TitleDynamical Properties of Peak and Time‐Integrated Geomagnetic Events Inferred From Sample Entropy
Publication TypeJournal Article
Year of Publication2020
AuthorsMourenas, D, Artemyev, AV, Zhang, X‐J
JournalJournal of Geophysical Research: Space Physics
Volume125
Issue2
Date Published02/2020
ISSN2169-9380
KeywordsDynamical complexity; Entropy; geomagnetic indices; Geomagnetic storms; Solar wind magnetosphere coupling
Abstract

We provide a comprehensive statistical analysis of the sample entropy of peak and time‐integrated geomagnetic events in 2001–2017, considering different measures of event strength, different geomagnetic indices, and a simplified solar wind‐magnetosphere coupling function urn:x-wiley:jgra:media:jgra55526:jgra55526-math-0001. Our investigations reveal the existence of significant correlations between the entropies of urn:x-wiley:jgra:media:jgra55526:jgra55526-math-0002, urn:x-wiley:jgra:media:jgra55526:jgra55526-math-0003, and urn:x-wiley:jgra:media:jgra55526:jgra55526-math-0004, and between such entropies and event strengths, as well as good correlations between peak levels of solar wind‐magnetosphere coupling and ring current ( urn:x-wiley:jgra:media:jgra55526:jgra55526-math-0005) and urn:x-wiley:jgra:media:jgra55526:jgra55526-math-0006 entropies, suggesting a potential predictability of significant urn:x-wiley:jgra:media:jgra55526:jgra55526-math-0007 and urn:x-wiley:jgra:media:jgra55526:jgra55526-math-0008 events on the basis of appropriate functions of urn:x-wiley:jgra:media:jgra55526:jgra55526-math-0009. Sensibly weaker correlations are found with urn:x-wiley:jgra:media:jgra55526:jgra55526-math-0010 entropy. We further show the presence of several significant entropy correlations between geomagnetic indices, solar wind‐magnetosphere coupling, and trapped or precipitated energetic electron and ion fluxes measured by geostationary and low Earth orbit satellites in the outer radiation belt during the same periods. Entropy correlations between urn:x-wiley:jgra:media:jgra55526:jgra55526-math-0011 and trapped or precipitated 30‐ to 80‐keV ion fluxes at low urn:x-wiley:jgra:media:jgra55526:jgra55526-math-0012 and between urn:x-wiley:jgra:media:jgra55526:jgra55526-math-0013 and trapped 40‐keV electron fluxes at geostationary orbit correspond well with ring current properties and substorm‐induced injections, respectively. Entropy correlations between urn:x-wiley:jgra:media:jgra55526:jgra55526-math-0014 and precipitation rates of energetic ion and electron fluxes demonstrate the sensibility of urn:x-wiley:jgra:media:jgra55526:jgra55526-math-0015 index entropy to both low‐energy (5–30 keV) electron injections and ring current. The stronger entropy correlation between solar wind‐magnetosphere coupling and urn:x-wiley:jgra:media:jgra55526:jgra55526-math-0016 than urn:x-wiley:jgra:media:jgra55526:jgra55526-math-0017 likely stems from the more stochastic behavior of electron injections and fast losses near geostationary orbit.

URLhttps://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2019JA027599
DOI10.1029/2019JA027599
Short TitleJ. Geophys. Res. Space Physics


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