Re: [bufrtables] More on table versions

Hi Milan,

I am not sure what happened with the descriptor 022039. But I noticed that this entry, with ref=3D-5000, scale=3D3 and 12bits, cannot handle the "meteorological residue of tidal elevation". The value of residue can be positive or negative (see attached example). If ref=3D-5000 and scale=3D3, 12bits data width can only describe data ranging from -5m to -0.906m. 13bits would allow a range from -5m to 3.19m. The person who made the Note(4) may know this problem and suggested to use entry 022040, which got 14bits. Kelvin who is in Geneva this week (ET-IO meeting) might be able to tell more about the history of this entry.

Cheers,

Weiqing

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Dr. Weiqing Qu                 ,-_|\   Phone: +61 3 9669 4236
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From: Milan Dragosavac [mailto:Milan.Dragosavac@xxxxxxxxx]
Sent: Fri 19/09/2008 18:58
To: John Caron
Subject: Re: [bufrtables] More on table versions



Dear Jeff and John,

Thanks for point out 022039 difference. I checked all versions of the
tables I have and the result is  3 -5000 and 12 bits data width.
However, WMO version 13 introduced change to 13 bits which I can not
recall why. In the same time there is a Note(4) which state to use
022040 instead of 022039. the entry 022040 got 14 bits data width.
Obviously there is a conflict. I believe 13 should be set back in the
version 13 to 12 bits. I would like Weiqing to comment on this since
they produce tide data.

Best regards

Milan
Milan Dragosavac

ECMWF
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