[1] NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA
[2] NASA, Goddard Space Flight Ctr, Ctr Res & Explorat Space Sci & Technol, Greenbelt, MD 20771 USA
[3] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA
[4] Univ Paris 07, Univ Paris Est Creteil, LISA, Creteil, France
[5] Hop Henri Mondor, CNRS, F-94010 Creteil, France
[6] Rensselaer Polytech Inst, Dept Earth & Environm Sci, Troy, NY USA
[7] Rensselaer Polytech Inst, Sch Sci, Troy, NY USA
[8] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA
[9] Univ Nacl Autonoma Mexico, Lab Quim Plasmas & Estudios Planetarios, Inst Ciencias Nucl, Mexico City 04510, DF, Mexico
[10] Cornell Univ, Ithaca, NY USA
[11] Carnegie Inst Sci, Geophys Lab, Washington, DC USA
[12] Georgia Inst Technol, Atlanta, GA 30332 USA