- Title
- Upstream Pc3-4 waves: experimental evidence of propagation to the nightside plasmapause/plasmatrough
- Creator
- Ponomarenko, P. V.; Waters, C. L.; St-Maurice, J. P.
- Relation
- Geophysical Research Letters Vol. 37, Issue 22
- Publisher Link
- http://dx.doi.org/10.1029/2010gl045416
- Publisher
- American Geophysical Union
- Resource Type
- journal article
- Date
- 2010
- Description
- Compressional magnetohydrodynamic (MHD) waves in the Pc3-4 frequency range (≃10–50 mHz) are generally believed to be generated upstream of the Earth's bow-shock in reflected proton beams. Inside the closed field-line geometry, these waves are conventionally considered to be a dayside phenomenon. However, recent studies suggest that some of the nighttime Pc4 pulsations may in fact have an upstream origin. In this letter, we report synchronous variations of the Pc3-4 spectra near post-dawn cusp and nightside plasmapause/plasmatrough as observed by HF radar and ground magnetometers. The measured Pc3-4 frequency closely follows that of the upstream waves theoretically predicted based on the dynamics of the interplanetary magnetic field, which presents the most convincing evidence to date of upstream-generated Pc3-4 waves propagating to the nightside magnetosphere in the closed field-line geometry. We conclude the letter with a brief discussion of a possible propagation scenario.
- Subject
- experimental evidence; magnetohydrodynamic waves; upstream waves; ground magnetometer; HF radars; interplanetary magnetic fields
- Identifier
- http://hdl.handle.net/1959.13/930952
- Identifier
- uon:10962
- Identifier
- ISSN:0094-8276
- Language
- eng
- Full Text
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