TY - JOUR T1 - Measuring Global Ocean Heat Content to Estimate the Earth Energy Imbalance A1 - Meyssignac,Benoit A1 - Boyer,Tim A1 - Zhao,Zhongxiang A1 - Hakuba,Maria Z. A1 - Landerer,Felix W. A1 - Stammer,Detlef A1 - Koehl,Armin A1 - Kato,Seiji A1 - L'Ecuyer,Tristan A1 - Ablain,Michael A1 - Abraham,John Patrick A1 - Blazquez,Alejandro A1 - Cazenave,Anny A1 - Church,John A. A1 - Cowley,Rebecca A1 - Cheng,Lijing A1 - Domingues,Catia M. A1 - Giglio,Donata A1 - Gouretski,Viktor A1 - Ishii,Masayoshi A1 - Johnson,Gregory C. A1 - Killick,Rachel E. A1 - Legler,David A1 - Llovel,William A1 - Lyman,John A1 - Palmer,Matthew Dudley A1 - Piotrowicz,Steve A1 - Purkey,Sarah G. A1 - Roemmich,Dean A1 - Roca,Rmy A1 - Savita,Abhishek A1 - von Schuckmann,Karina A1 - Speich,Sabrina A1 - Stephens,Graeme A1 - Wang,Gongjie A1 - Wijffels,Susan Elisabeth A1 - Zilberman,Nathalie AD - Univ Toulouse, IRD, UPS, CNRS,CNES,LEGOS, Toulouse, France. AD - NOAA, Natl Ctr Environm Informat, Silver Spring, MD USA. AD - Univ Washington, Appl Phys Lab, Seattle, WA 98105 USA. AD - CALTECH, Jet Prop Lab, Pasadena, CA USA. AD - Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. AD - Univ Hamburg, Ctr Erdsyst Forsch & Nachhaltigkeit, Hamburg, Germany. AD - NASA, Langley Res Ctr, Hampton, VA 23665 USA. AD - Univ Wisconsin, Dept Atmospher & Ocean Sci, Madison, WI USA. AD - Collecte Localisat Satellite, Ramonville St Agne, France. AD - Univ St Thomas, St Paul, MN USA. AD - Univ New South Wales, Climate Change Res Ctr, Sydney, NSW, Australia. AD - Commonwealth Sci & Ind Res Org, Climate Sci Ctr, Hobart, Tas, Australia. AD - Chinese Acad Sci, Int Ctr Climate & Environm Sci, Inst Atmospher Phys, Beijing, Peoples R China. AD - Univ Tasmania, Inst Marine & Antarctic Studies, Hobart, Tas, Australia. AD - Antarctic Climate & Ecosyst Cooperat Res Ctr, Hobart, Tas, Australia. AD - Australian Res Council, Ctr Excellence Climate Syst Sci, Hobart, Tas, Australia. AD - Univ Colorado, Dept Atmospher & Ocean Sci, Boulder, CO 80309 USA. AD - Univ Hamburg, Ctr Earth Syst Res & Sustainabil, Integrated Climate Data Ctr, CliSAP, Hamburg, Germany. AD - Japan Meteorol Agcy, Meteorol Res Inst, Tsukuba, Ibaraki, Japan. AD - NOAA, Pacific Marine Environm Lab, 7600 Sand Point Way Ne, Seattle, WA 98115 USA. AD - Hadley Ctr, Met Off, Exeter, Devon, England. AD - NOAA, Climate Program Off, Silver Spring, MD USA. AD - Univ Hawaii Manoa, Joint Inst Marine & Atmospher Res, Honolulu, HI 96822 USA. AD - Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92093 USA. AD - Mercator Ocean Int, Ramonville St Agne, France. AD - Ecole Normale Super, Lab Meteorol Dynam, Paris, France. AD - Natl Univ Def Technol, Coll Meteorol & Oceanog, Nanjing, Jiangsu, Peoples R China. AD - Woods Hole Oceanog Inst, Woods Hole, MA 02543 USA. UR - https://archimer.ifremer.fr/doc/00675/78723/ DO - 10.3389/fmars.2019.00432 KW - ocean heat content KW - sea level KW - ocean mass KW - ocean surface fluxes KW - ARGO KW - altimetry KW - GRACE KW - Earth Energy Imbalance N2 - The energy radiated by the Earth toward space does not compensate the incoming radiation from the Sun leading to a small positive energy imbalance at the top of the atmosphere (0.4-1 Wm(-2)). This imbalance is coined Earth's Energy Imbalance (EEI). It is mostly caused by anthropogenic greenhouse gas emissions and is driving the current warming of the planet. Precise monitoring of EEI is critical to assess the current status of climate change and the future evolution of climate. But the monitoring of EEI is challenging as EEI is two orders of magnitude smaller than the radiation fluxes in and out of the Earth system. Over 93% of the excess energy that is gained by the Earth in response to the positive EEI accumulates into the ocean in the form of heat. This accumulation of heat can be tracked with the ocean observing system such that today, the monitoring of Ocean Heat Content (OHC) and its long-term change provide the most efficient approach to estimate EEI. In this community paper we review the current four state-of-the-art methods to estimate global OHC changes and evaluate their relevance to derive EEI estimates on different time scales. These four methods make use of: (1) direct observations of in situ temperature; (2) satellite-based measurements of the ocean surface net heat fluxes; (3) satellite-based estimates of the thermal expansion of the ocean and (4) ocean reanalyses that assimilate observations from both satellite and in situ instruments. For each method we review the potential and the uncertainty of the method to estimate global OHC changes. We also analyze gaps in the current capability of each method and identify ways of progress for the future to fulfill the requirements of EEI monitoring. Achieving the observation of EEI with sufficient accuracy will depend on merging the remote sensing techniques with in situ measurements of key variables as an integral part of the Ocean Observing System. Y1 - 2019/08 PB - Frontiers Media Sa JF - Frontiers In Marine Science SN - 2296-7745 VL - 6 ID - 78723 ER -