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Critical finite‐size scaling of energy and lifetime probability distributions of auroral emissions
Author(s) -
Uritsky V. M.,
Klimas A. J.,
Vassiliadis D.
Publication year - 2006
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2005gl025330
Subject(s) - substorm , scaling , physics , statistical physics , scale invariance , earth's magnetic field , scale (ratio) , spacecraft , magnetosphere , geophysics , computational physics , magnetic field , quantum mechanics , mathematics , geometry , astronomy
Based on statistical study of approximately 15,500 ultraviolet images of auroral emission regions provided by the UVI experiment on the POLAR spacecraft, we show that energy and duration probability distributions of particle precipitation events obey finite‐size scaling relations indicative of a self‐organized critical (SOC) dynamical state. The revealed relations are invariant with respect to significant changes in the spatial scale of the emission areas, and involve a set of mutually consistent critical exponents providing a quantitative basis for future theoretical studies of multiscale magnetospheric fluctuations. The reported statistical results highlight the importance of cross‐scale coupling in the development of nighttime geomagnetic disturbances and suggest that various manifestations of substorm activity associated with localized magnetic reconnections in the magnetotail (small to large scale substorms, pseudo‐breakups, BBFs and other types of short‐term localized excitations) can be coordinated on the global scale by universal dynamical principle represented by scale‐free avalanching in numerical SOC models.