1. Here are regions where different kinds of waves are thought to persist
Powerful radio and plasma waves are central to the acceleration and loss of radiation belt particles
Here are regions where different kinds of waves are thought to persist
The Van Allen Probes provide the first simultaneous multipoint measurements of these waves over broad regions

2. Focus on chorus waves that we see on the Van Allen Probes
Powerful radio and plasma waves are central to the acceleration and loss of radiation belt particles
Focus on chorus waves that we see on the Van Allen Probes
Particles can “surf” on waves and gain or loose tremendous amounts of energy
The Van Allen Probes provide the first simultaneous multipoint measurements of these waves over broad regions

3. Resonant Wave Acceleration

4. Some of these waves are striking and beautiful to both the eye ---
Power level triggered waveform capture – 16 bit data – very clear!!
Chorus
Waves

5. --- and to the ear Chorus Waves
Power level triggered waveform capture – 16 bit data – very clear!!
Chorus
Waves

6. Now, unique 2-spacecraft measurements reveal many-hour persistence of Intense Low Frequency Electric Fields
> 5-hours
Van Allen Probe-A
Van Allen Probe-B
October 13, 2012
Universal Time
Waves at the edge of the radiation belts can last at least 5 hours during geomagnetic storms. This may be central to explaining how multi-MeV electrons are energized in the course of less than a day.

7. Van Allen Probes high-cadence sampling reveals strong correlation between chorus waves and magnetic storms
Magnetic Storms
DST Magnetic Storm Parameter
This correlation may be central to the association of strong particle acceleration with some magnetic storms. But, why not all magnetic storms?

8. Summary
The electric field and magnetic field measurements on the Van Allen Probes are the best ever made in the radiation belts.
Two spacecraft is letting us see how long important waves persist – we’ve couldn’t do this before
Magnetospheric activity clearly is correlated with key wave features such as chorus.
These findings may be central to when, where, and how radiation belt particles are accelerated.
This is just the beginning!!