Modeling Field Line Curvature Scattering Loss of 1–10 MeV Protons During Geomagnetic Storms
The proton radiation belt contains high fluxes of adiabatically trapped protons varying in energy from ∼one to hundreds of megaelectron volts (MeV). At large radial distances, magnetospheric field lines become stretched on the nightside of Earth and exhibit a small radius of curvature RC near the eq...
Published in: | Journal of Geophysical Research: Space Physics |
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Main Authors: | , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
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American Geophysical Union
2024
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Online Access: | http://nora.nerc.ac.uk/id/eprint/537330/ https://nora.nerc.ac.uk/id/eprint/537330/1/JGR%20Space%20Physics%20-%202024%20-%20Lozinski%20-%20Modeling%20Field%20Line%20Curvature%20Scattering%20Loss%20of%201%2010%20MeV%20Protons%20During%20Geomagnetic.pdf https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2023JA032377 |
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ftnerc:oai:nora.nerc.ac.uk:537330 2024-05-19T07:29:44+00:00 Modeling Field Line Curvature Scattering Loss of 1–10 MeV Protons During Geomagnetic Storms Lozinski, Alexander R. Horne, Richard B. Glauert, Sarah A. Kellerman, Adam C. Bortnik, Jacob Claudpierre, Seth G. Manweiler, Jerry W. Spence, Harlan E. 2024-04-23 text http://nora.nerc.ac.uk/id/eprint/537330/ https://nora.nerc.ac.uk/id/eprint/537330/1/JGR%20Space%20Physics%20-%202024%20-%20Lozinski%20-%20Modeling%20Field%20Line%20Curvature%20Scattering%20Loss%20of%201%2010%20MeV%20Protons%20During%20Geomagnetic.pdf https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2023JA032377 en eng American Geophysical Union https://nora.nerc.ac.uk/id/eprint/537330/1/JGR%20Space%20Physics%20-%202024%20-%20Lozinski%20-%20Modeling%20Field%20Line%20Curvature%20Scattering%20Loss%20of%201%2010%20MeV%20Protons%20During%20Geomagnetic.pdf Lozinski, Alexander R. orcid:0000-0002-6508-487X Horne, Richard B. orcid:0000-0002-0412-6407 Glauert, Sarah A. orcid:0000-0003-0149-8608 Kellerman, Adam C.; Bortnik, Jacob; Claudpierre, Seth G.; Manweiler, Jerry W.; Spence, Harlan E. 2024 Modeling Field Line Curvature Scattering Loss of 1–10 MeV Protons During Geomagnetic Storms. Journal of Geophysical Research: Space Physics, 129 (4), e2023JA032377. 16, pp. https://doi.org/10.1029/2023JA032377 <https://doi.org/10.1029/2023JA032377> cc_by_4 Publication - Article PeerReviewed 2024 ftnerc https://doi.org/10.1029/2023JA032377 2024-04-30T23:32:31Z The proton radiation belt contains high fluxes of adiabatically trapped protons varying in energy from ∼one to hundreds of megaelectron volts (MeV). At large radial distances, magnetospheric field lines become stretched on the nightside of Earth and exhibit a small radius of curvature RC near the equator. This leads protons to undergo field line curvature (FLC) scattering, whereby changes to the first adiabatic invariant accumulate as field strength becomes nonuniform across a gyroorbit. The outer boundary of the proton belt at a given energy corresponds to the range of magnetic L shell over which this transition to nonadiabatic motion takes place, and is sensitive to the occurrence of geomagnetic storms. In this work, we first find expressions for nightside equatorial RC and field strength Be as functions of Dst and L* to fit the TS04 field model. We then apply the Tu et al. (2014, https://doi.org/10.1002/2014ja019864) condition for nonadiabatic onset to solve the outer boundary L*, and refine our expression for RC to achieve agreement with Van Allen Probes observations of 1–50 MeV proton flux over the 2014–2018 era. Finally, we implement this nonadiabatic onset condition into the British Antarctic Survey proton belt model (BAS-PRO) to solve the temporal evolution of proton fluxes at L ≤ 4. Compared with observations, BAS-PRO reproduces storm losses due to FLC scattering, but there is a discrepancy in mid-2017 that suggests a ∼5 MeV proton source not accounted for. Our work sheds light on outer zone proton belt variability at 1–10 MeV and demonstrates a useful tool for real-time forecasting. Article in Journal/Newspaper Antarc* Antarctic British Antarctic Survey Natural Environment Research Council: NERC Open Research Archive Journal of Geophysical Research: Space Physics 129 4 |
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Open Polar |
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Natural Environment Research Council: NERC Open Research Archive |
