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Science teams for the joint U.S.-French Topex/Poseidon oceanographic satellite mission have been selected by NASA and the Centre National d'Etudes Spatiales


Topex/Poseidon, scheduled for launch on the European Space Agency's Ariane rocket in December 1991, will carry instruments in near-polar orbit around the Earth to measure the ocean's circulation in detail. The U.S. portion of the mission is managed by the Jet Propulsion Laboratory, Pasadena, Calif.

Data from the satellite and from other international experiments planned at the same time will produce the most extensive studies of the world's oceans ever undertaken.

The primary instrument aboard Topex/Poseidon will be radar altimeter, which bounces signals off the ocean's surface as the satellite passes over the Earth. The time required for the signal to return to the radar gives precise measurement of the distance between the satellite and the sea surface.

Using other instruments to pinpoint the satellites's position in space, experimenters will be able to produce detailed map of the topography of the ocean surface. The height variations on the surface of the ocean are directly related to currents, eddies, and other features of ocean circulation. By taking into account the influence of the Earth's gravity field on ocean surface topography, researchers will also be able to calculate major features of the sea floor.

NASA will provide the satellite, altimeter, another instrument, and various spacecraft subsystems. The French will supply the Ariane, and will place two instruments, including second altimeter, on the satellite.

Charles Yamarone of JPL is Topex project manager. Dr. Robert Stewart of JPL and the Scripps Institution of Oceanography, La Jolla, Calif., is Topex project scientist. James Richman of NASA Headquarters is program scientist and William Townsend, also of NASA Headquarters, is program manager.

NASA chose the following scientists and their investigations for the U.S portion of the Topex/Poseidon mission:

- Dr. George Born, University of Colorado, Boulder, Colo.; "The Use of Satellite Altimetry in the Study of Weakly Defined and Variable Oceanic Gyres."

- Dr. Derek Burrage, Australian Institute of Marine Science, Townsville, Queensland, Australia; "North-Australian Tropical Seas Circulation Study."

- Dr. Dudley Chelton, Oregon State University, Corvallis, Ore.; "Mesoscale and Large-Scale Variability in the Antarctic Circumpolar Current."

- Dr. John Church, Commonwealth Scientific and Industrial Research Organization, Division of Oceanography, Hobart, Tasmania, Australia; "Dynamics and Topography of the South Pacific, Southern and Indian Oceans."

- Dr. Bruce Douglas, National Oceanic and Atmospheric Administration/National Geodetic Survey, Rockville, Md.; "Analysis of Topex/Poseidon Altimeter Data for Global Studies of Sea Level Variability, Absolute Dynamic Topography, Geophysics, and Tidal Model Improvement."

- Dr. Lee-Leung Fu, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, Calif.; "Circulation of the Gyres of the World Ocean: Observation and Modeling Using Topex/Poseidon Altimeter Data."

- Dr. Eli Katz, Lamont-Doherty Geological Observatory, Columbia University, Palisades, N.Y.; "Sea Level Response to Wind-Forcing in the Tropical Atlantic."

- Dr. Timothy Liu, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, Calif.; "Low-Frequency Variability of Sea Level as Related to the Heat Balance of Global Oceans."

- Dr. Roger Lukas, University of Hawaii, Honolulu, Hawaii; "Studies of Tropical Ocean Dynamics Using the Topex/Poseidon Altimeter-Derived Sea Surface Topography."

- Dr. James Marsh, NASA/Goddard Space Flight Center, Greenbelt, Md.; "Ocean Topography Mapping, Improvement of the Marine Geoid, and Global Permanent Ocean Circulation Studies from Topex Altimeter Data."

- Dr. James L. Mitchell, Naval Research and Development Activity, National Space Technology Laboratories, Miss.; "The Dynamics and Energetics of Mid-Latitude Western Boundary Currents: Comparison of the Kuroshio Extension and the Gulf Stream."

- Dr. Richard Rapp, Ohio State University, Columbus, Ohio; "Altimeter Research in Ocean Circulation."

- Dr. Braulio Sanchez, NASA/Goddard Space Flight Center, Greenbelt, Md.; "Global Ocean Tide Mapping Using Topex Altimetry."

- Dr. Jiro Segawa, Ocean Research Institute, Tokyo, Japan; "Application of Precise Altimetry to the Study of the Precise Leveling, the Earth's Gravity Field, and the Rotation of the Earth."

- Dr. Ted Strub, Oregon State University, Corvallis, Oregon; "Equatorial and Eastern Boundary Current Variability in the North and South Pacific Ocean.'

