Thanks Alison.
I'm OK with the change from "average" to "mean".
Regards,
Elodie
On 22/06/2016 17:02, Nan Galbraith wrote:
> 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.
>>
>>
> \
>
Received on Wed Jun 22 2016 - 09:16:40 BST
