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
