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[IDV #ZBV-533582]: IDV - ECMWF GRIB fields - unknown units for Z/PV

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  • Subject: [IDV #ZBV-533582]: IDV - ECMWF GRIB fields - unknown units for Z/PV
  • Date: Mon, 08 Jan 2007 12:25:24 -0700
HP-

> Institution: EUMETSAT
> Package Version: 2.2b1
> Operating System: Windows XP
> Hardware Information: Java: home: C:\\Program Files\\IDV_2.2b1\\jre version: 
> 1.5.0_06 j3d:1.3.2 fcs (build12)
> Inquiry: Hi
> 
> IDV reports "unknown unit" with for the geopotential and potential vorticity 
> when reading
> them off GRIB files retrieved from the ECMWF archive. Up to know I used such 
> data rather
> rarely and got around by adapting to the data as is. However, now that other 
> EUMETSAT
> people will start to use IDV (and also for my own convenience) it would be 
> nice to have this
> issue settled.

Okay.  I thought this had been fixed at the table level, but not.  I've
fixed it and the fix will be in tomorrow's build (which now runs at 
8-9Z).

FYI, the problem is that the grib tables specify the units with a +
in the exponent:

K m+2 kg-1 s-1

which we were not handling.  In reality, the + is not really
standard and I'm going to see if Robb will change the tables.


> I attach a sample file with data from a single time slot and level. As you 
> will see parameters
> other than geopotential and PV are to the liking of IDV.
> 
> By and by I have to revise my naive idea of GRIB being straightforward!

It all depends on the decoding. ;-)

Thanks for finding this.

Don

Ticket Details
===================
Ticket ID: ZBV-533582
Department: Support IDV
Priority: Normal
Status: Open