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
* This standard name seems related, but it has a definition that isn't
clear to me at all:
|wind_mixing_energy_flux_into_sea_water (||W m-2):|
||'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.) In accordance with common usage in geophysical
disciplines,
"flux" implies per unit area, called "flux density" in physics.'
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>>
> 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
> Message-ID: <20160119164117.GA23893 at met.reading.ac.uk
> <mailto:20160119164117.GA23893 at met.reading.ac.uk>>
> Content-Type: text/plain; charset=us-ascii
>
> 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 16 2018 - 08:29:03 BST
