Providing ocean surface current data in support of Ocean Challenges, Climate Action and Life Below Water: applications of the SKIM proposal for a first space-borne Doppler Wave and Current Scatterometer
Fabrice Ardhuin1,2, Craig Donlon3, Jamie Shutler4, Peter Brandt5, Erik van Sebille6, Marie-Helene Rio7, Alessandro Battaglia8, Fabrice Collard9, Geir Engen10, Paco Lopez Dekker11, Adrien CH Martin12, Detlef Stammer13, Michel Tsamados14, Ernesto Rodriguez15, Bjorn Rommen16, Tania G D Casal17, Gerhard Ressler18, Gérald Dibarboure19, Francois Boy20, Pierre Dubois21, François Soulat21, Clement Ubelmann22, Bertrand Chapron23, Lucile Gaultier24, Frederic Nouguier25, Jean-Marc Delouis26, Goulven Monnier27, Stéphane Méric28, Charles Peureux26,29, Mickael Accensi26, Victor Onink30, Philippe Delandmeter31, Erik de Witte18, Martin Suess32, Paolo Bensi33, Christophe Maes34 and Sophie E Cravatte35, (1)CNRS, Laboratoire d'Oceanographie Physique et Spatiale (LOPS), UMR6523 CNRS/IFREMER/IRD/UBO, Paris Cedex 16, France, (2)University of California, San Diego, Scripps Institution of Oceanography, La Jolla, United States, (3)European Space Agency, ESTEC/EOP-SME, Noordwijk, Netherlands, (4)University of Exeter, Centre for Geography, Environment and Society, Penryn, United Kingdom, (5)GEOMAR, Kiel, Germany, (6)Utrecht University, Institute for Marine and Atmospheric research Utrecht, Utrecht, Netherlands, (7)European Space Research Institute, Frascati, Italy, (8)Earth Observation Science Group, Department of Physics and Astronomy, and National Centre for Earth Observation, University of Leicester, Leicester, United Kingdom, Leicester, United Kingdom, (9)Organization Not Listed, Washington, DC, United States, (10)Northern Research Institute, Tromsø, Norway, (11)Delft University of Technology, Delft, Netherlands, (12)National Oceanography Centre, Southampton, United Kingdom, (13)Universität Hamburg, Centrum für Erdsystemforschung und Nachhaltigkeit, Institute of Oceanography, Hamburg, Germany, (14)UCL CPOM, London, United Kingdom, (15)Jet Propulsion Laboratory, Pasadena, CA, United States, (16)European Space Agency, Noordwijk, Netherlands, (17)ESA, ESTEC, Noordwijk, Netherlands, (18)European Space Agency, Nordwijk, Netherlands, (19)CNES French National Center for Space Studies, Toulouse, France, (20)CNES French National Center for Space Studies, Toulouse Cedex 09, France, (21)CLS Collecte Localisation Satellites, Ramonville St Agne, France, (22)Jet Propulsion Laboratory, Pasadena, United States, (23)IFREMER, Univ. Brest, CNRS, IRD, Laboratoire d'Océanographie Physique et Spatiale, Brest, France, (24)OceanDataLab, Brest, France, (25)IFREMER, Laboratoire d'Oceanographie Physique et Spatiale (LOPS), UMR6523 CNRS/IFREMER/IRD/UBO, Brest, France, (26)LOPS, Brest, France, (27)Scalian, Rennes, France, (28)Université de Rennes 1, Institut d'Electronique et des Télécommunications de Rennes, CNRS UMR 6164, Rennes, France, (29)IFREMER, Plouzané, France, (30)University of Bern, Climate and Environmental Sciences, Bern, Switzerland, (31)Utrecht University, Utrecht, Netherlands, (32)European Space Research and Technology Centre, Noordwijk Zh, Netherlands, (33)European Space Research and Technology Centre, Noordwijk, Netherlands, (34)UBO, CNRS, IRD, Ifremer, Laboratoire d'Océanographie Physique et Spatiale, Plouzané, France, Plouzane, France, (35)LEGOS, Université de Toulouse, (IRD, CNES, CNRS, UPS), Toulouse, France
Abstract:
The Total Surface Current Velocity (TSCV) is an Essential Climate Variable (ECV) that is today only estimated indirectly and at very coarse resolution: the TSCV is the actual vector velocity of water at the sea surface that carries heat, freshwater, carbon, plankton, plastics and everything that is in the water. The transport properties of the TSCV are markedly different from the "geostrophic velocity" inferred from satellite altimetry, and typically also contains the Ekman currents and Stokes drift, as illustrated by the simulated transport of ocean surface particles in the figure below. Better knowledge of this transport and air-sea exchanges can contribute to the United Nations Sustainable Development Goals (SDGs, United Nations 2015).
Measuring directly the TSCV is a long-standing challenge for Earth Observation and Earth system science. SKIM has been developed in the context of the European Space Agency and could be the first satellite to measure directly the ocean surface current vector using an innovative Doppler Wave and Current Scatterometer concept that builds on the heritage of satellite altimetry with the addition of side-looking beams and Doppler processing for velocity measurements (ESA 2019).
SKIM is directly relevant to five of the SDGs, as illustrated below. Indeed, climate mitigation and adaptation measures (SDG13) can benefit from more accurate forecasting of ocean surface temperature, particularly in the tropics, derived from the analysis of heat and freshwater transport, with direct impact on weather and extreme events. Understanding and managing marine life and biodiversity (SDG14) in an stressed ocean requires knowledge of the currents that transport ecosystems and stressors (heat, low oxygen, pollutions). That same knowledge is needed for spatial marine planning and sustainable marine food production (SDG12 and SDG2), or the design and management of ocean energy systems for affordable and clean energy provision (SDG7).
Finally, The combination of SKIM currents with other data sources, including co-located measurements of wind, ocean color and temperature from other sensors can provide much insight into key climate processes that are poorly represented in models today. SKIM data would be a key ingredient for any future ocean-based solutions to Society Greatest Global Challenges.
