Publication Date:
2016-08-18
Description:
Magnetic compressional structures ahead of a dipolarization front (DF) on 30 August 2002 are investigated by using Cluster data. Our findings are as follows: (1) the structures, observed near the neutral sheet, are mainly compressional and dominant in B Z ; (2) they are almost non-propagating relative to the local ion bulk flow and their lengths are several local proton gyroradius; (3) the ion density increases when B T decreases; (4) ions are partially trapped by the structures with parallel and perpendicular velocities varying in anti-phase; (5) local conditions are favorable for excitation of the mirror instability and we suggest that these structures are mirror mode-like. Our findings also suggest that local conditions ahead of the DF are viable for exciting the mirror instability to generate mirror mode waves or structures.
Print ISSN:
0094-8276
Electronic ISSN:
1944-8007
Topics:
Geosciences
,
Physics