Storm-time dynamics of ring current protons: Implications for the long-term energy budget in the inner magnetosphere

TitleStorm-time dynamics of ring current protons: Implications for the long-term energy budget in the inner magnetosphere
Publication TypeJournal Article
Year of Publication2016
AuthorsGkioulidou, M, Ukhorskiy, A, Mitchell, DG, Lanzerotti, LJ
JournalGeophysical Research Letters
Paginationn/a - n/a
Date Published05/2016
Keywordsenergy budget; Geomagnetic storms; inner magnetosphere; ring current; Van Allen Probes
AbstractOur investigation of the long-term ring current proton pressure evolution in Earth's inner magnetosphere based on Van Allen Probes data shows drastically different behavior of the low- and high- energy components of the ring current proton population with respect to theSYM-H index variation. We found that while the low-energy component of the protons (<80‚ÄČkeV) is strongly governed by convective timescales and is very well correlated with the absolute value of SYM-H index, the high-energy component (>100‚ÄČkeV) varies on much longer timescales and shows either no correlation or anticorrelation with the absolute value of SYM-H index. Our study also shows that the contributions of the low- and high- energy protons to the inner magnetosphere energy content are comparable. Thus, our results conclusively demonstrate that proton dynamics, and as a result the energy budget in the inner magnetosphere, do not vary strictly on storm time timescales as those are defined by the SYM-H index.
URLhttp://doi.wiley.com/10.1002/2016GL068013
DOI10.1002/2016GL068013
Short TitleGeophys. Res. Lett.


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