Neutral atom imaging of the magnetospheric cusps

• Published in: Journal of Geophysical Research: Space Physics Vol. 116; no. A7
• Main Authors: Petrinec, S. M., Dayeh, M. A., Funsten, H. O., Fuselier, S. A., Heirtzler, D., Janzen, P., Kucharek, H., McComas, D. J., Möbius, E., Moore, T. E., Reisenfeld, D. B., Schwadron, N. A., Trattner, K. J., Wurz, P.
• Format: Journal Article
• Language: English
• Published: Washington Blackwell Publishing Ltd 01.07.2011
• Subjects: Atmospheric sciences; energetic neutral atoms; magnetic reconnection; Magnetism; magnetopause; magnetospheric cusps
• ISSN: 0148-0227; 2169-9380; 2156-2202; 2169-9402
• DOI: 10.1029/2010JA016357

The magnetospheric cusps separate closed dayside magnetospheric field lines from open field lines of the magnetotail mantle and lobes. All magnetospheric field lines that map to the magnetopause also pass through the cusp regions. Thus whenever magnetic reconnection occurs at the magnetopause, magnetosheath plasma can enter one or both of the cusp regions and charge exchange with the geocorona. The resulting energetic neutral atoms (ENAs) resulting from this charge exchange process propagate away from the cusps and are observed remotely by the Interstellar Boundary Explorer (IBEX). The asymmetry of the ENA intensities between the northern and southern cusps are strongly dependent upon the Earth's dipole tilt angle and are consistent with in situ cusp observations. These asymmetric fluxes in the cusp regions are suggested to be explained by the regions at the magnetopause where magnetic reconnection is expected. Key Points First observations of ENAs in the cusps Explains in situ cusp asymmetries Supports magnetopause reconnection models