[CF-metadata] water level with/without datum

From: Jonathan Gregory <j.m.gregory>
Date: Sat, 13 Feb 2010 09:00:05 +0000

Dear John

Sorry not to be clear. My main point is that sea_surface_height is an existing
term which is customarily used to refer to the level of the water surface in
the open ocean. I am arguing that, at the coast, the level of the sea water
surface is really the same quantity as sea_surface_height away from the coast,
and so it should have the same name.

Then that raises the question of what to call the level of the water surface
when it is a lake or a river but not the sea. We could have standard names
using the phrases lake_surface_height and river_surface_height. That would be
fine, except that the distinction may in some cases become inconvenient and
arbitrary, as you have to decide exactly when it is one or another. It would
be convenient to use the same word for all of them.

I don't think it's such a good idea to solve this by dropping "sea" and calling
it just "water". Although you are right that the exact term water_level
might not be needed in the atmosphere and the ground (though I suppose
something like it might be used for ground water), I think it is preferable to
use a term which includes the context. We try to make the standard names as
informative and self-explanatory as we can, so we don't use just the word
"water" without indicating somehow where the water is in the Earth system.
For instance, we do not have a standard name of "water content" because the
context is not clear. We have names such as atmosphere_water_content and
soil_frozen_water_content.

Best wishes

Jonathan
Received on Sat Feb 13 2010 - 02:00:05 GMT