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19990909: help needed with converting grib files to GEMPAK format

>From: Emily K Grover <address@hidden>
>Organization: .
>Keywords: 199909091906.NAA07311

>To whom it may concern,
>
>I am trying to convert reanalysis grib data files into GEMPAK format. I
>have tried both nagrib and dcgrib. I suspect that my problem lies with the
>grib file's projection. The reanalysis files have a Gaussian projection.
>As far as I can tell, GEMPAK doesn't have a Gaussian projection option in
>its tables. (If I am wrong, please correct me.) Below are the error
>messages I have received.
>
>
>When I use nagrib I receive the following error message:
>
>        [NAGRIB -10]  Input for GEMPAK output file is blank.
>
>When I use dcgrib I get the following error message:
>
>       Sep 09 18:30:08 dcgrib[6054]:  Invalid center id/grid 
>       id combination: 721948pres_msl.gem
>
>
>I have already confirmed that I have the proper directory structure and
>that I have version 5.4 gempak.
>
>Any help or suggestions you can offer will be greatly appreciated. Thank
>you in advance.
>
>Emily Grover
>
>_________________________________________________________________________
>Emily K. Grover                                        MMMMMM     MMMMMM
>University of Michigan                           MMMMM     MMMMM
>Atmospheric, Oceanic, and Space Sciences         MMMMMM   MMMMMM
>Mesoscale Meteorology Laboratory                 MMMMMMM MMMMMMM 
>734.764.0564                                     MMMM MMMMM MMMM
>                                                 MMMM  MMM  MMMM
>                                                MMMM       MMMM
>                                               MMMMMM     MMMMMM
>_________________________________________________________________________
>
>
>


Emily,

Your assumption is correct. GEMPAK is not capable of handling variable
spaced grids. The Gaussian grid format varies the grid row spacing
in the latitudinal direction. All of the Gempak grid functions expect
a rectangular grid.

In order to convert the data into Gempak format for display, you would need
to interpolate the data to a regularly spaced grid (eg CED projection).

Steve Chiswell