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ftnerc |
language |
English |
description |
The proton radiation belt contains high fluxes of adiabatically trapped protons varying in energy from ∼one to hundreds of megaelectron volts (MeV). At large radial distances, magnetospheric field lines become stretched on the nightside of Earth and exhibit a small radius of curvature RC near the equator. This leads protons to undergo field line curvature (FLC) scattering, whereby changes to the first adiabatic invariant accumulate as field strength becomes nonuniform across a gyroorbit. The outer boundary of the proton belt at a given energy corresponds to the range of magnetic L shell over which this transition to nonadiabatic motion takes place, and is sensitive to the occurrence of geomagnetic storms. In this work, we first find expressions for nightside equatorial RC and field strength Be as functions of Dst and L* to fit the TS04 field model. We then apply the Tu et al. (2014, https://doi.org/10.1002/2014ja019864) condition for nonadiabatic onset to solve the outer boundary L*, and refine our expression for RC to achieve agreement with Van Allen Probes observations of 1–50 MeV proton flux over the 2014–2018 era. Finally, we implement this nonadiabatic onset condition into the British Antarctic Survey proton belt model (BAS-PRO) to solve the temporal evolution of proton fluxes at L ≤ 4. Compared with observations, BAS-PRO reproduces storm losses due to FLC scattering, but there is a discrepancy in mid-2017 that suggests a ∼5 MeV proton source not accounted for. Our work sheds light on outer zone proton belt variability at 1–10 MeV and demonstrates a useful tool for real-time forecasting. |
format |
Article in Journal/Newspaper |
author |
Lozinski, Alexander R. Horne, Richard B. Glauert, Sarah A. Kellerman, Adam C. Bortnik, Jacob Claudpierre, Seth G. Manweiler, Jerry W. Spence, Harlan E. |
spellingShingle |
Lozinski, Alexander R. Horne, Richard B. Glauert, Sarah A. Kellerman, Adam C. Bortnik, Jacob Claudpierre, Seth G. Manweiler, Jerry W. Spence, Harlan E. Modeling Field Line Curvature Scattering Loss of 1–10 MeV Protons During Geomagnetic Storms |
author_facet |
Lozinski, Alexander R. Horne, Richard B. Glauert, Sarah A. Kellerman, Adam C. Bortnik, Jacob Claudpierre, Seth G. Manweiler, Jerry W. Spence, Harlan E. |
author_sort |
Lozinski, Alexander R. |
title |
Modeling Field Line Curvature Scattering Loss of 1–10 MeV Protons During Geomagnetic Storms |
title_short |
Modeling Field Line Curvature Scattering Loss of 1–10 MeV Protons During Geomagnetic Storms |
title_full |
Modeling Field Line Curvature Scattering Loss of 1–10 MeV Protons During Geomagnetic Storms |
title_fullStr |
Modeling Field Line Curvature Scattering Loss of 1–10 MeV Protons During Geomagnetic Storms |
title_full_unstemmed |
Modeling Field Line Curvature Scattering Loss of 1–10 MeV Protons During Geomagnetic Storms |
title_sort |
modeling field line curvature scattering loss of 1–10 mev protons during geomagnetic storms |
publisher |
American Geophysical Union |
publishDate |
2024 |
url |
http://nora.nerc.ac.uk/id/eprint/537330/ https://nora.nerc.ac.uk/id/eprint/537330/1/JGR%20Space%20Physics%20-%202024%20-%20Lozinski%20-%20Modeling%20Field%20Line%20Curvature%20Scattering%20Loss%20of%201%2010%20MeV%20Protons%20During%20Geomagnetic.pdf https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2023JA032377 |
genre |
Antarc* Antarctic British Antarctic Survey |
genre_facet |
Antarc* Antarctic British Antarctic Survey |
op_relation |
https://nora.nerc.ac.uk/id/eprint/537330/1/JGR%20Space%20Physics%20-%202024%20-%20Lozinski%20-%20Modeling%20Field%20Line%20Curvature%20Scattering%20Loss%20of%201%2010%20MeV%20Protons%20During%20Geomagnetic.pdf Lozinski, Alexander R. orcid:0000-0002-6508-487X Horne, Richard B. orcid:0000-0002-0412-6407 Glauert, Sarah A. orcid:0000-0003-0149-8608 Kellerman, Adam C.; Bortnik, Jacob; Claudpierre, Seth G.; Manweiler, Jerry W.; Spence, Harlan E. 2024 Modeling Field Line Curvature Scattering Loss of 1–10 MeV Protons During Geomagnetic Storms. Journal of Geophysical Research: Space Physics, 129 (4), e2023JA032377. 16, pp. https://doi.org/10.1029/2023JA032377 <https://doi.org/10.1029/2023JA032377> |
op_rights |
cc_by_4 |
op_doi |
https://doi.org/10.1029/2023JA032377 |
container_title |
Journal of Geophysical Research: Space Physics |
container_volume |
129 |
container_issue |
4 |
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1799481156311187456 |