Mode Conversion and Anomalous Transport in Kelvin-Helmholtz Vortices and Kinetic Alfvén Waves at the Earth's Magnetopause

Acuna, M.; Fujimoto, M.; Reme, H.; Goldstein, M. L.; Fazakerley, A.; Mozer, F. S.; Wilber, M.; Chaston, C. C.

United States, Japan, France, United Kingdom

Abstract

Observations at the Earth’s magnetopause identify mode conversion from surface to kinetic Alfvén waves at the Alfvén resonance. Kinetic Alfvén waves radiate into the magnetosphere from the resonance with parallel scales up to the order of the geomagnetic field-line length and spectral energy densities obeying a k-2.4 power law. Amplitudes at the Alfvén resonance are sufficient to both demagnetize ions across the magnetopause and provide field-aligned electron bursts. These waves provide diffusive transport across the magnetopause sufficient for boundary layer formation.

2007 Physical Review Letters
Cluster 74