Thanks you, Alison, Roy, Elodie and all -
Nan
On 6/22/16 9:32 AM, alison.pamment at stfc.ac.uk 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
> <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 19^th July.
>
> Best wishes,
>
> Alison
>
> ------
>
> Alison Pamment Tel: +44 1235 778065
>
> Centre for Environmental Data Analysis Email:
> alison.pamment at stfc.ac.uk <mailto:J.A.Pamment at rl.ac.uk>
>
> STFC Rutherford Appleton Laboratory
>
> R25, 2.22
>
> Harwell Campus, Didcot, OX11 0QX, U.K.
>
>
\
--
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* Nan Galbraith (508) 289-2444 *
* Upper Ocean Processes Group Mail Stop 29 *
* Woods Hole Oceanographic Institution *
* Woods Hole, MA 02543 *
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Received on Wed Jun 22 2016 - 09:02:15 BST
