Toward an integrated pantropical ocean observing system

Gregory R. Foltz ^1* Yassir A. Eddebbar ² Janet Sprintall ² Antonietta Capotondi ^3,4 Sophie E CRAVATTE ^5,6,7 Peter Brandt ^8,9 Adrienne J Sutton ¹⁰ Tamaryn Morris ¹¹ Juliet Hermes ^11,12 Clive Reginald McMahon ¹³ Michael James McPhaden ¹⁰ Lev B Looney ^1,14,15 Franz Philip Tuchen ^1,16 Roxy Mathew Koll ¹⁷ Fan Wang ¹⁸ Fei Chai ¹⁹ Regina R Rodrigues ²⁰ Belen Rodriguez-Fonseca ^21,22 Aneesh Subramanian ²³ Marcus Dengler ⁸ Cheyenne Stienbarger ²⁴ Kathleen Bailey ²⁵ Weidong Yu ²⁶

• ¹ Atlantic Oceanographic and Meteorological Laboratory (NOAA), Miami, United States
• ² Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California, United States
• ³ NOAA Physical Sciences Laboratory, Boulder, Colorado, United States
• ⁴ Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, Colorado, United States
• ⁵ Université de Toulouse, Toulouse, Midi-Pyrénées, France
• ⁶ UMR5566 Laboratoire d'études en géophysique et océanographie spatiales (LEGOS), Toulouse, Midi-Pyrénées, France
• ⁷ IRD Center, New Caledonia, France
• ⁸ GEOMAR Helmholtz Center for Ocean Research Kiel, Helmholtz Association of German Research Centres (HZ), Kiel, Schleswig-Holstein, Germany
• ⁹ University of Kiel, Kiel, Schleswig-Holstein, Germany
• ¹⁰ Pacific Marine Environmental Laboratory, National Oceanic and Atmospheric Administration (NOAA), Seattle, Washington, United States
• ¹¹ Egagasini Node, South African Environmental Observation Network, Cape Town, South Africa
• ¹² University of Cape Town, Cape Town, South Africa
• ¹³ Sydney Institute of Marine Science, Faculty of Science, University of New South Wales, Sydney, New South Wales, Australia
• ¹⁴ University of Miami, Coral Gables, Florida, United States
• ¹⁵ The Cooperative Institute For Marine And Atmospheric Studies,University of Miami, Miami, Florida, United States
• ¹⁶ Cooperative Institute for Marine and Atmospheric Studies, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, Florida, United States
• ¹⁷ Indian Institute of Tropical Meteorology (IITM), Pune, Maharashtra, India
• ¹⁸ Chinese Academy of Sciences, Qingdao, China
• ¹⁹ State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian Province, China
• ²⁰ Federal University of Santa Catarina, Florianopolis, Santa Catarina, Brazil
• ²¹ Complutense University of Madrid, Madrid, Madrid, Spain
• ²² Geosciences Institute UCM-IGEO, Madrid, Spain
• ²³ University of Colorado Boulder, Boulder, Colorado, United States
• ²⁴ NOAA Global Ocean Monitoring and Observing, Silver Spring, United States
• ²⁵ NOAA Integrated Ocean Observing System, Silver Spring, United States
• ²⁶ Sun Yat-sen University, Guangdong, China

Global climate is regulated by the ocean, which stores, releases, and transports large amounts of mass, heat, carbon, and oxygen. Understanding, monitoring, and predicting the exchanges of these quantities across the ocean's surface, their interactions with the atmosphere, and their horizontal and vertical pathways through the global oceans, are key for advancing fundamental knowledge and improving forecasts and longer-term projections of climate, weather, and ocean ecosystems. The existing global observing system provides immense value for science and society in this regard by supplying the data essential for these advancements. The tropical ocean observing system in particular has been developed over decades, motivated in large part by the far-reaching and complex global impacts of tropical climate variability and change. However, changes in observing needs and priorities, new challenges associated with climate change, and advances in observing technologies demand periodic evaluations to ensure that stakeholders' needs are met. Previous reviews and assessments of the tropical observing system have focused separately on individual basins and their associated observing needs. Here we provide a broader perspective covering the tropical observing system as a whole. Common gaps, needs, and recommendations are identified, and interbasin differences driven by socioeconomic disparities are discussed, building on the concept of an integrated pantropical observing system. Finally, recommendations for improved observations of tropical basin interactions, through oceanic and atmospheric pathways, are presented, emphasizing the benefits that can be achieved through closer interbasin coordination and international partnerships.