Build-up of Earth’s storm-time ring current via mesoscale plasma sheet flows
| Autor: | Sciola, A., Merkin, S., Sorathia, K., Gkioulidou, M., Bao, S., Toffoletto, F., Michael, A., Pham, K., Lin, D., Wiltberger, M., Ukhorskiy, S. |
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| Rok vydání: | 2023 |
| Zdroj: | XXVIII General Assembly of the International Union of Geodesy and Geophysics (IUGG) |
| DOI: | 10.57757/iugg23-4196 |
| Popis: | A major component of Earth’s response to geomagnetic storms is the formation of the ring current, which drives the Region 2 current system and whose energy spectrum influences the storm recovery rate and ionospheric conductance driven by magnetospheric precipitation. While it is well understood that the primary source of this population is plasma transported from the tail plasma sheet, the relative roles of global-scale convection and mesoscale bursty bulk flows (BBFs) in this transport remain unclear, despite many observational and numerical studies. To address this fundamental question, we present an investigation of the March 17th, 2013 storm using the Multiscale Atmosphere Geospace Environment (MAGE) model, developed by the NASA Drive Science Center for Geospace Storms (CGS), and quantify the contribution of plasma transported by BBFs/entropy-depleted bubbles to the inner magnetosphere. In particular, we show that they are responsible for at least half of the energy density enhancement within 6 Re. Comparison between the modeled proton intensities to those observed by the Van Allen Probes show that the model accurately reproduces the bulk and spectral properties of the storm-time ring current. Analysis of the evolution of the ring current energy spectra throughout the storm finds that this evolution is driven by both an evolving plasma sheet population and by energy-dependent charge exchange. Reproducing not just the bulk properties but also the energy spectra is critical to modeling, from first principles, the complex coupling between the ring current and the ionosphere, exosphere, and the geospace system as a whole. The 28th IUGG General Assembly (IUGG2023) (Berlin 2023) |
| Databáze: | OpenAIRE |
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