<Mini-review>Evolution of electron zebra stripes in the Earth's inner magnetosphere

Abstract

We focus on the charged particle in space that exhibits a complex interaction under the influence of the Earth's magnetic field. For certain conditions, these charged particles may get trapped into the Earth's magnetosphere and execute distinct periodic motion unless an external perturbation acts on it. The external perturbation affects the trajectory of the charged particles and leads to the redistribution of their configuration in the space. The energetic particles with energies ranging from 100 keV to a few MeV are trapped in about 1-7 RE forming a doughnut-like two-belt structure namely: (i) the inner radiation belt which is located at about --1-2.5 RE and (ii) the outer radiation belt which is located at about 3-7 RE. The inner belt mainly consists of protons and is relatively stable, while the outer belt is highly dynamic with relativistic electrons. The region between the inner and outer belt is generally devoid of energetic charged particles and is named as slot region. The outer belt electrons continuously decay and reform with each reformed belt may have different physical properties and intensities. The energy versus L-value spectrum of electrons in the inner belt was previously expected to be monotonic and smooth. Later, multi-peaked structures of electron intensities are observed in the energy spectra at L<3. The peak-to-valley ratio of the intensities was observed to reach 10 times or more. Currently, we are testing plausible global mechanisms for the formation of such structures and their variation that could be responsible to alter the magnetic field configuration in the inner magnetosphere down to L = 1.1.