Scale‐free and scale‐dependent modes of energy release dynamics in the nighttime magnetosphere

[1] Based on a spatiotemporal analysis of POLAR UVI images, we show for the first time that energy, power, area and lifetime probability distributions of electron precipitation events in the nighttime auroral oval have a significant latitudinal dependence. The low-latitude group of the events contains a distinct subpopulation of strong auroral disturbances violating the uniform power-law behavior reported in previous publications, while the high latitude group is described by nearly perfect power-law statistics over the entire range of scales studied, in agreement with earlier findings. The results obtained indicate that the inner and outer portions of the plasma sheet may be characterized by substantially different scaling regimes of bursty energy dissipation suggestive of different universality classes and/or driving conditions associated with multiscale turbulence in these regions.