Ion Acceleration at Magnetotail Turbulent Plasma Jet Fronts
- 1Swedish Institute of Space Physics, Sweden (louisr@irfu.se)
- 2Space and Plasma Physics, Department of Physics and Astronomy, Uppsala University, Sweden
- 3Space and Plasma Physics, School of Electrical Engineering, KTH Royal Institute of Technology, Stockholm, Sweden
- 4The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, USA
- 5Southwest Research Institute, San Antonio, TX, USA
- 6Department of Physics and Astronomy, University of Texas at San Antonio, San Antonio, TX, USA
- 7Department of Earth Planetary and Space Sciences, University of California Los Angeles, Los Angeles, CA, USA
- 8NASA Goddard Space Flight Center, Greenbelt, MD, USA
We investigate a series of Earthward bursty bulk flows (BBFs) observed by the Magnetospheric Multiscale (MMS) spacecraft in the Earth’s magnetotail (X ~ -24 Re, Y ~ 7 Re, Z ~ 4 Re). At the leading edges of the BBFs, we observe complex magnetic field structures. In particular, we focus on one which presents a chain of small scale (~0.5 Re) dipolarizations, and another with a large scale (~3.5 Re) dipolarization. Although the two structures have different scales, both of these structures are associated with flux increases of supra-thermal ions (Ki > 100 keV). We investigate the ion acceleration mechanism and its dependence on the mass and charge state. We show that the ions with gyroradii smaller than the scale of the structure are accelerated by the ion bulk flow. We show that whereas in the small-scale structure, ions with gyroradii comparable with the scale of the structure undergo resonance acceleration, the acceleration in the larger-scale structure is more likely due to a spatially limited electric field. In both cases, we discuss the adiabaticity of the acceleration mechanism.
How to cite: Richard, L., Khotyaintsev, Y. V., Graham, D. B., Vaivads, A., Nikoukar, R., Cohen, I. J., Turner, D. L., Fuselier, S. A., Russell, C. T., Giles, B. L., and Lindqvist, P.-A.: Ion Acceleration at Magnetotail Turbulent Plasma Jet Fronts, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-4045, https://doi.org/10.5194/egusphere-egu22-4045, 2022.
