HF radar role in an integrated ocean observing system

The Australian Coastal Ocean radar Network (ACORN) is a monitoring network of HF radars which are being installed around Australia under a National Collaborative Research Infrastructure Strategy (NCRIS). It is a five-year project, at the end of which there will be five pairs of radar stations and one triplet installed and operating, enabled by the central pool of funding for the Integrated Marine Observing System (IMOS) which is a part of NCRIS, and augmented by funding from other sources. At each chosen site there is a pair (or triplet) of radar stations, mounted on the shore, which receive radar echoes from the rough sea. The two stations provide a triangulation which enables the data analysis software to extract surface currents, wave heights and directional wave spectra over the coastal ocean. The NCRIS strategy is to support research into coastal dynamics and exchange between the open ocean and the continental shelf. Research is being undertaken into the use of maps of surface currents, well resolved in time and space, in mixing of different bodies of water, physical connectivity between reefs and islands, and nowcasting and short-term forecasting of surface currents. There is potential for application of the data to management of coastal marine resources, and in marine safety areas. Real-time maps of surface currents and the prospect of short-term forecasting have the potential to reduce search areas in coastal waters and to make pollution/spill mitigation more effective. With the establishment of HF radar monitoring stations like those in ACORN, there is growing opportunity for researchers around the world to access data from well curated archives to carry out basic research on physical oceanography, or applications research without having direct access to the measuring facility. One of the features of IMOS is to establish such an archive which is easy to access and free to research users. This feature brings the ACORN HF radars into GEOSS for coastal process- es and dynamics.