THEMIS Observations of Particle Acceleration by a Magnetosheath Jet-Driven Bow Wave
Rami Vainio; Yuri Omelchenko; Heli Hietala; Terry Z. Liu; Vadim Roytershteyn; Vassilis Angelopoulos
THEMIS Observations of Particle Acceleration by a Magnetosheath Jet-Driven Bow Wave
Rami Vainio
Yuri Omelchenko
Heli Hietala
Terry Z. Liu
Vadim Roytershteyn
Vassilis Angelopoulos
American Geophysical Union
Julkaisun pysyvä osoite on:
https://urn.fi/URN:NBN:fi-fe2021042827573
https://urn.fi/URN:NBN:fi-fe2021042827573
Tiivistelmä
Localized magnetosheath jets with high dynamic pressure are frequently observed downstream of Earth's bow shock. When such a fast magnetosheath jet compresses the ambient magnetosheath plasma, an earthward compressional bow wave could form. Such bow waves have been predicted by simulations but have never been observed. Using multipoint Time History of Events and Macroscale Interactions during Substroms (THEMIS) observations, we report the first observation where such a bow wave driven by an intrinsically formed magnetosheath jet can reflect and accelerate particles up to tens of kiloelectron volt for ions and 100 keV for electrons. By analyzing the ion distributions, we infer how particles reach the spacecraft from the bow wave demonstrating good agreement with our model of single particle motion. Our study implies that particle acceleration at magnetosheath jets could contribute significantly to particle acceleration at shocks in general.
Kokoelmat
- Rinnakkaistallenteet [19207]