April 2, 2010, 12:00pm - 1:00 pm

April 2, 2010, 12:00pm - 1:00 pm

Strong Particle Heating at an Atypical Interplanetary Shock

Lynn Wilson (University of Michigan)

We present the first observations of large amplitude (> 100 mV/m peak-to-peak) solitary waves and electron Bernstein waves at an interplanetary shock. The Bernstein waves show enhanced power at integer and half-integer harmonics of the cyclotron frequency with a broadened power spectrum, consistent with the electron cyclotron drift instability. The solitary waves are obliquely polarized with respect to the magnetic field but parallel to the shock normal direction, consistent with the simulation results of Matsukiyo and Scholer, [2006]. Strong particle heating above the adiabatic limit in both the electrons and ions is observed. The observed heating and waveforms are likely due to instabilities driven by the free energy provided by reflected ions at this supercritical interplanetary shock. These results may offer new insights into collisionless shock dissipation and wave-particle interactions in the solar wind.