Forsyth, C;
Rae, IJ;
Murphy, K;
Freeman, M;
Huang, C-L;
Spence, H;
Boyd, A;
... Watt, C; + view all
(2016)
What effect do substorms have on the content of the radiation belts?
Journal of Geophysical Research: Space Physics
, 121
(7)
pp. 6292-6306.
10.1002/2016JA022620.
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Abstract
Substorms are fundamental and dynamic processes in the magnetosphere, converting captured solar wind magnetic energy into plasma energy. These substorms have been suggested to be a key driver of energetic electron enhancements in the outer radiation belts. Substorms inject a keV “seed” population into the inner magnetosphere which is subsequently energized through wave-particle interactions up to relativistic energies; however, the extent to which substorms enhance the radiation belts, either directly or indirectly, has never before been quantified. In this study, we examine increases and decreases in the total radiation belt electron content (TRBEC) following substorms and geomagnetically quiet intervals. Our results show that the radiation belts are inherently lossy, shown by a negative median change in TRBEC at all intervals following substorms and quiet intervals. However, there are up to 3 times as many increases in TRBEC following substorm intervals. There is a lag of 1–3 days between the substorm or quiet intervals and their greatest effect on radiation belt content, shown in the difference between the occurrence of increases and losses in TRBEC following substorms and quiet intervals, the mean change in TRBEC following substorms or quiet intervals, and the cross correlation between SuperMAG AL (SML) and TRBEC. However, there is a statistically significant effect on the occurrence of increases and decreases in TRBEC up to a lag of 6 days. Increases in radiation belt content show a significant correlation with SML and SYM-H, but decreases in the radiation belt show no apparent link with magnetospheric activity levels.
| Type: | Article |
|---|---|
| Title: | What effect do substorms have on the content of the radiation belts? |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1002/2016JA022620 |
| Publisher version: | http://dx.doi.org/10.1002/2016JA022620 |
| Language: | English |
| Additional information: | Copyright © 2016. 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. Further details about CC BY licenses are available at http://creativecommons.org/licenses/by/4.0 |
| Keywords: | Radiation belts, Magnetic storms and substorms, Substorms, substorm, radiation belts, enhancements, losses |
| 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 Space and Climate Physics |
| URI: | https://discovery.ucl.ac.uk/id/eprint/1502161 |
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