Hi Nan,
This goes beyond the scope of the current proposal, covering many existing Standard Names where I haven't proposed changes to the definition(I only fixed the real howlers) and all existing wave Standard Names that include 'sea_surface'. This causes me great concern as it sets us on a course of entangling a wide-ranging review of a significant number of additional Standard Name definitions with the howler fixing and the new names required by Marta and Elodie. The inevitable result of this course is that it will be months before we make any progress.
I have also received off-list feedback with wider implications for Standard Name definitions, but not the names themselves concerning the use of 'due North' and the definitions of 'wind wave' and 'swell wave'.
Consequently, how about a strategy of considering the three sub-proposals 'accepted' and getting them published as there is no remaining controversy over the new names and there is general agreement that the changed definitions whilst not perfect are significantly better than what is already there?
Once we've reached that milestone we can then work to produce a document proposing further improvements to the definitions across all wave Standard Names resulting in an internally consistent set of definitions.
Cheers, Roy.
Please note that I partially retired on 01/11/2015. I am now only working 7.5 hours a week and can only guarantee e-mail response on Wednesdays, my day in the office. All vocabulary queries should be sent to enquiries at bodc.ac.uk. Please also use this e-mail if your requirement is urgent.
________________________________
From: CF-metadata <cf-metadata-bounces at cgd.ucar.edu> on behalf of Nan Galbraith <ngalbraith at whoi.edu>
Sent: 14 June 2016 16:26
To: cf-metadata at cgd.ucar.edu
Subject: Re: [CF-metadata] Wave Direction, Energy and Steepness Sub-Proposal
Thanks, Roy, for all your work on this. I have a possibly belated
suggestion,
and one question.
I'd like to suggest that, where we have a definition of the 'main term'
such as
'sea_surface_swell_wave', we just change the order of the sentences in the
definition, with the main term being defined first, which would give us,
for
example,
*sea_surface_swell_wave_from_direction **
**Swell waves are the low frequency portion of a bimodal wave frequency
distribution. **
**"From_direction" is used in the construction X_from_direction and
indicates the direction **
**from which the velocity vector of X is coming. The direction is a
bearing in the usual **
**geographical sense, measured positive clockwise from due north.*
I tried to write this out for each of the definitions below, but the
email message's
formatting got the better of me, and I gave up.
My question is: are we using the term 'sea_surface' in a slightly
different way from other
places it appears in CF, like sea_surface_temperature? That seems to be
a deprecated
alias for skin temperature, and should not have a depth associated with
it. Do we need
to include a description of how this term is used in waves, as part of
these definitions?
Thanks!
Nan
On 6/1/16 9:06 AM, Lowry, Roy K. wrote:
> Dear All,
> Please find the third part of the wave Standard Name proposal. This
> includes changes to the definition for five of the six existing wave
> direction Standard names plus five new Standard names.
> Based on the proposal of Elodie and Marta with further off-list
> discussion by Chris Barker, nan Galbraith and myself.
> Cheers, Roy.
> *Changes to Existing Standard Name Definitions*
>
> 1. *sea_surface_swell_wave_from_direction *
>
> */Current Definition/*
> Swell waves are waves on the ocean surface. "from_direction" is used
> in the construction X_from_direction and indicates the direction from
> which the velocity vector of X is coming.
> */New Definition/*
> "From_direction" is used in the construction X_from_direction and
> indicates the direction from which the velocity vector of X is coming.
> The direction is a bearing in the usual geographical sense, measured
> positive clockwise from due north. Swell waves are the low frequency
> portion of a bimodal wave frequency distribution.
>
> 2. *sea_surface_swell_wave_to_direction*
>
> */Current Definition /*
> Swell waves are waves on the ocean surface. "to_direction" is used in
> the construction X_to_direction and indicates the direction towards
> which the velocity vector of X is headed. The direction is a bearing
> in the usual geographical sense, measured positive clockwise from due
> north.
> */New Definition/*
> "To_direction" is used in the construction X_to_direction and
> indicates the direction towards which the velocity vector of X is
> headed. The direction is a bearing in the usual geographical sense,
> measured positive clockwise from due north. Swell waves are the low
> frequency portion of a bimodal wave frequency distribution.
>
> 3. *sea_surface_wave_from_direction*
>
> */Current Definition /*
> 'from_direction' is used in the construction X_from_direction and
> indicates the direction from which the velocity vector of X is coming.
> */New Definition/*
> "From_direction" is used in the construction X_from_direction and
> indicates the direction from which the velocity vector of X is coming.
> The direction is a bearing in the usual geographical sense, measured
> positive clockwise from due north.
