Energetic neutral atoms from the Earth's subsolar magnetopause

• Published in: Geophysical research letters Vol. 37; no. 13
• Main Authors: Fuselier, S. A., Funsten, H. O., Heirtzler, D., Janzen, P., Kucharek, H., McComas, D. J., Möbius, E., Moore, T. E., Petrinec, S. M., Reisenfeld, D. B., Schwadron, N. A., Trattner, K. J., Wurz, P.
• Format: Journal Article
• Language: English
• Published: Washington, DC Blackwell Publishing Ltd 01.07.2010; American Geophysical Union; John Wiley & Sons, Inc
• Subjects: Astrophysics; Atmospheric sciences; charge exchange; Earth sciences; Earth, ocean, space; Energetic neutral atoms; Exact sciences and technology; Magnetism; magnetosheath; Planetology; Plasma physics; solar wind; Space; CLUSTER satellite; models; Hydrogen neutral atoms; Energetic neutral atom; Charge exchange; density; Magnetosheath; Magnetopause; hydrogen; solar wind; Earth; extreme value; protons; direction; Simultaneous observation
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/2010GL044140

The shocked solar wind in the Earth's magnetosheath becomes nearly stationary at the subsolar magnetopause. At this location, solar wind protons are neutralized by charge exchange with neutral hydrogen atoms at the extreme limits of the Earth's tenuous exosphere. The resulting Energetic Neutral Atoms (ENAs) propagate away from the subsolar region in nearly all directions. Simultaneous observations of hydrogen ENAs from the Interstellar Boundary Explorer (IBEX) and proton distributions in the magnetosheath from the Cluster spacecraft are used to quantify this charge exchange process. By combining these observations with a relatively simple model, estimates are obtained for the ratio of ENA to shocked solar wind flux (about 10−4) and the exospheric density at distances greater than 10 Earth Radii (RE) upstream from the Earth (about 8 cm−3).