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[CF-metadata] wind stress names

From: Nan Galbraith <ngalbraith>
Date: Wed, 23 May 2018 11:27:28 -0400

Hello again -

It looks like these are the names that are available in CF, with
definitions and units.
I'd like to propose aliases that contain the word wind, because these
are not easy
to find.? Also, I'd like a*direction_of_wind_stress variable*, or, if
there's opposition
to including the word wind, *direction_of_surface_downward_stress*.

(On a side note, I have no idea why there's a 'correction' variable -
what can that
mean?)

As far as the Seadatanet terms, I know they exist, but I'm not sure what
their relationship
is to the CF vocabulary.

|Thanks very much - Nan Galbraith|

|*- magnitude_of_surface_downward_stress*
The surface called "surface" means the lower boundary of the atmosphere.
"magnitude_of_X" means magnitude of a vector X. "Downward" indicates a
vector component which is positive when directed downward (negative
upward). Pa

*- surface_downward_northward_stress *(also for eastward)
The surface called "surface" means the lower boundary of the atmosphere.
"Northward" indicates a vector component which is positive when directed
northward (negative southward). "Downward" indicates a vector component
which is positive when directed downward (negative upward). "Downward
northward" indicates the ZY component of a tensor. A downward northward
stress is a downward flux of northward momentum, which accelerates the
lower medium northward and the upper medium southward. The surface
downward stress is the windstress on the surface.? Pa

*- surface_downward_x_stress *(also for y)
The surface called "surface" means the lower boundary of the atmosphere.
"x" indicates a vector component along the grid x-axis, positive with
increasing x. "Downward" indicates a vector component which is positive
when directed downward (negative upward).???? Pa

*- **surface_downward_x_stress_correction*
"x" indicates a vector component along the grid x-axis, positive with
increasing x. "Downward" indicates a vector component which is positive
when directed downward (negative upward). The surface called "surface"
means the lower boundary of the atmosphere. A downward x stress is a
downward flux of momentum towards the positive direction of the model's
x-axis.? Pa


