The Substorms of 26 February 2008: A Data-Mining Perspective

Reconstruction of the magnetospheric magnetic field using swarms of virtual spacecraft provided by data mining confirms seminal in situ evidence (Angelopoulos et al., 2008, https://doi.org/10.1126/science.1160495) that on 26 February 2008 an X-line emerged in the region between two distant Time History of Events and Macroscale Interactions during Substorms probes at the time of the substorm activation in the magnetotail. It also shows that the X-line formation was preceded by rapid current decay that happened 15 min earlier. The current was built up earthward of the pre-existing X-line formed prior to the previous substorm activation 45 min before. The most pronounced effect of the tail reconfiguration at the moments of two substorm activations and the current disruption is the rapid earthward redistribution of the magnetic flux. Comparison of low-altitude mapping of the magnetotail structure with all-sky imager data shows that these rapid reconfigurations might be triggered by plasma flows whose source was farther from the Earth than the resolved X-lines.