Dear Andy
Thanks for your posting. You're doing it just right!
Both of your proposals have the form
sea_surface_height_above_mean_sea_level_due_to_X
and I wonder, do you really mean above MSL in *both* cases? Storm surge is
usually measured wrt the current tidal level - isn't it? Also, it seems to me
that "due to" isn't quite right in this case. To quote from the definitions:
"due_to_process" means that the quantity named is a single term in a sum of
terms which together compose the general quantity named by omitting the phrase.
Most "due_to" names go with things which are processes that change the state,
or they are rates of change. SSH is a state, I would say. For example, my mass
*itself* isn't due to my eating too many biscuits, or due to my running a
half-marathon - it's an aspect of my state. It's the *changes* in my mass which
are due to those separate things, that can be added up.
I wonder whether, at least in the case of storm surge, you mean the difference
between SSH with and without the storm surge. Although "sea surface elevation"
is often used as a synonym for SSH, maybe we could make use of it in the sense
of "how much *higher* the sea surface is" due to the storm surge, which is the
concept sometimes called "setup", but that's jargon, and I wouldn't advocate it
for a CF standard name. Would
sea_surface_elevation_due_to_storm_surge
be OK, I wonder? That quantity isn't wrt MSL or geoid or any other fixed
surface; it's the difference between two values of SSH. Another possibility is
change_in_sea_surface_height_due_to_storm_surge
which could be better because it's more explicit, but I'm not sure it's quite
right, because it sounds like watching the SSH going up over a certain time
interval, rather than comparing two situations with and without surge. Is this
what you mean?
For the tide, do you definitely mean the current tidal elevation wrt MSL?
I hope I haven't missed the point.
Best wishes
Jonathan
----- Forwarded message from "Saulter, Andrew" <andrew.saulter at metoffice.gov.uk> -----
> Date: Wed, 4 Apr 2018 16:13:18 +0000
> From: "Saulter, Andrew" <andrew.saulter at metoffice.gov.uk>
> To: "cf-metadata at cgd.ucar.edu" <cf-metadata at cgd.ucar.edu>
> Subject: [CF-metadata] proposed new standard name for storm surge residual
>
> Dear all,
>
> First posting to this list, so please forgive me if I'm doing it wrong...
>
> I'd like to request an addition to the standard name list to include storm surge residual and tide. These variables are generated for the purpose of coastal flood prediction and will be available in future, netCDF based, operational products from the Met Office.
>
> Proposed standard name: sea_surface_height_above_mean_sea_level_due_to_storm_surge
> Units: m
> "Sea surface height" is a time-varying quantity. "Height_above_X" means the vertical distance above the named surface X. "Mean sea level" means the time mean of sea surface elevation at a given location over an arbitrary period sufficient to eliminate the tidal signals. The specification of a physical process by the phrase "due_to_process" means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. Storm surge effects, due to meteorological forcing of the ocean and interaction between the generated surge and tides, are a significant contributor to the observed sea surface height.
>
> Proposed standard name: sea_surface_height_above_mean_sea_level_due_to_tide
> Units: m
> "Sea surface height" is a time-varying quantity. "Height_above_X" means the vertical distance above the named surface X. "Mean sea level" means the time mean of sea surface elevation at a given location over an arbitrary period sufficient to eliminate the tidal signals. The specification of a physical process by the phrase "due_to_process" means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. Tides are a significant contributor to the observed sea surface height; here "tide" denotes a generic variable describing the time varying tidal signal, for example as generated based on a summation of harmonically analysed components, or resulting from the application of such components as boundary conditions to a numerical tidal model.
>
> Many thanks
> Andy
>
>
> Andy Saulter
> Surge, Waves and Metocean Projects Manager
> Met Office FitzRoy Road Exeter Devon EX1 3PB
> Tel: +44 (0)1392 884703 Fax: +44 (0)1392 885681
> andrew.saulter at metoffice.gov.uk http://www.metoffice.gov.uk
>
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----- End forwarded message -----
Received on Fri Apr 06 2018 - 06:42:42 BST
