NetCDF 4.4.1

Version 4.4.1 of the NetCDF-C library is now available. This release provides official support for libhdf5 1.10.0.

Note: netCDF library 4.4.0 or earlier, combined with libhdf5 1.10.0 or greater, will generate netCDF-4 format files that cannot be read by software using earlier versions of libhdf5 (1.8.x), regardless of the version of netCDF.

Note: As documented, netCDF-4 format support requires a minimum hdf5 library version of 1.8.9.

Note: NetCDF-3 format files are not affected by this issue. NetCDF-3 files remain forward and backward compatible through all netCDF library versions 3.x through 4.x.

Additional highlights of this release beyond support for libhdf5 version 1.10.0 include:

• Modified nc_inq_type() so that it would work more broadly without requiring a valid ncid.
• Speedier var and dim retrieval in nc3 files.
• Added provenance information to files created. This information consists of a persistent attribute named _NCProperties plus two computed attributes, _IsNetcdf4 and _SuperblockVersion.
• Starting with release 4.4.1, netCDF-4 files will have superblock version 0 instead of superblock version 2, as in previous netCDF versions. This is due to a workaround required to avoid backward read and write incompatibility when using libhdf5 1.10.x or greater. Superblock versions 0 and 2 appear to be forward- and backward-compatible for both reading and writing. Superblock 1 files made by direct HDF5 applications are hypothetically also compatible, but this is not yet confirmed. Other than a different superblock number, all user data and metadata should remain consistent.
• Bug fixes and build process enhancements.

Detailed information about the release is available in the Release Notes.

Complete information about using this release can be found in the NetCDF Documentation.

Source-code zip and tar.gz archives can be found on Unidata's NetCDF-C GitHub site.

Pre-built Windows binaries for use with Visual Studio) are available from this page.

Users of the netCDF FORTRAN and C++ Libraries Note

You can use the upgraded C library without upgrading your FORTRAN or C++ library.