[CF-metadata] standard name proposals

From: Jonathan Gregory <j.m.gregory>
Date: Wed, 6 Aug 2003 17:28:06 +0100

Dear John

> If the packed data was in the 1024-1028
> range, then having an add_offset of -1000 would make the unpacked data
> technically not agree with the units?

No, I don't think so. Most units don't have an implicit "origin". The units
of kg m-3 are unchanged by subtracting 1000 kg m-3.

> Maybe this would just be a good place
> for the "comment" attribute?

I think we do need to record the 1000 in a standardised attribute. add_offset
seems the best choice to me. I wonder if Brian has a view. It is intended
really for packing, but it is functionally what you want to do.

> "E" is short for einsteins,
> which I guess is an old unit of measurement. And "einsteins" isn't even
> accepted by udunits (it interpreted "E" as 1e+18 instead!!!) The correct
> unit would be "moles", making the full unit specification as
> "micromoles/m^2/s.

Ah, I see. In that case it must be talking about moles of photons, I suppose,
and there must be an assumed frequency for conversion to radiative flux. I
don't think we can call a quantity in mol/m2/s a plain "radiative_flux", and
"radiation" is too vague. Is there any other conventional name for a radiative
flux expressed as a flux of photons?

> As for the 2nd part, good question, it would appear to be both in our case, as
> we measure this both at the surface and at various depths in the water
> column.

We can have both then, when we've decided on the basic term.

Cheers

Jonathan
Received on Wed Aug 06 2003 - 10:28:06 BST