This all looks great, Thanks all!
-CHB On Wed, Jun 22, 2016 at 6:32 AM, <[email protected]> wrote: > Dear Roy, Elodie, Nan, Jonathan, Chris, et al, > > > > Many thanks to Elodie for her original wave name proposals, to Roy for > doing so much work on designing a systematic approach to CF wave names and > to all those who have worked to improve these proposals on and off the > list. My apologies for taking a while to respond to this discussion. > > > > I think it is useful to continue Roy’s approach of breaking the original > set of proposals into three groups, so here I will address just the height > names. I will address the other sets of proposals separately. > > > > I note the discussion around the use of mean, maximum and minimum in the > standard name, rather than our more usual approach of placing such > information in the cell_methods attribute. We do already have eleven > existing names that refer to “wave_mean_period”. I looked back at the > original discussion of these names in 2006 in which it was agreed to use > “mean” in the name because wave quantities can be calculated in many and > diverse ways from the power spectrum and it is not useful to come up with > separate cell_methods for them all. I think Roy made a similar point > earlier on in this discussion. In fact, I don’t think that putting the > quantities in cell_methods would greatly reduce the number of new names > required in this instance. Also, I’m strongly in favour of Roy’s approach > of adopting as far as possible a consistent convention for all wave > standard names so I support the use of mean, maximum and minimum in these > proposals for consistency with the existing names. > > > > I note the general point made by Nan about the ordering of sentences in > the definitions of new wave names ( > http://mailman.cgd.ucar.edu/pipermail/cf-metadata/2016/058843.html). I’m > broadly supportive of adopting this approach as we go along (so this > doesn’t mean we need to review all existing wave name definitions during > the current discussion). I think the definitions of the wave height > proposals are in any case consistent with Nan’s approach. > > > > For the two mean_height names, I suggest a minor change in which we > replace the word “average” in the definitions with the word “mean” for > clarity and consistency with the names themselves, otherwise they look > fine. These two names would therefore be as follows: > > sea_surface_wave_mean_height (m) > > ‘Wave height is defined as the vertical distance from a wave trough to the > following wave crest. The mean wave height is the mean trough to crest > distance measured during the observation period.’ > > sea_surface_wave_mean_height_of_highest_tenth (m) > > ‘Wave height is defined as the vertical distance from a wave trough to the > following wave crest. The height of the highest tenth is defined as the > mean of the highest ten per cent of trough to crest distances measured > during the observation period.’ > > If Roy and Elodie are happy with this small change, then these names can > be accepted for publication. > > > > The remaining height names look fine and are accepted for publication in > the standard name table: > > > > sea_surface_wave_significant_height (m) (Modification to definition of > existing name) > > ‘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.’ > > > > sea_surface_wind_wave_significant_height (m) (Modification to definition > of existing name) > > ‘Wind waves are waves on the ocean surface and are the high 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.’ > > > > sea_surface_swell_wave_significant_height (m) (Modification to definition > of existing name) > > ‘Swell waves are waves on the ocean surface and are 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.’ > > > > sea_surface_primary_swell_wave_significant_height (m) > > ‘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 swell wave. 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.’ > > > > sea_surface_secondary_swell_wave_significant_height (m) > > ‘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 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.’ > > > > sea_surface_wave_maximum_height (m) > > ‘Wave height is defined as the vertical distance from a wave trough to the > following wave crest. The maximum wave height is the greatest trough to > crest distance measured during the observation period.’ > > > > sea_surface_wave_maximum_crest_height (m) > > ‘The crest is the highest point of a wave. Crest height is the vertical > distance between the crest and the calm sea surface. Maximum crest height > is the maximum value measured during the observation period.’ > > > > sea_surface_wave_maximum_trough_depth (m) > > ‘The trough is the lowest point of a wave. Trough depth is the vertical > distance between the trough and the calm sea surface. Maximum trough depth > is the maximum value measured during the observation period.’ > > > > The current status of these names can also be viewed in the CEDA > vocabulary editor: > http://cfeditor.ceda.ac.uk/proposals/1?status=active&namefilter=height+trough&proposerfilter=Roy+Elodie&descfilter=&unitfilter=&yearfilter=&commentfilter=&filter+and+display=Filter > . > > > > The next update of the standard name table will take place on 19th July. > > > > Best wishes, > > Alison > > ------ > > Alison Pamment Tel: +44 > 1235 778065 > > Centre for Environmental Data Analysis Email: > [email protected] <[email protected]> > > STFC Rutherford Appleton Laboratory > > R25, 2.22 > > Harwell Campus, Didcot, OX11 0QX, U.K. > > > > > > *From:* CF-metadata [mailto:[email protected]] *On Behalf > Of *Chris Barker > *Sent:* 13 May 2016 17:13 > *To:* Nan Galbraith > *Cc:* [email protected] > *Subject:* Re: [CF-metadata] Waves > > > > On Wed, May 11, 2016 at 9:18 AM, Nan Galbraith <[email protected]> > wrote: > > 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. > > > > works for me. > > > > Thanks, > > > > -CHB > > > > > > -- > > > Christopher Barker, Ph.D. > Oceanographer > > Emergency Response Division > NOAA/NOS/OR&R (206) 526-6959 voice > 7600 Sand Point Way NE (206) 526-6329 fax > Seattle, WA 98115 (206) 526-6317 main reception > > [email protected] > > _______________________________________________ > CF-metadata mailing list > [email protected] > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata > > -- Christopher Barker, Ph.D. Oceanographer Emergency Response Division NOAA/NOS/OR&R (206) 526-6959 voice 7600 Sand Point Way NE (206) 526-6329 fax Seattle, WA 98115 (206) 526-6317 main reception [email protected]
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