Intense chorus waves result in the limitation of electron fluxes in the heart of the outer radiation belt
| Autor: | Chakraborty, S., Mann, I., Watt, C., Rae, J., Olifer, L., Ozeke, L., Sandhu, J., Mauk, B., Spence, H. |
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| Rok vydání: | 2023 |
| Zdroj: | XXVIII General Assembly of the International Union of Geodesy and Geophysics (IUGG) |
| DOI: | 10.57757/iugg23-2025 |
| Popis: | In this study, using 7 years of Van Allen Probes electron flux and chorus wave measurements, we show a new and distinct population of very intense chorus waves that are generated in the heart of the outer radiation belt (L* = 4 - 6) during the main phase of geomagnetic storms. During 70 isolated geomagnetic storms in the entire Van Allen Probe era (2012 - 2019), we found that during the storm main phase, the power of choruswaves increases by ~2 - 3 orders of magnitude above the pre-storm levels when the fluxes of ~10 - 100 keV electrons approach or exceed a certain energy-dependent flux value theoretically predicted by Kennel and Petschek (KP) more than 50 years ago. In the original KP theory, it was predicted that at the limit, it is the intense chorus waves that scatter electrons into the loss cone preventing any further increase of flux, thereby maintaining the flux at the limit. In this study, we further used POES electron flux data to show that the precipitating flux indeed increases during the storm main phase in a similar manner as predicted in the original KP theory. We also investigated the properties of these intense chorus waves. Our results thus have a very crucial impact on the understanding of the dynamics of the Van Allen radiation belts and in future, these results can be implemented in radiation belt models to study the impact of the high-intensity chorus waves on the radiation belt electron population. The 28th IUGG General Assembly (IUGG2023) (Berlin 2023) |
| Databáze: | OpenAIRE |
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