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>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