Plasmapause Surface Wave Oscillates the Magnetosphere and Diffuse Aurora

Abstract:

Energy circulation in geospace lies at the heart of space weather research. In the inner magnetosphere, the steep plasmapause boundary separates the cold dense plasmasphere, which corotates with the planet, from the hot ring current/plasma sheet outside. Theoretical studies suggested that plasmapause surface waves related to the sharp inhomogeneity exist and act as a source of geomagnetic pulsations, and recently we found direct evidence of plasmapause surface waves. Moreover, the waves are found to excite global ULF waves in the magnetosphere, which generate a sawtooth auroral structure at the equatorial auroral boundary. The processes identified along terrestrial plasmapause boundary layer, separating the cororating plasmasphere from the relatively steady magnetosphere, are expected to also exist at other planets, particularly for Saturn and Jupiter which are known to have corotation breakdown magnetospheres.