OzFlux is part of the Australian Terrestrial Ecosystem Research Network (TERN). The OzFlux network consists of nearly 30 flux towers in Australia and New Zealand, many of which are also members of the Australian Supersite Network (ASN). OzFlux is also a member of the global FluxNet community of over 500 flux stations that is designed to provide continuous, long-term micrometeorological measurements to monitor the state of ecosystems globally. The OzFlux purpose is (1) to understand mechanisms controlling exchanges of carbon, water vapour and energy between terrestrial ecosystems and the atmosphere over a range of time and space scales, (2) to provide data on carbon and water balances of key ecosystems for model testing to provide information to validate estimates of net primary productivity, evaporation, and energy absorption using remotely sensed radiance data, (3) to provide data to validate new developments in micrometeorological theory for fluxes and air flows in complex terrain, and (4) to provide high precision CO2 concentrations measurements (at Cape Grim) for use in regional, continental and global atmospheric inverse studies of the carbon cycle. Data from the OzFlux network of flux towers is available from this portal. The data is organised into collections with each collection representing at least one site.