[CF-metadata] dimensionless vertical coordinates

From: Yilmaz Arslanoglu <yilmaz.arslanoglu>
Date: Fri, 11 Mar 2011 16:55:40 +0100

Hi;

I was wondering the following points regarding dimensionless vertical
coordinates:

1) Assume that we have a variable U (let's say ocean current eastward)
and is defined on a dimensionless vertical coordinate (for example
ocean-s coordinate).
    Do the variables indicated in "formula_terms" of this vertical
coordinate need to share exactly the same longitude and latitude
coordinates (possibly auxiliary) with
    the main variable U, or can they be defined over their own
longitude and latitude coordinates independently?

2) Just given the "positive" attribute and the information whether the
sigma coordinate is monotonically increasing or decreasing, is it
possible to
    conclude that the array of z values z(sigma, t, x, y) are always
increasing or decreasing? That is, is it possible to make the
following conclusion
    for any dimensionless vertical coordinate ? ( sigma here is just
an example )

    I was actually wondering what will the "positive" attribute
exactly mean for a sigma coordinate.


     Sigma Positive Z
     --------- ------------ --------------
     increasing down increasing
     increasing up decreasing
     decreasing down decreasing
     decreasing up increasing



Best regards,
Yilmaz
Received on Fri Mar 11 2011 - 08:55:40 GMT