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Convert COSMO-DE data from rotated to latlon grid

Added by Artur Kubik about 8 years ago

Hi,

I have a *.nc-file from the DWD, which needs to be transformed from a rotated grid to a lat lon grid. The data is forecast data for VMAX_10M from COSMO-DE model.
I have already tried different cdo-commands but so far with no good result. I tried following commands:

  • cdo setgridtype,lonlat ifile ofile
  • cdo remapbil,mygrid ifile ofile
  • cdo setgridtype,curvilinear ifile ofile

With the last one I got the output file “result4.nc”. It is a lat lon grid now, but xinc and yinc are 1 degree instead of 0.025 degree.
The grid description should probably be as attached in the file mygrid.txt. Also attached is the input file “lfff00060000.nc".

Can anybody help please?

Thanks!

Artur

Download all files
mygrid.txt (296 Bytes) mygrid.txt
lfff00060000.nc (767 KB) lfff00060000.nc
result4.nc (8.15 MB) result4.nc

Replies (6)

RE: Convert COSMO-DE data from rotated to latlon grid - Added by Ralf Mueller about 8 years ago

Hi Artur!

I used lfff00060000.nc as input an checked remapping with

% cdo remapbil,mygrid.txt lfff00060000.nc t.nc
% cdo remapycon,mygrid.txt lfff00060000.nc t_con.nc

Both commands ran without issues (results uploaded). For comparison I plotted the original data and both results.

original
bilinear
conservarive

do this look ok? I used the latest 1.7.2 release .

hth
ralf

Download all files
t_con.nc (767 KB) t_con.nc
t.nc (767 KB) t.nc
VMAX_10M_inremapbil.png (150 KB) VMAX_10M_inremapbil.png
VMAX_10M_in_lfff00060000_original.png (195 KB) VMAX_10M_in_lfff00060000_original.png
VMAX_10M_in_remapycon.png (148 KB) VMAX_10M_in_remapycon.png

RE: Convert COSMO-DE data from rotated to latlon grid - Added by Artur Kubik about 8 years ago

Hi Ralf,

yeah it looks better than my tests, thank you! But unfortunately the east of Germany is missing.
I think the original COSMO-DE data covers all of Germany and a little bit beyond.
Like shown here: http://www.cosmo-model.org/content/tasks/operational/dwd/default_de.htm

This should be the same domain, right?
Maybe the mygrid file is wrong?

Artur

RE: Convert COSMO-DE data from rotated to latlon grid - Added by Ralf Mueller about 8 years ago

IMO this is due to missing locations in your mygrid.txt. Change it and rerun the commands - this should do it.

RE: Convert COSMO-DE data from rotated to latlon grid - Added by Ashwin D almost 6 years ago

I am a bit late to this thread but I have the same issue. I need to convert COSMO rotated lat lon grid data to a lat lon grid for plotting purposes. My only question is in the remapping part - should we not first convert to a geographical projection first and then convert to a lat lon grid or does CDO does that automatically for us ?

RE: Convert COSMO-DE data from rotated to latlon grid - Added by Ashwin D almost 6 years ago

Ashwin D wrote:

I am a bit late to this thread but I have the same issue. I need to convert COSMO rotated lat lon grid data to a lat lon grid for plotting purposes. My only question is in the remapping part - should we not first convert to a geographical projection and then convert to a lat lon grid or does CDO does that automatically for us ?

RE: Convert COSMO-DE data from rotated to latlon grid - Added by Uwe Schulzweida almost 6 years ago

The remapping in CDO does that automatically for rotated lon/lat grids.

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