Rotated poles, HIRLAM GRIB and GrADS

[Tero Siili]

Dear GrADS users and developers,

my colleagues and I are using a mesoscale model (based on the HIRLAM
NWP model), which has the option of a rotated pole. This information
is apparently stored in the GRIB-format output files.

To put it simply: does GrADS know how to display - and if necessary,
INTERNALLY convert the coordinates and wind vectors & interpolate to
natural lat/lon coordinates - such data sets with arbitrary rotated
pole(s)? The PDEF keyword available for .ctl files seems like a
potential way to handle this, but is the PDEF versatile and flexible
enough - or constrained to a fixed set of coordinate transformations?
If PDEF can be used for this type of data transformation, could
someone perhaps provide an example of how to define the PDEF field in
the .ctl file? We are currently using GrADS version 1.9b4.

A colleague of mine found a couple of external, standalone tools
(xconv and convsh) which may help, but info on both GrADS'
capabilities (or lack thereof) as well as on other useful conversion
tools would be highly helpful.

With best regards and looking forward to hearing more about this,


Tero Siili
SOHO Science Operations Coordinator
European Space Agency, c/o NASA Goddard Space Flight Center, Mailcode
612.5
Greenbelt MD 20771, United States of America

Tel/EAF: +1 301 2869028
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