Uncrewed Surface Vehicles in the Global Ocean Observing System: A New Frontier for observing and monitoring at the air-sea interface

Ruth G Patterson ^1,2* Joana Beja ³ Meghan F. Cronin ⁴ Johan Edholm ⁵ Jason McKenna ⁶ Jaime Beth Palter ⁷ Alex Parker ⁸ Sebastiaan Swart ^5,9 Charles Izuma Addey ¹⁰ Wieter Boone ³ Paban Bhuyan ¹¹ Justin James Henry Buck ¹² Eugene Francis Burger ⁴ James Burris ¹² Lionel Camus ¹³ Brad DeYoung ¹⁴ Marcel Du Plessis ⁵ Mike Flanigan ¹⁵ Gregory R. Foltz ¹⁶ Sarah T. Gille ¹⁷ Laurent Grare ¹⁷ Jeff Hansen ¹⁸ Lars Robert Hole ¹⁹ Makio Honda ²⁰ Verena Hormann ¹⁷ Catherine Kohlman ²¹ Naoko Kosaka ²² Carey Kuhn ²³ Luc Lenain ¹⁷ Lev Looney ^16,24,25 Andreas Marouchos ²⁶ Elizabeth K McGeorge ^27,4 Clive Reginald McMahon ²⁸ Satoshi Mitarai ²⁹ Calvin Mordy ⁵ Akira Nagano ²⁰ Sarah Anne Nicholson ³⁰ Sarah Nickford ⁷ Kevin M. O'Brien ^27,4 David Peddie ³¹ Leandro Ponsoni ³ Virginie Ramasco ³² Nick Rozenauers ³³ Elizabeth Siddle ³⁴ Cheyenne Stienbarger ³⁵ Adrienne J Sutton ⁴ Noriko Tada ²⁰ Jim Thomson ³⁶ Iwao Ueki ²⁰ Lisan Yu ³⁷ Chidong Zhang ⁴ Dongxiao Zhang ⁴

• ¹ Elysium EPL, Darwin, Australia
• ² Charles Darwin University, Darwin, Northern Territory, Australia
• ³ Flanders Marine Institute, Ostend, Belgium
• ⁴ Pacific Marine Environmental Laboratory, National Oceanic and Atmospheric Administration (NOAA), Seattle, Washington, United States
• ⁵ Department of Marine Sciences, Faculty of Science, University of Gothenburg, Gothenburg, Sweden
• ⁶ Roger F. Wicker Centre for Ocean Enterprise, The University of Southern Mississippi, Gulfport, MS, United States
• ⁷ Graduate School of Oceanography, University of Rhode Island, Narragansett, Rhode Island, United States
• ⁸ Astraeus Ocean Systems, Bellingham, WA, United States
• ⁹ Department of Oceanography, Faculty of Science, University of Cape Town, Cape Town, Western Cape, South Africa
• ¹⁰ Center for Microbial Oceanography, University of Hawaii at Manoa, Honolulu, Hawaii, United States
• ¹¹ Department of Marine Sciences, University of Connecticut, Groton, CT, United States
• ¹² National Oceanography Centre, University of Southampton, Southampton, England, United Kingdom
• ¹³ Akvaplan-niva, Digital Solutions, Oslo, Norway
• ¹⁴ Canadian Integrated Ocean Observing System (CIOOS), Victoria, BC, Canada
• ¹⁵ Seasatellites ("Seasats"), San Diego, United States
• ¹⁶ Atlantic Oceanographic and Meteorological Laboratory (NOAA), Miami, Florida, United States
• ¹⁷ Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California, United States
• ¹⁸ Oceans Institute, Oceans Graduate School, University of Western Australia, Crawley, Western Australia, Australia
• ¹⁹ Norwegian Meteorological Institute, Oslo, Norway
• ²⁰ Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Kanagawa, Japan
• ²¹ School of Oceanography, College of the Environment, University of Washington, Seattle, Washington, United States
• ²² NTT Space Environment and Energy Laboratories, Musashino, Tokyo, Japan
• ²³ National Marine Mammal Laboratory (MML), Alaska Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Seattle, Washington, United States
• ²⁴ Rosenstiel School of Marine, Atmospheric, and Earth Science, University of Miami, Miami, Florida, United States
• ²⁵ The Cooperative Institute For Marine And Atmospheric Studies,University of Miami, Miami, Florida, United States
• ²⁶ Climate Science Centre, Commonwealth Scientific and Industrial Research Organization, Hobart, Australia
• ²⁷ Cooperative Institute for Climate, Ocean and Ecosystem Studies, College of the Environment, University of Washington, Seattle, Washington, United States
• ²⁸ IMOS Animal Tagging, Sydney Institute of Marine Science, Mosman, NSW, Australia
• ²⁹ Okinawa Institute of Science and Technology Graduate University, Okinawa, Okinawa, Japan
• ³⁰ Southern Ocean Carbon and Climate Observatory (SOCCO), Cape Town, South Africa
• ³¹ Offshore Sensing (Norway), Bergen, Hordaland, Norway
• ³² Akvaplan-niva, Environmental Department, Tromsø, Troms, Norway
• ³³ Ocius Technology, Sydney, Australia
• ³⁴ Centre for Ocean and Atmospheric Sciences, Faculty of Science, University of East Anglia, Norwich, United Kingdom
• ³⁵ Global Ocean Monitoring and Observing Program, National Oceanic and Atmospheric Adminstration, Silver Spring, MD, United States
• ³⁶ Applied Physics Laboratory, University of Washington, Seattle, Washington, United States
• ³⁷ Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, United States

Observing air-sea interactions on a global scale is essential for improving Earth system forecasts. Yet these exchanges are challenging to quantify for a range of reasons, including extreme conditions, vast and remote under-sampled locations, requirements for a multitude of co-located variables, and the high variability of fluxes in space and time. Uncrewed Surface Vehicles (USVs) present a novel solution for measuring these crucial air-sea interactions at a global scale. Powered by renewable energy (e.g., wind and waves for propulsion, solar power for electronics), USVs have provided navigable and persistent observing capabilities over the past decade and a half. In our review of 200 USV datasets and 96 studies, we found USVs have observed a total of 33 variables spanning physical, biogeochemical, biological and ecological processes at the air-sea transition zone. We present a map showing the global proliferation of USV adoption for scientific ocean observing. This review, carried out under the auspices of the 'Observing Air-Sea Interactions Strategy' (OASIS), makes the case for a permanent USV network to complement the mature and emerging networks within the Global Ocean Observing System (GOOS). The Observations Coordination Group (OCG) overseeing GOOS has identified ten attributes of an in-situ global network. Here, we discuss and evaluate the maturation of the USV network towards meeting these attributes. Our article forms the basis of a roadmap to formalise and guide the global USV community towards a novel and integrated ocean observing frontier.