The Importance of High-Frequency Radar for Search and Rescue at Sea: A Foundation for a National Network for the Integrated Ocean Observing System

U.S. Coast Guard search and rescue (SAR) missions require environmental information (winds, waves, and surface drift) to plan operations focused on saving lives and aiding those in distress. SAR is one of the six central operational missions for the U.S. Coast Guard where they respond to approximately 16,000 cases each year. The collected environmental information is also used to organize marine protection efforts such as predicting fate and transport of oil spills and other hazardous discharges. SAR planning, until 2005, was based on atmospheric wind drift combined with tidal predictions near the coast to inform SAR response. Over the last decade, there has been significant development utilizing surface current measurements from high-frequency radar (HFR) systems to improve SAR efficacy. In the Mid-Atlantic Bight, an HFR network was deployed and operated from 2007 to present making hourly measurements of sea surface currents in the Mid-Atlantic Bight. Several studies have shown that HFR in the Mid-Atlantic was able to reduce search areas by 66% compared with global models. HFR data are also assimilated into a range of models to provide forecast products. Based on data provided by the U.S. Coast Guard, products that assimilate HFR are the most requested product with 37 average daily requests. Incorporating HFR data into SAR planning has proven to significantly improve accuracy and efficiency, making it a critical and frequently requested tool for the U.S. Coast Guard's environmental monitoring and rescue operations. The HFR network in the Mid-Atlantic is reaching 20 years of operation, with some stations reaching 25 years of service life. The focus of this paper was to take assessment of the status of the network and discuss how the data have been used by the U.S. Coast Guard for SAR justifying reinvestment in the network. This observational design provides a useful deliverable to key marine stakeholders that could be adopted internationally. The data stream and forecasts provide a safer environment for the mariner if trouble strikes, leading to a stronger and more prosperous maritime economy.