jgra21780.pdf (2.4 MB)
Download file

Upstream-generated Pc3 ULF wave signatures observed near the Earth's cusp

Download (2.4 MB)
journal contribution
posted on 24.10.2012, 08:56 by T. K. Yeoman, D. M. Wright, M. J. Engebretson, V. A. Pilipenko, M. R. Lessard, H. Kim
[1] Pc3 pulsations (frequency ∼20–100 mHz) which originate in the ion foreshock upstream of the Earth's bow shock due to the interaction between reflected ions and the solar wind are frequently observed in ground-based pulsation magnetometer data. Previous studies have noted increased Pc3 wave power in the vicinity of the dayside cusp and inferred that the upstream waves gained entry via the cusp, although more recent studies have revealed a more complex picture. Here, we examine Pc3 wave power near local noon observed by search coil magnetometers at three closely-spaced stations on Svalbard, during times when an extended interval of HF radar backscatter indicative of the cusp is detected by the Hankasalmi SuperDARN radar. The location of the equatorward edge of the HF radar cusp may then be directly compared with the Pc3 wave power measured at three latitudes as the cusp migrates across the stations on a statistical basis. These observations are more consistent with wave entry to the magnetosphere along closed field lines equatorward of the cusp via the ionospheric transistor mechanism of Engebretson et al. (1991a), or weakly coupled fast and Alfvén wave modes, which then map to the low-latitude boundary layer or outer magnetosphere, rather than with wave entry into the magnetosphere via the cusp proper or exterior cusp.

History

Citation

Journal of Geophysical Research A: SPACE PHYSICS, 2012, 117 (3)

Version

VoR (Version of Record)

Published in

Journal of Geophysical Research A: SPACE PHYSICS

Publisher

American Geophysical Union (AGU); Wiley

issn

0148-0227

Copyright date

2012

Available date

24/10/2012

Publisher version

http://onlinelibrary.wiley.com/doi/10.1029/2011JA017327/abstract

Language

en

Usage metrics

Categories

Keywords

Exports