Deciphering the Earth’s Magnetospheric “Zebra Stripes”: Recent Advances and Perspectives

Abstract:

Stripes reminiscent of a zebra’s are usually apparent in the high-resolution energy spectrograms of energetic (tens to hundreds of keV) electrons trapped in the Earth’s inner radiation belt and slot region (below L = 3 approximately). The NASA Van Allen Probes mission has provided unprecedented amounts of high quality data on near-equatorial electric fields and energetic particle fluxes, enabling systematic empirical analyses of the generation, structure and evolution of the “zebra stripes”.

The objective of this presentation is to demonstrate that the “zebra stripes” are far from trivial features of the Earth’s inner belt and slot region. In fact, the “zebra stripes” convey a wealth of valuable scientific information to decipher on the dynamics of the Earth’s inner magnetosphere. In particular, we show how the “zebra stripes” shed light on the timing and amplitude of radial displacements of geomagnetically trapped particles and subauroral electric field variations.

In addition, the recent discovery of “Earth-like zebra stripes” at Saturn suggests that the methods developed for the Earth’s “zebra stripes” likely constitute a benchmark to inform radiation belt physics at other planets.