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ERA40 Grads binary converted to netCDf has wrong vertical axis

Added by Rene Hommel over 12 years ago

Hi,

don't know whether a problem like this was posted already: With CDOs I converted a three-dimensional Grads binary (ERA40) to netCDF. This file contains the geopotential and after conversion this geopotential is largest at the lowest level and vise versa. I checked the Grads binary and there everything looks fine.

For conversion I used a syntax I found in the CDO wiki:

cdo -f nc import_binary era40.ctl era40.nc

Can someone help me what that?

Thanks

Rene


Replies (3)

RE: ERA40 Grads binary converted to netCDf has wrong vertical axis - Added by Uwe Schulzweida over 12 years ago

Hi Rene,

I can't reproduce this problem. Could you please attach your binary and ctl file?

Cheers,
Uwe

RE: ERA40 Grads binary converted to netCDf has wrong vertical axis - Added by Rene Hommel over 12 years ago

The data were produced by Manu Anna Thomas, which was at MPIm a while ago. She told me that in the CTL file (attached) the entry/line "OPTIONS ZREV" indicates that the levels have to be interpreted by Grads vice versa. I assume CDOs did not consider this when I converted the Grads binary to netCDF. Files are large, almost 500MB. Can put them at the ZMAW FTP server.

gp_data.ctl (304 Bytes) gp_data.ctl

RE: ERA40 Grads binary converted to netCDf has wrong vertical axis - Added by Uwe Schulzweida over 12 years ago

Yes, thats right, the OPTION ZREV was not considered correctly. I have fixed this problem for the next CDO release.

    (1-3/3)