Cluster observations of fast magnetosonic waves in the heliosphere current sheet
Tuesday, 2 September 2014
Regency Ballroom (Hyatt Regency)
Lei Dai1, John R Wygant1, Cynthia A Cattell1, Scott A Thaller1, Kris Kersten2, Aaron Breneman1 and Xiangwei Tang1, (1)University of Minnesota Twin Cities, Minneapolis, MN, United States, (2)University of Minnesota, Minneapolis, MN, United States
Abstract:
We present Cluster spacecraft observations of large-amplitude fast-mode magnetosonic waves in the heliospheric current sheet (HCS). Multiple current layers are detected using four-point curlometer analysis within the HCS. Current layers are found in correspondence with small-scale magnetic discontinuities. Fast magnetosonic waves are observed at one current layer, accompanying the phase-steeped edge of a large-amplitude transverse Alfven wave. The observed fast-mode waves are in the frequency range 0.01 Hz-0.2 Hz, characterized by a strong correlation between fluctuations of plasma density and magnetic field strength. The observation of fast-mode wave associated with the phase-steepened edge of Alfven wave is consistent with predications of previous numerical simulations, suggesting that the generation of the fast-mode waves may relate to the evolution of large amplitude Alfven wave (rotational discontinuity) in solar wind.
