Data Resources: What is netCDF?

According to the UniData NetCDF page: "NetCDF (network Common Data Form) is an interface for array-oriented data access and a library that provides an implementation of the interface. The netCDF library also defines a machine-independent format for representing scientific data. Together, the interface, library, and format support the creation, access, and sharing of scientific data. The netCDF software was developed at the Unidata Program Center in Boulder, Colorado. The freely available source can be obtained by anonymous FTP from or from other mirror sites."

In our netCDF files, we use a convention to store time by converting a date to the number of hours or days from a particular starting point. In order to make that job easier we use the UDUNITS library from UniData. This library supports conversion of unit specifications between formatted and binary forms, arithmetic manipulation of unit specifications, and conversion of values between compatible scales of measurement.

The old Climate Diagnostics Center (now part of PSD), in cooperation with other climate data providers, produced a set of conventions that specify much of the metadata content of our netCDF files. In our later datasets and where possible, we have added additional metadata to make our files CF compliant. This means that software packages that recognize these conventions can read any and all of our files.