Electric (EDI) and magnetic (FGM) fields of a complicated, mixed-mode wave
observed on open field lines in the polar cap. The magnetic perturbation in
the upper left panel is a superposition of two frequencies, as shown in the
center, top panel. The lower frequency oscillation is essentially the same at
all three s/c, while the higher frequency part, identified as an Alfven wave,
has markedly different phases and amplitudes at the s/c positions. The
magnetic and velocity components are approximately in quadrature (lower right)
indicating a standing wave.
Last modified: Thu Mar 25 13:24:32 EST 2004