Recent advances in plasmaspheric wave research

If the electrons carrying currents have high enough drift velocity, waves are generated. Waves play an important role in the overall dynamics of the plasmasphere by influencing its transport properties. Particularly, they are key to understand the way mass and energy are transferred from the magneto tail to the plasmasphere, the ionosphere and finally to the atmosphere. They also act as a useful diagnostic tool of the plasma state and the relevant physical processes. The plasmasphere sandwiched between the ionosphere and the outer magnetosphere is populated by up flow of ionospheric cold (~1 eV) and dense plasma along geomagnetic field lines. Small scale waves can dissipate energy and influence the thermal state of the plasmasphere, whereas large scale waves can reflect the global morphology of the plasmasphere. Observations from various instruments onboard IMAGE and CLUSTER spacecrafts have made significant advances in our understanding of plasma density irregularities, plume formation, erosion and refilling of the plasmasphere, presence of thermal structures in the plasmasphere and existence of radiation belts. Both missions can be seen as a step forward in our understanding of these phenomena. Recently, Van Allen Probe spacecraft is working to understand the dynamics of plasma waves to improve predictions of space weather which can have damaging effects on satellites and telecommunications signals. Further, Van Allen Probe spacecraft, using its instrument called EMFISIS (Electric and Magnetic Field Instrument Suite and Integrated Science) have measured electric and magnetic waves as they circle the Earth. As the spacecraft encounter a wave, sensors record the changes in the frequency of the electric and magnetic fields. By understanding how waves and particles interact, we can learn how electrons are accelerated and lost from the radiation belts and help protect our satellites and telecommunications in space.