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Reading ECMWF grib files

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  • Subject: Reading ECMWF grib files
  • Date: Thu, 14 Dec 2006 07:48:29 -0700
Hi Xavier-

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>   I have been looking at IDV and it looks like a very promising tool
> for satellite and metorological data display. It does have more
> or less everything what I would have wished for a display tool
> (some thing still missing though). It is also nice
> to see it like an open source tool.

Thanks.

>   I have been trying to read ECMWF grib data. I have been
> successful with surface parameters, but not with the 3D fields
> (temperature). It gives several errors when reading it.
> The fields are in ECMWF sigma levels, and latlon grids. Should I really
> use fields in pressure levels? Or is there a way to read
> the sigma levels files?

What version of the IDV are you using?  What are the errors?
With version 2.0 or later, it should give you a warning that
it doesn't know how to deal with the vertical coordinate (sigma),
but still should plot the data.  

At present, the IDV only plots data with pressure or height
coordinates at the correct locations in the map box.  The vertical
scale on the box is altitude.  There is no convention for relating
sigma to height in the GRIB files.  For data in netCDF files,
we use the CF conventions to relate sigma to height.

Don Murray