Quasi-periodic Whistler Mode Waves Detected by the Van Allen Probes Spacecraft

Thursday, 18 December 2014
George B Hospodarsky1, Ondrej Santolik2, Frantisek Nemec3, William S Kurth1, Craig Kletzing1, Scott R Bounds1, John R Wygant4 and John W Bonnell5, (1)University of Iowa, Iowa City, IA, United States, (2)Academy of Sciences of the Czech Republic, Prague, Czech Republic, (3)Charles University, Prague, 180, Czech Republic, (4)University of Minnesota Twin Cities, Minneapolis, MN, United States, (5)University of California Berkeley, Berkeley, CA, United States
Quasi-periodic (QP) whistler mode electromagnetic emissions have been detected in Earth’s magnetosphere by the Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS) Waves instrument. These emissions typically consist of intervals of enhanced wave power between a few hundred Hz to a few kHz with modulation periods on the order of minutes. These emissions are primarily observed on the dayside and detected between L shells of 3 to 6, though some events are observed down to L shells of ~2. EMFISIS simultaneously measures the vector wave magnetic field and, with the support of the Electric Fields and Waves (EFW) instrument sensors, the vector wave electric field at two locations in Earth's magnetosphere in a continuous survey mode (typically with a 6 second cadence) along with a number of different burst modes to provide high time resolution waveforms (35000 samples per second). These two modes allow a systematic survey of the occurrence of these waves. By measuring all six wave components simultaneously, the wave propagation parameters, such as the wave normal angle and Poynting vector, of these plasma wave emissions are obtained. We will present a statistical survey of the properties of these waves as detected by the Van Allen Probes, examine their occurrence location and use burst data to examine the fine structure of individual events.