- Dr. Chang-Kou Tai, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, Calif.; "An Integrated Research Program for Topex/Poseidon with Emphasis on the Pacific Ocean."

- Dr. Keisuke Taira, Ocean Research Institute, Tokyo, Japan; "Oceanic Transports of Mass, Heat and Salt in the Western North Pacific."

- Dr. Byron Tapley, University of Texas, Austin, Tex.; "The Determination and Interpretation of Ocean Surface Topography Using Topex/Poseidon Altimeter Data."

- Dr. John Wahr, University of Colorado, Boulder, Colo.; "A Topex/Poseidon Study of Oceanic Effects on Observations of the Earth's Interior."

- Dr. Carl Wunsch, Massachusetts Institute of Technology, Cambridge, Mass.; "Altimetry Research in Ocean Circulation."

France's Centre National d'Etudes Spatiales (CNES) chose the following investigators and experiments for its portion of the mission:

- Dr. Tom Allan, Institute of Oceanographic Sciences, Wormley, Surrey, England; "Marine Research Using Data from Topex/Poseidon."

- Dr. F. Barlier, Groupe de Recherches de Geodesie Spatiale, Toulouse, France; "Altimetric Studies of the Mediterranean."

- Dr. Claude Boucher, Institut Geographique National, Saint-Mande, France; "Terrestrial Reference Systems Related to Topex/Poseidon."

- Dr. Anny Cazenava, Groupe de Recherches de Geodesie Spatiale, Toulouse, France; "Geophysics Investigations with Topex/Poseidon Altimeter Data."

- Dr. Pierre De Mey, Groupe de Recherches de Geodesie Spatiale, Toulouse, France; "Satellite Assimilation of Topographic Heights into Models of Ocean."

- Dr. Yves Desaubies, Institut Francais de Recherche pour l'Exploration de la Mer, Centre de Brest, Brest, France; "Studies of Intermediate and Large Circulation in the Equatorial Western Atlantic."

- Dr. Marten Grundlingh, National Research Institute for Oceanology, Stellenbosch, South Africa; "South African Topex/Poseidon Altimeter Experiment."

- Dr. Christian Le Provost, Institut de Mechanique de Grenoble, Grenoble, France; "Assimilation of Oceanographic and Altimetric Satellite Data in Hydrodynamic Model."

- Dr. Yves Menard, Groupe de Recherches de Geodesie Spatial, Toulouse, France; "Geophysical Validation of Altimetric Data from Topex/Poseidon."

- Dr. Jacques Merle, Universite Paris VI, Paris, France; "Study of Mass and Heat Transport of the Tropical Atlantic Ocean Using Model Simulations and Topex/Poseidon Altimeter Data."

- Jean-Francois Minster, Groupe de Recherches de Geodesie Spatiale, Toulouse, France; "Observations of Mesoscale Variability and Basin Scale of the Dynamic Topography of the Oceans."

- Dr. Dirk Olbers, Alfred Wegener Institut fur Polar und Meeresforschung Bremerhaven, Federal Republic of Germany; "Ocean Circulation Modeling by use of Radar Altimeter Data."

- Dr. Michel Ollitrault, Institut Francais de Recherche pour l'Exploration de la Mer, Centre de Brest, Brest, France; "Circulation of the South Atlantic."

- Dr. Lasse Pettersson, University of Bergen, Bergen, Norway; "Ocean Dynamics in the Nordic Seas Using Satellite Altimetry."

- Dr. Joel Picaut, Centre de Noumea, Noumea, New Caledonia; "Application of Topex/Poseidon Altimetry to Observational and Modeling Studies of the Low-Frequency Upper Ocean Mass and Heat Circulation in the Tropical Pacific."

- Dr. Annie Souriau, Groupe de Recherches de Geodesie Spatiale, Toulouse, France; "Actual Movements of the Lithospheric Plates, Determined in Part by Topex/Poseidon Data."

- Dr. Pascal Tarits, Institut de Physique du Globe de Paris, Paris, France; "Studies of the Global Ocean Circulation Using Measurments of the Deep Electromagnetic Field and Satellite Altimeter Data."

- Prof. K.F. Wakker, Delft University of Technology, Delft, The Netherlands; "Precise Orbit Computation and Sea Surface Modeling in the North Atlantic, the West Pacific, and the Antarctic."

The Topex/Poseidon mission's timing is planned to coincide with other key oceanographic experiments in the early 1990s, including the World Ocean Circulation Experiment (WOCE) and the Tropical Oceans Global Atmospheres Experiment (TOGA). These decade-long programs, sponsored by the World Climate Research Program, involve studies at and below the ocean surface in all parts of the world's seas.

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