[CF-metadata] physical vs dimensional units

From: Jonathan Gregory <j.m.gregory>
Date: Thu, 14 Apr 2011 08:14:12 -0000

Dear John and Steve

I agree with Steve about this:

> On 04/13/2011 02:25 PM, John Caron wrote:
> > the point im trying to make is that it would be better to understand
> > that "mol mol-1" (canonical udunit = 1) is not the same as "m3 m-3"
> > (canonical udunit = 1).
>
> In my opinion, the distinction between "mol/mol" and "m3/m3" is better
> indicated by the name of the physical quantity being displayed rather
> than by its unit attribute.

I would say mol mol-1 and m3 m-3 are actually the same unit. But that doesn't
mean the quantities with these units are the same. Similarly,
net_downward_longwave_flux_in_air and net_downward_shortwave_flux_in_air
are not the same quantity, even though they are both in W m-2.

The udunits Unix command doesn't accept garbage garbage-1 as a valid unit,
and nor should the Java version, I think.

Best wishes

Jonathan
Received on Thu Apr 14 2011 - 02:14:12 BST