CM SAF: CDO
CM SAF’s climate monitoring products are provided as HDF5 (Hierarchical Data Format, release 5). Reasons for selecting this data format were its high compression efficiency and the features to include several data models and self-describing datasets. As many users are interested to receive the data in different formats or projections, CM SAF has supported the integration of its data formats into the “climate data operators”. The “climate data operators” (CDO) are a collection of command line operators that were originally developed for processing and analysis of data produced by climate and numerical weather prediction models (e.g. for file operations, simple statistics, arithmetics, interpolation or the calculation of climate indices). Supported file formats are NetCDF, GRIB and several binary formats.
The package was developed at the Max-Planck-Institute for Meteorology and is therefore also available on their web page (https://code.zmaw.de/projects/cdo). With installations in more than 150 groups world-wide, the package is widely established in the climate modelling community. It is typically used in a UNIX/Linux environment.
Processing CM SAF data with CDO
Besides the pure conversion of CM SAF HDF5-files to other formats, the package also offers opportunities for interpolation to other grid types, selection of regions, etc. Daily and monthly mean products of CM SAF are provided in equal-area projections that are described in the metadata entries of the HDF5-files. CDO employs this information for spatial operations on these final products. Processing of CM SAF intermediate products on original pixel-resolution is also facilitated when pixel-related geolocation is available (for geostationary as well as polar-orbiting satellites satellites).
Example scripts and data on the use of CDO, including the conversion of the CM SAF hdf-files into netcdf, the extraction of selected regions and the regridding of data, e.g., onto a regular lon-lat grid, can be downloaded here. These scripts are designed to operate on MS Windows. For Linux/Unix operation systems only small modifications are required
The usage of this tool is at your own risk.
MW / Apr2017