[CF-metadata] Standard names for wave model data.

From: Stark, John <john.stark>
Date: Fri, 02 Jun 2006 10:07:18 +0100

Jon,
Thanks for the comments. I agree that just 'wave' is ambiguous. I like
'ocean_surface_wave' instead.

> standard_name = "wave_spectrum_direction" ;
> standard_name = "direction_of_wave_velocity" ;
The reason for 2 directions was that one represents a coordinate
variable, and the other represents the principal wave direction (the one
associated with the peak in the energy spectrum). However, I think we
can use the 'cell_methods' here with 'wave_energy: maximum'.

>The units of m2 are not units of energy. Perhaps it's the square of
>the wave amplitude, or the RMS amplitude?
True. It is really a 'variance density spectrum' but wave modellers seem
to refer to this as an 'energy density spectrum'. A factor of (rho * g)
relates the two, so I have removed 'energy' from the name. Now I suggest
ocean_surface_wave_spectrum_density, units m^2 s-1 rad-1
and
ocean_surface_wave_frequency_spectrum_density, units m^2 s-1


The 'zero up-crossing' period is a standard means of measuring wave
period. It is defined using the time the surface height passes upward
over the mean level. Other definitions of wave periods include peak and
mean. Peak could be defined using cell_methods ('wave_energy : maximum')


So the request is now for these:

ocean_surface_wave_significant_height, units m
ocean_surface_wave_zero_upcrossing_period, units s

ocean_surface_wave_from_direction, units degrees
ocean_surface_wave_to_direction, units degrees

(Convention is for direction toward which energy travels for wave
spectra with frequency & direction, but the direction from which waves
are coming [like wind] in other contexts.)

ocean_surface_wave_spectrum_density, units m^2 s-1 rad-1
ocean_surface_wave_frequency_spectrum_density, units m^2 s-1
( Could use 'variance' in name too.)

ocean_surface_wave_frequency, units s-1 (Hz)

wind_wave_zero_upcrossing_period, units s

swell_wave_zero_upcrossing_period, units s


John


John Stark SST and Sea Ice Scientist

Met Office FitzRoy Road Exeter EX1 3PB United Kingdom

Tel: +44 (0)1392 885059 Fax: +44 (0)1392 885681
Received on Fri Jun 02 2006 - 03:07:18 BST