Cheng, I;
Achilleos, N;
Masters, A;
Lewis, G;
Kane, M;
Guio, P;
(2021)
Electron Bulk Heating at Saturn's Magnetopause.
Journal of Geophysical Research: Space Physics
, 126
(5)
, Article e2020JA028800. 10.1029/2020ja028800.
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Abstract
Magnetic reconnection at the magnetopause (MP) energises ambient plasma via the release of magnetic energy and produces an “open” magnetosphere allowing solar wind particles to directly enter the system. At Saturn, the nature of MP reconnection remains unclear. The current study examines electron bulk heating at MP crossings, in order to probe the relationship between observed and predicted reconnection heating proposed by Phan et al. (2013) under open and closed MP, and how this may pertain to the position of the crossings in the Δβ‐magnetic shear parameter space. The electron heating for 70 MP crossings made by the Cassini spacecraft from April 2005 to July 2007 was found using 1d and 3d moment methods. Minimum variance analysis was used on the magnetic field data to help indicate whether the MP is open or closed. We found better agreement between observed and predicted heating for events suggestive of locally ‘open’ MP. For events suggestive of locally ‘closed’ MP, we observed a cluster of points consistent with no electron heating, but also numerous cases with significant heating. Examining the events in the Δβ‐magnetic shear parameter space, we find 83% of events without evidence of energisation were situated in the ‘reconnection suppressed’ regime, whilst between 43% to 68% of events with energisation lie in the ‘reconnection possible’ regime depending on the threshold used. The discrepancies could be explained by a combination of spatial and temporal variability which makes it possible to observe heated electrons with different conditions from the putative reconnection site.
| Type: | Article |
|---|---|
| Title: | Electron Bulk Heating at Saturn's Magnetopause |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1029/2020ja028800 |
| Publisher version: | https://doi.org/10.1029/2020ja028800 |
| Language: | English |
| Additional information: | © 2021. The Authors. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Space and Climate Physics |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10125311 |
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