Found 5 entries in the Bibliography.
Showing entries from 1 through 5
| 2021 |
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The Roles of the Magnetopause and Plasmapause in Storm-Time ULF Wave Power Enhancements Abstract Ultra Low Frequency (ULF) waves play a crucial role in transporting and coupling energy within the magnetosphere. During geomagnetic storms, dayside magnetospheric ULF wave power is highly variable with strong enhancements that are dominated by elevated solar wind driving. However, the radial distribution of ULF wave power is complex - controlled interdependently by external solar wind driving and the internal magnetospheric structuring. We conducted a statistical analysis of observed storm-time ULF wave power from ... Sandhu, J.; Rae, I.; Staples, F.; Hartley, D.; Walach, M.-T.; Elsden, T.; Murphy, K.; YEAR: 2021 DOI: https://doi.org/10.1029/2021JA029337 ULF waves; Geomagnetic storms; Van Allen Probes; radial diffusion; inner magnetosphere; plasmasphere |
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Abstract The impact of radial diffusion in storm time radiation belt dynamics is well-debated. In this study we quantify the changes and variability in radial diffusion coefficients during geomagnetic storms. A statistical analysis of Van Allen Probes data (2012 − 2019) is conducted to obtain measurements of the magnetic and electric power spectral densities for Ultra Low Frequency (ULF) waves, and corresponding radial diffusion coefficients. The results show global wave power enhancements occur during the storm main phase ... Sandhu, J.; Rae, I.; Wygant, J.; Breneman, A.; Tian, S.; Watt, C.; Horne, R.; Ozeke, L.; Georgiou, M.; Walach, M.-T.; YEAR: 2021 DOI: https://doi.org/10.1029/2020JA029024 ULF waves; radial diffusion; outer radiation belt; Van Allen Probes; Geomagnetic storms |
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Challenging the Use of Ring Current Indices During Geomagnetic Storms Abstract The ring current experiences dramatic enhancements during geomagnetic storms, however understanding the global distribution of ring current energy content is restricted by spacecraft coverage. Many studies use ring current indices as a proxy for energy content, but these indices average over spatial variations and include additional contributions. We have conducted an analysis of Van Allen Probes’ data, identifying the spatial distribution and storm-time variations of energy content. Ion observations from the HOPE ... Sandhu, J.; Rae, I.; Walach, M.-T.; YEAR: 2021 DOI: https://doi.org/10.1029/2020JA028423 ring current; Geomagnetic storms; Van Allen Probes; inner magnetosphere; substorms |
| 2019 |
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Substorm-Ring Current Coupling: A Comparison of Isolated and Compound Substorms Substorms are a highly variable process, which can occur as an isolated event or as part of a sequence of multiple substorms (compound substorms). In this study we identify how the low-energy population of the ring current and subsequent energization varies for isolated substorms compared to the first substorm of a compound event. Using observations of H+ and O+ ions (1 eV to 50 keV) from the Helium Oxygen Proton Electron instrument onboard Van Allen Probe A, we determine the energy content of the ring current in L-MLT space ... Sandhu, J.; Rae, I.; Freeman, M.; Gkioulidou, M.; Forsyth, C.; Reeves, G.; Murphy, K.; Walach, M.-T.; YEAR: 2019 DOI: 10.1029/2019JA026766 inner magnetosphere; ring current; substorms; Van Allen; Van Allen Probes |
| 2018 |
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Energisation of the ring current by substorms The substorm process releases large amounts of energy into the magnetospheric system, although where the energy is transferred to and how it is partitioned remains an open question. In this study, we address whether the substorm process contributes a significant amount of energy to the ring current. The ring current is a highly variable region, and understanding the energisation processes provides valuable insight into how substorm - ring current coupling may contribute to the generation of storm conditions and provide a sou ... Sandhu, J.; Rae, I.; Freeman, M.; Forsyth, C.; Gkioulidou, M.; Reeves, G.; Spence, H.; Jackman, C.; Lam, M.; YEAR: 2018 DOI: 10.1029/2018JA025766 BSPICE; HOPE; Magnetosphere; ring current; substorms; Van Allen Probes |
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