NetCDF

NetCDF, short for Network Common Data Form, is a set of data formats, libraries, and software designed for array-oriented scientific data. It provides a self-describing, portable binary format for storing multi-dimensional arrays and their metadata, enabling data exchange across different platforms and programming languages. The NetCDF ecosystem began with the NetCDF-3 classic format and has evolved to NetCDF-4, which is built on the HDF5 data model and adds new capabilities while maintaining compatibility with existing NetCDF data.

The NetCDF data model comprises dimensions, variables, and attributes. In NetCDF-3, a file contains named dimensions, variables that reference these dimensions, and attributes that describe the data. NetCDF-4 introduces a more flexible model with groups, unlimited dimensions, and richer data types, and enables features such as chunked storage and compression when used with the HDF5 back-end. NetCDF data are typically stored in .nc files.

NetCDF is supported by a family of libraries, including NetCDF-C, NetCDF-Fortran, NetCDF-C++, and NetCDF-Java. Language bindings exist for Python (netCDF4 and xarray), R, and other environments. The format is widely used in earth system science, meteorology, and oceanography, often in conjunction with the CF metadata conventions to describe variables, coordinates, units, and calendar systems. NetCDF remains an open, community-driven standard maintained by Unidata, with a broad ecosystem of tools for data creation, processing, visualization, and analysis.