EGU2020-8550, updated on 08 Jan 2024
https://doi.org/10.5194/egusphere-egu2020-8550
EGU General Assembly 2020
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

Energy conversion by electron beam-driven waves in a compressed reconnection separatrix

Justin Holmes, Rumi Nakamura, Owen Roberts, Daniel Schmid, Takuma Nakamura, and Zoltan Vörös
Justin Holmes et al.
  • Institut für Weltraumforschung, Graz, Austria (justin.holmes@oeaw.ac.at)

We investigate magnetic compression near the reconnection separatrix observed by Magnetospheric MultiScale (MMS) on July 11th 2017. A clear transition between inflow and outflow in both ions and electrons is observed across an ion gyro-scale region of enhanced magnetic field. Multispacecraft techniques for magnetic curvature and local gradients along with timing of highly-correlated wave packets are used to determine the spatial configuration of the compressed region. Structure of the system is found to be inherently three dimensional; electron beam-driven modes propagating parallel to the magnetic field are observed concurrent with perpendicular-propagating lower hybrid waves. Larger scale surface waves are also present behind the compression front. Transforming to a deHoffmann-Teller frame across the boundary results in a distinctly non-rotational discontinuity with structure similar to a quasi-2D, Petschek-like slow shock. However, MHD jump conditions are not satisfied, indicating kinetic dissipation may occur within the thin layer. The largest amplitude measurements of $\mathbf{J}\cdot\mathbf{E}$ energy conversion are associated with an inflowing electron beam and parallel electric fields near the magnetic peak. Spikes in $\mathbf{J}\cdot\mathbf{E}$ are predominantly negative, suggesting electron-scale mixing between the reconnection inflow and outflow is partially responsible for the observed magnetic compression.

How to cite: Holmes, J., Nakamura, R., Roberts, O., Schmid, D., Nakamura, T., and Vörös, Z.: Energy conversion by electron beam-driven waves in a compressed reconnection separatrix, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-8550, https://doi.org/10.5194/egusphere-egu2020-8550, 2020.

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