Re: Problems opening 3D data with eta-levels

• To: Heiko Klein <Heiko.Klein@xxxxxx>
• Subject: Re: Problems opening 3D data with eta-levels
• From: Don Murray <dmurray@xxxxxxxxxxxxxxxx>
• Date: Thu, 12 Oct 2006 08:07:58 -0600

Hi Heiko-

Heiko Klein wrote:

I'm trying to open 3D+t data with the following dimension:

        float i(i) ;
                i:coord_axis = "x" ;
                i:long_name = "EMEP grid x coordinate" ;
                i:units = "km" ;
        float j(j) ;
                j:coord_axis = "y" ;
                j:long_name = "EMEP grid y coordinate" ;
                j:units = "km" ;
        float k(k) ;
                k:coord_alias = "level" ;
                k:long_name = "vertical eta coordinates" ;
                k:units = "eta_level" ;
                k:positive = "down" ;
        int time(time) ;
                time:long_name = "time at middle of period" ;
                time:units = "seconds since 1970-1-1 00:00:00.0 +00:00" ;

I'm assuming that you also have lat(j,i) and lon(j,i) in the file
or some sort of projection specification?

When trying to open this data, I get a error:
ControlDescriptor.Creating display
Real: Unit "null" must be convertable with Type default Unit "m"

The units of k (eta_level) is not a valid unit specification.
Try using "".  Also, which version of the IDV are you using?

I would like to see the different levels, either by entering the forumular to calculate the actual height via the pressure, or by just numbering the levels from 1-20. What would be the best way?

Starting with version 2.0, the IDV should handle unknown
vertical coordinates by scaling the values to altitude.
So, if you have values of k from 1-20, it will scale them
to 1-20 m.  You can use the vertical scale widget in the
display to set the vertical range of the box to be 1-20 m
and you will see the levels displayed at their appropriate
positions in the vertical.

If setting the vertical unit doesn't fix the problem, could
you send a sample file to support-idv@xxxxxxxxxxxxxxxx?

Don
*************************************************************
Don Murray                               UCAR Unidata Program
dmurray@xxxxxxxxxxxxxxxx                        P.O. Box 3000
(303) 497-8628                              Boulder, CO 80307
http://www.unidata.ucar.edu/staff/donm
*************************************************************

• References:
  • Problems opening 3D data with eta-levels
    • From: Heiko Klein