We present results from a statistical analysis of the oscillatory motion of the magnetopause based on THEMIS spacecraft observations, yielding the first experimental evidence for the existence of standing Alfvénic surface or Kruskal‐Schwarzschild modes at the magnetopause. The magnetopause boundary represents a membrane under tension, which may resonantly interact with magnetospheric cavity or waveguide modes. Ultra‐low “magic” geomagnetic pulsation frequencies, often observed in ground‐based and ionospheric measurements and attributed to these cavity or waveguide modes, agree with the detected magnetopause oscillation frequencies and are reinterpreted in terms of surface mode eigenfrequencies.
No takes yet. Share an insight, caveat, or question.
Plaschke et al. (2009) studied this question.