Dear Jonathan et al,
Thank you for taking serious consideration of the names I had proposed.
Here is a list of what I am rather certain we agree on:
* partial_pressure_of_carbon_dioxide_in_air:Pa
* partial_pressure_of_carbon_dioxide_in_sea_water:Pa
* speed_of_sound_in_sea_water:m s-1
* height_above_sea_floor:m
* volume_absorption_coefficient_of_radiation_in_sea_water:m-1
* volume_attenuation_coefficient_of_radiation_in_sea_water:m-1
* volume_scattering_function_of_radiation_in_sea_water:m-1 sr-1
* platform_pitch:degree
* platform_roll:degree
If you accept (and interpret as I do) the NIST SI Unit rules and style conventions (
http://physics.nist.gov/cuu/Units/checklist.html) #22, which mentions molality, then we also agree on the following:
* molality_of_oxygen_in_sea_water:mol kg-1
* molality_of_nitrate_in_sea_water:mol kg-1
* molality_of_phosphate_in_sea_water:mol kg-1
* molality_of_silicate_in_sea_water:mol kg-1
You had proposed "Omnidirectional spherical irradiance" for 4-pi spherical or "scalar" irradiance. The ocean optics literature tends to use the word "total", rather than "omnidirectional" to indicate a 4-pi measurement. Incidentally, such a 4-pi measurement is often the sum of upwelling and downwelling 2-pi spherical irradiances, where the difference (downwelling minus upwelling) is called "net downward", and which is already used in the CF convention.
So rather than:
omnidirectional_photosynthetic_spherical_irradiance_in_sea_water:W m-2 omnidirectional_spectral_spherical_irradiance_in_sea_water:W m-3
I would like to propose:
* total_photosynthetic_spherical_irradiance_in_sea_water:W m-2
* total_spectral_spherical_irradiance_in_sea_water:W m-3
For my proposed backscattering variable, you had suggested using just "scattering" rather than "back-scattering", and wondered if "back" was important. I would have to that "back" is indeed important, since the majority of scattering measurements are either 1)backscatter 2)small-angle forward scattering, or 3)difference of attenuation and absorption, and while any of the three measurement techniques -can- be scaled to estimate total scattering, the calculations are generally not performed because they are very approximate, and the resulting total scattering values are not comparable across techniques. Hence, I'd like to stick with:
* volume_backscattering_coefficient_of_radiation_in_sea_water:m-1
Also, you mentioned that you didn't understand the comments about being "relative to air or pure water". The issue is how 'zero' is defined, and is somewhat of a calibration issue -- "relative to air" is essentially "relative to nothing", so I prefer it.
Here is one that I have had a change of heart on and would now like to drop from the list, as it is just an intermediate value used to calculate the volume attenuation coefficient of radiation in sea water:
* volume_transmissivity_of_radiation_in_sea_water:m-1
Chris Webster had some interesting arguments regarding speed. So now I'd now like to propose:
* platform_ground_speed:m s-1 (alias for aircraft ground_speed or ship speed_over_ground)
* platform_water_speed:m s-1 (indicated = true for water craft).
You had asked if the various types of direction discussed - platform heading, true heading and course - are they all by intention the *same* quantity, ascertained by different means. I'd say not, as some platforms (satellites or ARGO drifters, for example) have a platform heading (i.e., the direction that the local coordinate system is pointed relative to the geoid, which affects the platform's viewing geometry), which is completely independent of their course. So perhaps we live with the following?
* platform_forward_angle or platform_forward_looking_angle, degrees (direction the platform is pointing, obtained from a (gyro) compass, corrected for magnetic declination)
* platform_track_angle, degrees (direction the platform is moving, obtained from global positioning, corrected for magnetic declination, alias for true_heading or course_over_ground).
You mentioned that you didn't understand why sea water bioluminescence was related to flow rate. Having spoken with the scientist that developed the bathyphotometer in question, it appears that the flow rate is mainly a QC check which can be ignored for our purposes. Also, the units should be s-1 m-3, as you suggest, but the variable name should probably mention photons, per the NIST style guide. How about:
* sea_water_bioluminescent_photon_rate:s-1 m-3
Regarding (sea_water_dissolved_oxygen_saturation:1), you wanted to know if this is the concentration as a fraction of the saturated concentration. Yes, it is.
* sea_water_dissolved_oxygen_saturation:1
Regarding (sea_water_dissolved_oxygen_volume_fraction:1), you wanted to know if this is the ratio of the volume of oxygen gas to the volume of sea water. Yes, it is (the original units are ml/l).
* sea_water_dissolved_oxygen_volume_fraction:1
Regarding (sea_water_fluorescence:1) you wondered if there was any point in this as a standard name. At this point in time, given the state of fluorometer technology, probably not.
Regarding (surface_carbon_dioxide_partial_pressure_anomaly:1), 'anomaly' indicates the difference between air and water carbon dioxide partial pressure. I see that this is different than how anomaly is used for all the other CF variables, so how about:
* surface_carbon_dioxide_partial_pressure_difference:Pa
Regarding (water_volume_transport:m3 s-1), you wondered what used this quantity for. Two purposes: 1, for measuring estuary flows. 2, for monitoring the supply of water to in-situ sensors -- if the flow rate drops, then the measurements become invalid.
* water_volume_transport:m3 s-1
Thanks again,
Mike
Received on Wed Aug 03 2005 - 12:41:27 BST