|

On 5/16/18 10:43 AM, Blanc Fr?d?rique wrote:
> You can look at SEADTANET standard vocabularies, P01, P02 and P03:
>
> https://www.seadatanet.org/
>
>> -----Message d'origine-----
>> De : CF-metadata <cf-metadata-bounces at cgd.ucar.edu> De la part de Nan Galbraith
>> Envoy? : mercredi 16 mai 2018 16:29
>> Objet : [CF-metadata] wind stress names
>>
>> Hi all -
>>
>> I'm looking for a standard names for wind stress (direction and
>> magnitude, degree and
>> N/m^2, respectively), which are outputs of the COARE surface flux algorithm.
>>
>> I did a search of the standard names and didn't find anything* that
>> seemed appropriate.
>>
>> The Wikipedia definition of wind stress is:
>>
>> wind stress is the shear stress exerted by the wind on the surface
>> of large bodies of
>> water. It is the force component parallel to the surface, per unit
>> area, as applied by
>> the wind on the water surface.
>>
>> A search of the email list turned up a discussion of wind stress
>> divergence and curl, copied
>> below. I'm almost sure we've discussed this before, but either my email
>> archive isn't complete
>> or these terms weren't in the subject lines of the discussion.
>>
>> I'd like to propose these new names, unless these concepts are already
>> there using different
>> terms.
>>
>> Thanks - Nan Galbraith
>>
>
>
> On 9/23/16 10:47 AM, Bruce Hackett wrote:
>> Picking this up again after a long silence.
>>
>> I have been discussing this with my colleagues at KNMI and have gotten
>> some comments from Alison Pamment (thanks). The conclusion is that we
>> would like to revise the suggestion somewhat.
>>
>> The proposal for the wind stress divergence is essentially unchanged,
>> we just add the units.
>>
>> The proposal for the wind stress curl is modified to bring it in line
>> with what we are producing, which is the vertical component (indeed a
>> scalar!).
>>
>> We hope this will be acceptable to the community.
>>
>> The revised proposal is:
>> -------------------------------
>>
>> standard_name: divergence_of_surface_downward_stress
>> units: N/m^3
>> Description: 'The divergence is a signed scalar that represents the
>> magnitude of the 2D surface wind downward stress vector field's source
>> (positive) or sink (negative) at a given point. The surface called
>> "surface" means the lower boundary of the atmosphere. "Downward"
>> indicates a downward flux of momentum, which accelerates the lower
>> medium along the vector and the upper medium against the vector. The
>> surface downward stress is the wind stress on the surface.'
>>
>> --------------------------------
>>
>> standard_name: vertical_component_of_surface_downward_stress_curl
>> units: N/m^3
>> 'The vertical component of the stress curl is a signed scalar that
>> represents the magnitude of the 2D surface wind downward stress vector
>> field's local anti-clock-wise rotation at a given point; clockwise
>> rotation is thus given as negative curl. The surface called "surface"
>> means the lower boundary of the atmosphere. "Downward" indicates a
>> downward flux of momentum, which accelerates the lower medium along
>> the vector and the upper medium against the vector. The surface
>> downward stress is the wind stress on the surface.'
>>
>> Best regards,
>> Bruce
>>
>>
>> 2016-03-08 9:37 GMT+01:00 Bruce Hackett <bruceh at met.no
>> <mailto:bruceh at met.no>>:
>>
>> Here are proposed definitions provided by my colleague Ad
>> Stoffelen at KNMI:
>>
>> -------------------------------
>>
>> divergence_of_surface_downward_stress
>>
>> The divergence is a signed scalar that represents the magnitude of
>> the 2D surface wind downward stress vector field's source
>> (positive) or sink (negative) at a given point. The surface called
>> "surface" means the lower boundary of the atmosphere. "Downward"
>> indicates a downward flux of momentum, which accelerates the lower
>> medium along the vector and the upper medium against the vector.
>> The surface downward stress is the wind stress on the surface.
>>
>> --------------------------------
>>
>> curl_of_surface_downward_stress
>>
>> The curl is a signed scalar that represents the magnitude of the
>> 2D surface wind downward stress vector field's local
>> anti-clock-wise rotation at a given point; clockwise rotation is
>> thus given as negative curl. The surface called "surface" means
>> the lower boundary of the atmosphere. "Downward" indicates a
>> downward flux of momentum, which accelerates the lower medium
>> along the vector and the upper medium against the vector. The
>> surface downward stress is the wind stress on the surface.
>>
>>
>> Best regards,
>> Bruce
>>
>>
>> ----------------------------------------------------------------------
>>
>>
>> Message: 1
>> Date: Tue, 19 Jan 2016 16:41:17 +0000
>> From: Jonathan Gregory <j.m.gregory at reading.ac.uk
>> <mailto:j.m.gregory at reading.ac.uk>>
>> Subject: [CF-metadata] standard_names for wind stress curl, wind
>> stress divergence
>>
>>
>> Dear Bruce
>>
>> > If there are indeed no standard_names that are appropriate,
>> I would like to suggest the following:
>> > divergence_of_surface_downward_stress
>> > curl_of_surface_downward_stress
>>
>> I don't think we have named those before and your proposals
>> look like the
>> natural choice to me. If you could provide definitions (like
>> those most
>> quantities have in the table) and canonical units that will
>> constitute a
>> proposal. People may then comment and when it seems that the
>> discussion is
>> over, if they are agreed, they'll be added to the list.
>>
>> Best wishes and thanks
>>
>> Jonathan
>>
>>
>>
>>
>> --
>>
>>
>> 2016-03-08 9:37 GMT+01:00 Bruce Hackett <bruceh at met.no
>> <mailto:bruceh at met.no>>:
>>
>> Here are proposed definitions provided by my colleague Ad
>> Stoffelen at KNMI:
>>
>> -------------------------------
>>
>> divergence_of_surface_downward_stress
>>
>> The divergence is a signed scalar that represents the magnitude of
>> the 2D surface wind downward stress vector field's source
>> (positive) or sink (negative) at a given point. The surface called
>> "surface" means the lower boundary of the atmosphere. "Downward"
>> indicates a downward flux of momentum, which accelerates the lower
>> medium along the vector and the upper medium against the vector.
>> The surface downward stress is the wind stress on the surface.
>>
>> --------------------------------
>>
>> curl_of_surface_downward_stress
>>
>> The curl is a signed scalar that represents the magnitude of the
>> 2D surface wind downward stress vector field's local
>> anti-clock-wise rotation at a given point; clockwise rotation is
>> thus given as negative curl. The surface called "surface" means
>> the lower boundary of the atmosphere. "Downward" indicates a
>> downward flux of momentum, which accelerates the lower medium
>> along the vector and the upper medium against the vector. The
>> surface downward stress is the wind stress on the surface.
>>
>>
>> Best regards,
>> Bruce
>>
>>
>> ----------------------------------------------------------------------
>>
>>
>> Message: 1
>> Date: Tue, 19 Jan 2016 16:41:17 +0000
>> From: Jonathan Gregory <j.m.gregory at reading.ac.uk
>> <mailto:j.m.gregory at reading.ac.uk>>
>> To: cf-metadata at cgd.ucar.edu <mailto:cf-metadata at cgd.ucar.edu>
>> Subject: [CF-metadata] standard_names for wind stress curl, wind
>> stress divergence
>>
>> Dear Bruce
>>
>> > If there are indeed no standard_names that are appropriate,
>> I would like to suggest the following:
>> > divergence_of_surface_downward_stress
>> > curl_of_surface_downward_stress
>>
>> I don't think we have named those before and your proposals
>> look like the
>> natural choice to me. If you could provide definitions (like
>> those most
>> quantities have in the table) and canonical units that will
>> constitute a
>> proposal. People may then comment and when it seems that the
>> discussion is
>> over, if they are agreed, they'll be added to the list.
>>
>> Best wishes and thanks
>>
>> Jonathan
>>
>
>


-- 
*******************************************************
* Nan Galbraith        Information Systems Specialist *
* Upper Ocean Processes Group            Mail Stop 29 *
* Woods Hole Oceanographic Institution                *
* Woods Hole, MA 02543                 (508) 289-2444 *
*******************************************************
Received on Wed May 23 2018 - 09:27:28 BST

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