Location
Yosemite National Park
Start Date
2-11-2014 11:00 AM
End Date
2-11-2014 11:30 AM
Description
The twin Van Allen Probes spacecraft were launched on August 30, 2012 to study the Earth's Van Allen radiation belts. The Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS) investigation includes a plasma wave instrument (Waves) that simultaneously measures three orthogonal components of the wave magnetic field from ~10 Hz to 12 kHz and, with the support of the Electric Fields and Waves (EFW) instrument sensors, three components of the wave electric field from ~10 Hz to 12 kHz and a single electric component up to ~400 kHz. Since launch, a variety of plasma waves have been detected which are believed to play a role in the dynamics of the radiation belts, including whistler-mode chorus, plasmaspheric hiss, and magnetosonic equatorial noise. Lightning produced whistlers, electron cyclotron harmonic (ECH) emission, and the upper hybrid resonance (UHR) are also often detected. The UHR is used to determine the local electron plasma density (an important parameter of the plasma required for various modeling and simulation studies). Measuring all six components simultaneously allow the wave propagation parameters of these plasma wave emissions, including the Poynting flux, wave normal vector, and polarization, to be obtained. The Waves instrument is able to determine these parameters with both onboard and ground processing at very high time and frequency resolutions. We will summarize the EMFISIS plasma wave observations and discuss their role in the Van Allen Radiation Belt dynamics.
Plasma Wave Measurements from the Van Allen Probes
Yosemite National Park
The twin Van Allen Probes spacecraft were launched on August 30, 2012 to study the Earth's Van Allen radiation belts. The Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS) investigation includes a plasma wave instrument (Waves) that simultaneously measures three orthogonal components of the wave magnetic field from ~10 Hz to 12 kHz and, with the support of the Electric Fields and Waves (EFW) instrument sensors, three components of the wave electric field from ~10 Hz to 12 kHz and a single electric component up to ~400 kHz. Since launch, a variety of plasma waves have been detected which are believed to play a role in the dynamics of the radiation belts, including whistler-mode chorus, plasmaspheric hiss, and magnetosonic equatorial noise. Lightning produced whistlers, electron cyclotron harmonic (ECH) emission, and the upper hybrid resonance (UHR) are also often detected. The UHR is used to determine the local electron plasma density (an important parameter of the plasma required for various modeling and simulation studies). Measuring all six components simultaneously allow the wave propagation parameters of these plasma wave emissions, including the Poynting flux, wave normal vector, and polarization, to be obtained. The Waves instrument is able to determine these parameters with both onboard and ground processing at very high time and frequency resolutions. We will summarize the EMFISIS plasma wave observations and discuss their role in the Van Allen Radiation Belt dynamics.