is sufficient reason for future-proofing I think. I'm happy with all these except that I would suggest putting the component immediately before "slope", which is what it most closely applies to i.e. > sea_surface_wave_mean_square_x_slope > sea_surface_wave_mean_square_y_slope > sea_surface_mean_square_upwave_slope > sea_surface_mean_square_crosswave_slope This would be consistent with existing stdnames e.g. downward_x_stress_at_sea_ice_base land_ice_x_velocity Best wishes Jonathan ----- Forwarded message from "Saulter, Andrew" <[email protected]> ----- > Date: Fri, 5 Oct 2018 10:40:56 +0000 > From: "Saulter, Andrew" <[email protected]> > To: "[email protected]" <[email protected]> > Subject: Re: [CF-metadata] standard names for sea surface roughness > variables > > Dear Jonathon, > > Thanks a lot, that is really helpful. Whilst I appreciate your point > about whether or not '_upwave/_downwave' are necessary if MSS is > unsigned, I think it wold still be useful to have this since the > _mean_square_slope_*_direction may well get compared with > _wave_*_direction and/or _wind_*_direction. Since and these latter > follow a convention it is useful/necessary not to have any ambiguity > in how these are referenced. [Thinking even more long term, > upwave/downwave slopes could be assigned different values based on > wave asymmetry, but lets not go there yet...] > > So, I think we have enough now to summarise the proposed new names and see > how we are doing... > > Agreed so far (I think) from earlier mails: > > charnock_coefficient_for_surface_roughness_length_for_momentum_in_air > Units: 1 > Coefficient value, based on the Charnock (1955) empirical expression for > deriving surface_roughness_length_for_momentum_in_air over the ocean. The > surface called "surface" means the lower boundary of the atmosphere. > > sea_surface_wave_mean_square_slope > Units: 1 > Wave slope describes an aspect of sea surface wave geometry related to sea > surface roughness. Mean square slope describes a derivation over multiple > waves within a sea-state, for example calculated from moments of the wave > directional spectrum. > > sea_surface_wave_x_mean_square_slope > Units: 1 > Wave slope describes an aspect of sea surface wave geometry related to sea > surface roughness. Mean square slope describes a derivation over multiple > waves within a sea-state, for example calculated from moments of the wave > directional spectrum. "x" indicates that slope values are derived from vector > components along the grid x-axis. > > sea_surface_wave_y_mean_square_slope > Units: 1 > Wave slope describes an aspect of sea surface wave geometry related to sea > surface roughness. Mean square slope describes a derivation over multiple > waves within a sea-state, for example calculated from moments of the wave > directional spectrum. "y" indicates that slope values are derived from vector > components along the grid y-axis. > > Testing the new 'upwave' names: > > sea_surface_upwave_mean_square_slope_direction > Units: degree > Wave slope describes an aspect of sea surface wave geometry related to sea > surface roughness. Mean square slope describes a derivation over multiple > waves within a sea-state, for example calculated from moments of the wave > directional spectrum. " direction" is used to assign a directional axis along > which wave energy is travelling, with "upwave" used to indicate that this is > equivalent to a "from_direction". > > sea_surface_upwave_mean_square_slope > Units: 1 > Wave slope describes an aspect of sea surface wave geometry related to sea > surface roughness. Mean square slope describes a derivation over multiple > waves within a sea-state, for example calculated from moments of the wave > directional spectrum. "upwave" indicates that slope values are derived from > vector components along (parallel to) the axis from which waves are > travelling. > > sea_surface_crosswave_mean_square_slope > Units: 1 > Wave slope describes an aspect of sea surface wave geometry related to sea > surface roughness. Mean square slope describes a derivation over multiple > waves within a sea-state, for example calculated from moments of the wave > directional spectrum. "crosswave" indicates that slope values are derived > from vector components across (normal to) the axis from which waves are > travelling. > > Hope these are beginning to sound sensible :-) > > Cheers > Andy > > > -----Original Message----- > From: CF-metadata <[email protected]> On Behalf Of > Jonathan Gregory > Sent: 01 October 2018 18:29 > To: [email protected] > Subject: Re: [CF-metadata] standard names for sea surface roughness > variables > > Dear Andy > > Thanks. I think your suggestion of "upwind" is certainly clearer than "from" > (and "downwind" would be much better than "to"). Your middle options would be > fine. > > > Parallel component: > > sea_surface_wave_mean_square_slope_along_upwave_direction > > Normal component: > > sea_surface_wave_mean_square_slope_across_upwave_direction > > and your first options would be OK too, except I wonder if they'd be > better as > > > Parallel component: sea_surface_mean_square_upwave_slope > > Normal component: sea_surface_mean_square_crosswave_slope > > since it's the slope which is along or across the direction, and I made > crosswave into one word like upwave, upward, eastward, etc. I think I'd > prefer these shorter ones myself. > > But I still have a question about whether upwave and downwave need to be > distinguished anyway for a mean square slope. Isn't avg((dh/dx)^2) the same > regardless of the sign convention of x, if x is the wave direction? If it's > not, don't you have to say whether cross-wave is leftward or rightward, > correspondingly? > > Best wishes > > Jonathan > > > ----- Forwarded message from "Saulter, Andrew" > <[email protected]> ----- > > > Date: Mon, 1 Oct 2018 09:30:03 +0000 > > From: "Saulter, Andrew" <[email protected]> > > To: "[email protected]" <[email protected]> > > Subject: Re: [CF-metadata] standard names for sea surface roughness > > variables > > > > Good morning Jonathon, > > > > Was nice to have a weekend's reflection on this, not least because I also > > got a bit more feedback from some of my other waves colleagues (thanks > > Fabrice). > > > > A quick fundamental, the reason we need to have some form of 'along' and > > 'across' follows the same argument as the 'spread' conversation. Basically, > > wave energy in a given sea-state is not uni-directional, so we have a > > dominant/mean direction that gets calculated, but there will be a component > > of wave energy (with associated height, period, slope characteristics etc.) > > that runs normal to this. > > > > In terms of what the "direction" really is, the suggestion I've been given > > is "upwave", i.e. a wave equivalent of "upwind" and, therefore, same as > > "wave_from_direction" (correcting my initial suggestion of "to" in the > > previous post). > > > > This gives us a few choices for names I think? > > > > Least verbose: > > Direction: sea_surface_upwave_mean_square_slope_direction / > > sea_surface_wave_mean_square_slope_from_direction* > > Parallel component: sea_surface_upwave_mean_square_slope > > Normal component: sea_surface_cross_wave_mean_square_slope > > > > More verbose (but perhaps more clear?): > > Direction: sea_surface_upwave_mean_square_slope_direction / > > sea_surface_wave_mean_square_slope_from_direction* > > Parallel component: > > sea_surface_wave_mean_square_slope_along_upwave_direction > > Normal component: > > sea_surface_wave_mean_square_slope_across_upwave_direction > > > > More consistent with existing names (but possibly least clear?): > > Direction: sea_surface_wave_mean_square_slope_from_direction > > Parallel component: > > sea_surface_wave_mean_square_slope_along_from_direction > > Normal component: > > sea_surface_wave_mean_square_slope_across_from_direction > > > > * if we use _from_direction in conjunction with _upwave, then we need to > > add some text to link the two terms in the standard name definition. > > > > Any of these make sense? > > Cheers > > Andy > > > > PS. Devon is geographically 'up' from Cornwall - but definitely 'down' in > > terms of the quality of pasties, clotted cream and beer.... > > > > > > > > -----Original Message----- > > From: Jonathan Gregory <[email protected]> > > Sent: 28 September 2018 13:46 > > To: Saulter, Andrew <[email protected]> > > Cc: [email protected] > > Subject: Re: [CF-metadata] standard names for sea surface roughness > > variables > > > > 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 > > > > _______________________________________________ > > 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 > > _______________________________________________ > CF-metadata mailing list > [email protected] > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata ----- End forwarded message ----- ----- End forwarded message ----- _______________________________________________ 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
