The data if available on spectral grid or gaussian grid, then it needs to be remapped onto a regular lat lon grid, so that it can be analysed using Met.3D. The following code snippet outlines the steps to do this provides a minimal example to perform the remapping.
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#!/bin/bash ##################################################################################### # Minimal examples of basic CDO commands for remapping ERA5 data ononto a regular grid # which can be loaded into Met.3D for interactive 3-D visual analysis # # (Marcel Meyer, Visual Data Analysis, Regional Computing Center, UHH, 2020) # # # Link to the Met.3D documentation # https://collaboration.cen.uni-hamburg.de/display/Met3D/Welcome+to+Met.3D # # Link to the cdo documentation # https://code.mpimet.mpg.de/projects/cdo/wiki/Cdo#Documentation # # Link to a cdo reference sheet # https://code.mpimet.mpg.de/projects/cdo/embedded/cdo_refcard.pdf # ##################################################################################### ########### # define path to the folder storing the ERA5 data as provided by the ECMWF # (GRIB data with spatial coordinate systems "Gaussian Grid" or "Spherical Harmonics") DATAFOLDER=/path/to/ERA5-data-folder/ ########## # define path to the folder for storing the remapped ERA5 data-files POSTPROCESSEDDATAFOLDER=/path/to/Results-Folder/ mkdir -p ${POSTPROCESSEDDATAFOLDER} ########## # define path to a file characterizing the grid to which the ERA5 data will be remapped TARGETGRIDFILE=/path/to/targetgridfile.txt # See below for an examplar gridFile for remapping with CDO to a regular lat-lon grid : # --> "cdo_gridFile_regular_LatLon_minimalExample.txt" ########## # define input and output data files INFILE=/path/to/ERA5_Data_File OUTFILE=/path/to/ERA5_Data_on_regular_grid ########## # bilinear remapping from reduced Gaussian grid to regular Lat-Lon grid # and conversion from GRIB to NETCDF cdo -f nc4 -remapbil,${TARGETGRIDFILE} -setgridtype,regular ${OUTFILE} ${INFILE} ########## # bilinear remapping from spectral grid to Gaussian grid to regular Lat-Lon grid cdo -f nc4 -remapbil,${TARGETGRIDFILE} -sp2gpl ${INFILE} ${OUTFILE} |
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