Chorus wave power at the strong diffusion limit overcomes electron losses due to strong diffusion
Abstract Earth’s radiation belts consist of high-energy charged particles trapped by Earth’s magnetic field. Strong pitch angle diffusion of electrons caused by wave-particle interaction in Earth’s radiation belts has primarily been considered as a loss process, as trapped electrons are rapidly diff...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Nature Portfolio
2024-02-01
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| Series: | Nature Communications |
| Online Access: | https://doi.org/10.1038/s41467-024-45967-9 |
| _version_ | 1827326799576563712 |
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| author | T. A. Daggitt R. B. Horne S. A. Glauert G. Del Zanna J. M. Albert |
| author_facet | T. A. Daggitt R. B. Horne S. A. Glauert G. Del Zanna J. M. Albert |
| author_sort | T. A. Daggitt |
| collection | DOAJ |
| description | Abstract Earth’s radiation belts consist of high-energy charged particles trapped by Earth’s magnetic field. Strong pitch angle diffusion of electrons caused by wave-particle interaction in Earth’s radiation belts has primarily been considered as a loss process, as trapped electrons are rapidly diffused into the loss cone and lost to the atmosphere. However, the wave power necessary to produce strong diffusion should also produce rapid energy diffusion, and has not been considered in this context. Here we provide evidence of strong diffusion using satellite data. We use two-dimensional Fokker-Planck simulations of electron diffusion in pitch angle and energy to show that scaling up chorus wave power to the strong diffusion limit produces rapid acceleration of electrons, sufficient to outweigh the losses due to strong diffusion. The rate of losses saturates at the strong diffusion limit, whilst the rate of acceleration does not. This leads to the surprising result of an increase, not a decrease in the trapped electron population during strong diffusion due to chorus waves as expected when treating strong diffusion as a loss process. Our results suggest there is a tipping point in chorus wave power between net loss and net acceleration that global radiation belt models need to capture to better forecast hazardous radiation levels that damage satellites. |
| first_indexed | 2024-03-07T14:51:48Z |
| format | Article |
| id | doaj.art-a291793a35ff4b9a8ed0b3586ce53108 |
| institution | Directory Open Access Journal |
| issn | 2041-1723 |
| language | English |
| last_indexed | 2024-03-07T14:51:48Z |
| publishDate | 2024-02-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Nature Communications |
| spelling | doaj.art-a291793a35ff4b9a8ed0b3586ce531082024-03-05T19:41:32ZengNature PortfolioNature Communications2041-17232024-02-011511810.1038/s41467-024-45967-9Chorus wave power at the strong diffusion limit overcomes electron losses due to strong diffusionT. A. Daggitt0R. B. Horne1S. A. Glauert2G. Del Zanna3J. M. Albert4British Antarctic SurveyBritish Antarctic SurveyBritish Antarctic SurveyDepartment of Applied Maths and Theoretical Physics, University of CambridgeAir Force Research LaboratoryAbstract Earth’s radiation belts consist of high-energy charged particles trapped by Earth’s magnetic field. Strong pitch angle diffusion of electrons caused by wave-particle interaction in Earth’s radiation belts has primarily been considered as a loss process, as trapped electrons are rapidly diffused into the loss cone and lost to the atmosphere. However, the wave power necessary to produce strong diffusion should also produce rapid energy diffusion, and has not been considered in this context. Here we provide evidence of strong diffusion using satellite data. We use two-dimensional Fokker-Planck simulations of electron diffusion in pitch angle and energy to show that scaling up chorus wave power to the strong diffusion limit produces rapid acceleration of electrons, sufficient to outweigh the losses due to strong diffusion. The rate of losses saturates at the strong diffusion limit, whilst the rate of acceleration does not. This leads to the surprising result of an increase, not a decrease in the trapped electron population during strong diffusion due to chorus waves as expected when treating strong diffusion as a loss process. Our results suggest there is a tipping point in chorus wave power between net loss and net acceleration that global radiation belt models need to capture to better forecast hazardous radiation levels that damage satellites.https://doi.org/10.1038/s41467-024-45967-9 |
| spellingShingle | T. A. Daggitt R. B. Horne S. A. Glauert G. Del Zanna J. M. Albert Chorus wave power at the strong diffusion limit overcomes electron losses due to strong diffusion Nature Communications |
| title | Chorus wave power at the strong diffusion limit overcomes electron losses due to strong diffusion |
| title_full | Chorus wave power at the strong diffusion limit overcomes electron losses due to strong diffusion |
| title_fullStr | Chorus wave power at the strong diffusion limit overcomes electron losses due to strong diffusion |
| title_full_unstemmed | Chorus wave power at the strong diffusion limit overcomes electron losses due to strong diffusion |
| title_short | Chorus wave power at the strong diffusion limit overcomes electron losses due to strong diffusion |
| title_sort | chorus wave power at the strong diffusion limit overcomes electron losses due to strong diffusion |
| url | https://doi.org/10.1038/s41467-024-45967-9 |
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