NetCDF Status

Ed Hartnett, Russ Rew
July 2, 2007

NetCDF and Unidata

Work in maintaining, supporting, and developing the netCDF data model and software is associated with Endeavor 6: Improved scientific data access infrastructure from the Unidata 2008 proposal. NetCDF has become a key infrastructure element for data providers and users of oceanographic and atmospheric science data, as well as data in other geosciences.

Recent netCDF development aims at generalizing the netCDF data model, improving interoperability with other representations for scientific data, making the netCDF interface more suitable for use on high-end parallel platforms with high-resolution models, and providing netCDF software on a wider range of platforms.

libcf - The CF Conventions Library

The NetCDF CF Library supports the creation of scientific data files conforming to the Climate and Forecast (CF) conventions, using the netCDF API. It assists users in correctly writing and interpreting data conforming to CF conventions.

We have established a nightly testing and snapshot distribution of libcf, linked from the libcf web page, that acts as the alpha release of the software. A general, simple, geographic subsetting capability has recently been added to libcf.

Ed Hartnett presented a talk on the libcf library at the Sixth GO-ESSP (Global Organization for Earth System Science Portal) workshop in June. Workshop attendees expressed interest and enthusiasm for the continued development of libcf and agreed on the desirability of supporting a new CF proposal (Gridspec) within libcf.

NetCDF-4/HDF5 Development

NetCDF-4, the next major upgrade to netCDF, uses the HDF5 format to read and write data files through the netCDF API. This allows the introduction of many new features, including compression, parallel I/O, groups, user-defined data types, and more. NetCDF-4.0 depends on HDF5 version 1.8.0, which is currently in beta release.

The netCDF-4.0-beta1 has been available since April, 2007. The netCDF-4 snapshot page has links to the latest version.

Russ Rew presented a talk on the development of CF conventions for netCDF-4 to participants in the GO-ESSP Workshop in June.

Seminar on Best Practices

In June John Caron and Russ Rew presented a webcast seminar on "Writing NetCDF Files: Best Practices". The seminar was well attended and had about 20 remote participants.

NetCDF Training Workshop

The "NetCDF for Developers and Data Providers" training workshop on July 20 will be large, with over 40 registered participants, presentations by Russ and Ed, and short talks by two invited speakers on parallel netCDF and HDF5.

Other NetCDF Developments

A new C++ API is under development by Shanna Shaye Forbes, a returning SOARS protegé. Last summer Shanna designed the new C++ API and implemented a prototype. This summer she is completing the prototype. In addition to taking advantage of C++ features standardized since the current C++ API was developed, it also supports the new netCDF-4 features.

Strategic Planning Notes

During the next five years, Unidata should

by Russ Rew