- Title
- Pc2 EMIC waves generated high off the equator in the dayside outer magnetosphere
- Creator
- Liu, Y. H.; Fraser, B. J.; Menk, F. W.
- Relation
- Geophysical Research Letters Vol. 39, Issue 17
- Publisher Link
- http://dx.doi.org/10.1029/2012GL053082
- Publisher
- Wiley-Blackwell Publishing
- Resource Type
- journal article
- Date
- 2012
- Description
- It is generally accepted that electromagnetic ion cyclotron (EMIC) waves are generated around the equatorial regions and propagate toward the high latitude ionospheres in both hemispheres. Here we describe a prolonged EMIC wave event in the Pc2 (0.1–0.2 Hz) frequency band above the He⁺ cyclotron frequency detected by the four Cluster satellites as they traversed sunward from L~ 13 in the outer magnetosphere to the magnetopause, over 13°–20° magnetic latitude north of the equator and across the high latitude cusp region near local magnetic noon. Wave packet energy propagated dominantly along the geomagnetic field direction, confirming this was a traveling EMIC wave rather than a toroidal field line resonance. The energy packets propagated in alternating directions rather than uni-directionally from the equator, implying the wave source was located in a high latitude region away from the equator, where a minimum in the B field is located. The CIS-CODIF H⁺ion data provided evidence that the waves were generated locally via the ion cyclotron instability. We believe the off-equatorial minimum magnetic field regions may be important source regions for these waves in the outer magnetosphere.
- Subject
- Pc2 waves; high latitude; outer magnetosphere
- Identifier
- http://hdl.handle.net/1959.13/1063782
- Identifier
- uon:17371
- Identifier
- ISSN:0094-8276
- Language
- eng
- Full Text
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