Magnetospheric whistler waves were first observed by Storey (1953), who interpreted them as evidence of plasma around Earth. The found region was, of course, plasmasphere, and ground-based whistler observations of have subsequently been used to monitore the plasmapause location. Whistlers have also provided an indirect way to estimate plasmaspheric electric fields (Carpenter et al., 1972). This is because the whistler ducts move radially under the influence of the azimuthal electric field.
Whistler mode waves can create auroral region lower hybrid waves (see ion outflow event). They can also produce isolated bursts of precipitating electrons in mid-latitudes (Rosenberg et al., 1971). In the magnetosheath, "lion roars" occur in intense and sporadic bursts around 100 Hz, corresponding to 0.25 - 0.5 times the electron cyclotron frequency, with average duration of 1-2 s (Smith et al., 1969; Smith and Tsurutani, 1976; Zhang et al., 1998).
In addition, it has been shown that they can be generated by electrical transmission lines: these are the so-called power line harmonics.
- Carpenter, D. L., K. Stone, J. C. Siren, and T. L. Crystal, Magnetospheric electric fields deduced from drifting whistler paths, J. Geophys. Res., 77, 2819, 1972.
- Rosenberg, T. J., R. A. Helliwell, and J. P. Katsufrakis, Electron precipitation associated with discrete very low frequency emissions, J. Geophys. Res., 76, 8445, 1971.
- Smith, E. J., R. E. Holtzer, and C. T. Russell, Magnetic emissions in the magnetosheath at frequencies near 100 Hz,J. Geophys. Res., 74, 3027-, 1969.
- Smith, E. J., and B. T. Tsurutani, Magnetosheath lion roars,J. Geophys. Res., 81, 2261-, 1976.
- Storey, L. R. O., An investigation of whistling atmospherics, Phil. Trans. Roy. Soc., 246, 113, 1953.
- Zhang, Y., H. Matsumoto, and H. Kojima, Lion roars in the magnetosheath: The Geotail observations, J. Geophys. Res., 103, 4615-4626, 1998.