First ENA observations at Mars:: Subsolar ENA jet

被引：36

作者：

Futaana, Y.

Barabash, S.

Grigoriev, A.

Holmstrom, M.

Kallio, E.

C son Brandt, P.

Gunell, H.

Brinkfeldt, K.

Lundin, R.

Andersson, H.

Yamauchi, M.

McKenna-Lawler, S.

Winningham, J. D.

Frahm, R. A.

Sharber, J. R.

Scherrer, J. R.

Coates, A. J.

Linder, D. R.

Kataria, D. O.

Sales, T.

Riihela, P.

Schmidt, W.

Koskinen, H.

Kozyra, J.

Luhmann, J.

Roelof, E.

Williams, D.

Livi, S.

Curtis, C. C.

Hsieh, K. C.

Sandel, B. R.

Grande, M.

Carter, M.

Sauvaud, J. -A.

Fedorov, A.

Thocaven, J. -J.

Orsini, S.

Cerulli-Irelli, R.

Maggi, M.

Wurz, P.

Bochsler, P.

Krupp, N.

Woch, J.

Fraenz, M.

Asamura, K.

Dierker, C.

机构：

[1] Swedish Inst Space Phys, SE-98128 Kiruna, Sweden

[2] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA

[3] Finnish Meteorol Inst, FIN-00101 Helsinki, Finland

[4] Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA

[5] Natl Univ Ireland, Space Technol Ireland, Maynooth, Kildare, Ireland

[6] SW Res Inst, San Antonio, TX 78228 USA

[7] UCL, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England

[8] Univ Helsinki, Dept Phys Sci, FIN-00014 Helsinki, Finland

[9] Univ Michigan, Space Phys Res Lab, Ann Arbor, MI 48109 USA

[10] Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA

[11] Univ Arizona, Tucson, AZ 85721 USA

[12] Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England

[13] Ctr Etud Spatiale Rayonnements, F-31028 Toulouse, France

[14] Ist Fis Spazio Interplanetario, I-00133 Rome, Italy

[15] Univ Bern, Inst Phys, CH-3012 Bern, Switzerland

[16] Max Planck Inst Aeron, D-37191 Katlenburg Lindau, Germany

[17] Inst Space & Astronaut Sci, Sagamihara, Kanagawa, Japan

[18] Tech Univ Braunschweig, D-38106 Braunschweig, Germany

来源：

ICARUS | 2006年 / 182卷 / 02期

关键词：

Mars; atmosphere; solar wind; magnetospheres;

D O I：

10.1016/j.icarus.2005.08.024

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

The Neutral Particle Detector (NPD), an Energetic Neutral Atom (ENA) sensor of the Analyzer of Space Plasmas and Energetic Atoms (ASPERA-3) on board Mars Express, detected intense fluxes of ENAs emitted from the subsolar region of Mars. The typical ENA fluxes are (4-7) x 10(5) cm(-2) sr(-1) s(-1) in the energy range 0.3-3 keV. These ENAs are likely to be generated in the subsolar region of the martian exosphere. As the satellite moved away from Mars, the ENA flux decreased while the field of view of the NPD pointed toward the subsolar region. These decreases occurred very quickly with a time scale of a few tens of seconds in two thirds of the orbits. Such a behavior can be explained by the spacecraft crossing a spatially constrained ENA jet, i.e., a highly directional ENA emission from a compact region of the subsolar exosphere. This ENA jet is highly possible to be emitted conically from the subsolar region. Such directional ENAs can result from the anisotropic solar wind flow around the subsolar region. but this can not be explained in the frame of MHD models. (c) 2005 Elsevier Inc. All rights reserved.

引用

页码：413 / 423

页数：11

共 25 条

[1] Magnetic field and plasma observations at Mars:: Initial results of the Mars global surveyor mission [J].