Multiple cusps during an extended northward IMF period with a significant By component - Zong, Q-G; Zhang, H; Fritz, TA; Goldstein, ML; Wing, S; Keith, W; Winningham, JD; Frahm, R; Dunlop, MW; Korth, A; Daly, PW; Reme, H; et al. (JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, 2008)