[Met_help] Problem running Grid Stat

[John Halley Gotway]

Stefan,

I need to tell you about 3 things:

First, to answer your question about projections.  You're using an "equidistant" projection, which we assume mean "cylindrical equidistant".  That's also referred to as a Plate Carree or a Lat/Lon
projection.  In your NetCDF file, please add the following as global attributes:

:Projection = "LatLon" ;
:lat_ll_deg = "-90.000000 degrees_north" ;
:lon_ll_deg = "0.000000 degrees_east" ;
:delta_lat_deg = "1.000000 degrees" ;
:delta_lon_deg = "1.000000 degrees" ;
:Nlat = "181 grid_points" ;
:Nlon = "360 grid_points" ;

Where you ...
   - Set "lat_ll_deg" and "lon_ll_deg" to define the lower-left corner of your grid.
   - Set "delta_lat_deg" and "delta_lon_deg" to define the change in lat/lon values.
   - Set "Nlat" and "Nlon" to define the grid dimensions.
Hopefully that'll do the trick and allow MET to read these files.

Second, your forecast and observation files appear to reside on different grids.  The forecast data, aladfr_euro, is on a grid of dimension 141x99.  The observation data, veraxx, is on a grid with of
dimension 166x136.  In order to compare these files in MET, you'll need to place the gridded data on a common grid.  Unfortunately, MET doesn't provide any utilities for regridding data.  It's the
user's responsibility to do this.  The "copygb" tool may be used to regrid GRIB files, but since you're using NetCDF, that won't help you.

Third, I used the ncview utility to look at the contents of the forecast and observation file you sent.  The data looks pretty garbled.  It appears that there may be an issue in how the data is
getting packed into this NetCDF file.

Hope that helps.

John Halley Gotway
johnhg at ucar.edu

Stefan Kiesenhofer wrote:
> Dear MET Help,
> 
>  
> 
> When I run Grid-Stat I get  " NetCDF: Attribute not found".
> 
> I'm using netcdf files created by "ncgen" from CDL files. After reading the
> Met help Email archive, I tried to make my files look like the output of the
> PCP-combine tool.
> 
> The problem is I think the grid definition. Lat and Lon are computed from an
> equidistant x, y grid. Attached you can see my forecast file (aladfr_euro.)
> and my observation file (veraxx.)
> 
> How I can define my grid?
> 
>  
> 
> Thanks,
> 
>  
> 
> Stefan Kiesenhofer
> 
>  
> 
>  
> 
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 
> Department of Meteorology and Geophysics A - 1090 Vienna, 
> 
> Althanstrasse 14, UZA II
> 
>  
> 
> 
> 
> 
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