>
> 4. *sea_surface_wave_to_direction *
>
> */Current Definition - No Change Proposed /*
> "to_direction" is used in the construction X_to_direction and
> indicates the direction towards which the velocity vector of X is
> headed. The direction is a bearing in the usual geographical sense,
> measured positive clockwise from due north.
>
> 5. *sea_surface_wind_wave_from_direction *
>
> */Current Definition /*
> Wind waves are waves on the ocean surface. Wind is defined as a
> two-dimensional (horizontal) air velocity vector, with no vertical
> component. (Vertical motion in the atmosphere has the standard name
> "upward_air_velocity".) "from_direction" is used in the construction
> X_from_direction and indicates the direction from which the velocity
> vector of X is coming.
> */New Definition/*
> "From_direction" is used in the construction X_from_direction and
> indicates the direction from which the velocity vector of X is coming.
> The direction is a bearing in the usual geographical sense, measured
> positive clockwise from due north. Wind waves are the high frequency
> portion of a bimodal wave frequency distribution.
>
> 6. *sea_surface_wind_wave_to_direction *
>
> */Current Definition /*
> Wind waves are waves on the ocean surface. Wind is defined as a
> two-dimensional (horizontal) air velocity vector, with no vertical
> component. (Vertical motion in the atmosphere has the standard name
> "upward_air_velocity".) "to_direction" is used in the construction
> X_to_direction and indicates the direction towards which the velocity
> vector of X is headed. The direction is a bearing in the usual
> geographical sense, measured positive clockwise from due north.
> */New Definition/*
> "To_direction" is used in the construction X_to_direction and
> indicates the direction towards which the velocity vector of X is
> headed. The direction is a bearing in the usual geographical sense,
> measured positive clockwise from due north. Wind waves are the high
> frequency portion of a bimodal wave frequency distribution.
> *New Standard Names*
>
> 1. *sea_surface_wave_from_direction_at_spectral_peak*
>
> The direction from which the waves at the spectral peak are coming.
> The spectral peak comprises the most energetic waves encountered
> during the measurement period. The direction is a bearing in the usual
> geographical sense, measured positive clockwise from due north.
> Canonical units = degrees.
> **
>
> 2. *sea_surface_primary_swell_wave_from_direction*
>
> "From_direction" is used in the construction X_from_direction and
> indicates the direction from which the velocity vector of X is coming.
> The direction is a bearing in the usual geographical sense, measured
> positive clockwise from due north. The primary swell wave is the most
> energetic wave in the low frequency portion of a bimodal wave
> frequency distribution.
> Canonical units = degrees.
>
> 3. *sea_surface_secondary_swell_wave_from_direction*
>
> "From_direction" is used in the construction X_from_direction and
> indicates the direction from which the velocity vector of X is coming.
> The direction is a bearing in the usual geographical sense, measured
> positive clockwise from due north. The secondary swell wave is the
> second most energetic wave in the low frequency portion of a bimodal
> wave frequency distribution.
> Canonical units = degrees.
>
> 4. *sea_surface_wave_maximum_steepness*
>
> Wave steepness is defined as the ratio of the wave height divided by
> the wavelength. The maximum wave steepness is the greatest value
> observed during the observation period. Wave height is defined as the
> vertical distance from a wave trough to the following wave crest. The
> wavelength is the horizontal distance from this trough to the next
> trough.
>
> Canonical units = dimensionless.
>
> 5. *sea_wave_spectrum_peak_energy*
>
> The wave directional spectrum can be written as a five dimensional
> function S(t,x,y,f,theta) where t is time, x and y are horizontal
> coordinates (such as longitude and latitude), f is frequency and theta
> is direction. S has the standard name
> sea_surface_wave_directional_variance_spectral_density. S can be
> integrated over direction to give S1= integral(S dtheta) and this
> quantity has the standard name
> sea_surface_wave_variance_spectral_density. Wave spectrum peak energy
> is the maximum value of the variance spectral density (max(S1)).
> Canonical units = Square metre seconds (m^2.s)
> Please note that I partially retired on 01/11/2015. I am now only
> working 7.5 hours a week and can only guarantee e-mail response on
> Wednesdays, my day in the office. All vocabulary queries should be
> sent to _enquiries at bodc.ac.uk_ <mailto:enquiries at bodc.ac.uk>. Please
> also use this e-mail if your requirement is urgent.
> _________________________________ _
> This message (and any attachments) is for the recipient only. NERC is
> subject to the Freedom of Information Act 2000 and the contents of
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> is exempt from release under the Act. Any material supplied to NERC
> may be stored in an electronic records management system.
> _________________________________ _
>
>
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--
*******************************************************
* Nan Galbraith Information Systems Specialist *
* Upper Ocean Processes Group Mail Stop 29 *
* Woods Hole Oceanographic Institution *
* Woods Hole, MA 02543 (508) 289-2444 *
*******************************************************
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