K. Nykyri1, A. Otto2, B. Lavraud3, C. Mouikis4, L. M. Kistler4, A. Balogh1, H. Rème5
1The Blackett Laboratory, Imperial College, London, UK
2Geophysical Institute, University of Alaska, Fairbanks, USA
3Los Alamos National Laboratory, New Mexico, USA
4University of New Hampshire USA
5Centre d’Etude Spatiale Rayonnements, Toulouse, France
Tóm tắt
Abstract. On 3 July 2001, the four Cluster satellites traversed along the dawnside magnetospheric flank and observed large variations in all plasma parameters. The estimated magnetopause boundary normals were oscillating in the z-direction and the normal component of the magnetic field showed systematic 2–3 min bipolar variations for 1 h when the IMF had a small positive bz-component and a Parker-spiral orientation in the x,y-plane. Brief 33 s intervals with excellent deHoffman Teller frames were observed satisfying the Walén relation. Detailed comparisons with 2-D MHD simulations indicate that Cluster encountered rotational discontinuities generated by Kelvin-Helmholtz instability. We estimate a wave length of 6 RE and a wave vector with a significant z-component.
