Ground Magnetic Perturbations Associated with Substorms, Pseudo-Breakups, Auroral Streamers and Omega Bands
Abstract
Strong magnetic perturbations on the ground are a prime cause of Geomagnetically-Induced Currents (GICs) that can have catastrophic effects on a number of engineered technological systems like power grids, communication lines, railways, and pipelines. In recent years we have learned that the strongest dB/dt signals may be confined to relatively localized regions. We also know that a number of localized auroral phenomena occur during highly disturbed intervals including substorms, pseudo-breakups, auroral streamers, torches and omega bands. Here we examine which of these types of disturbances are most related to the localized dB/dt signals associated with harmful GIC events. Preliminary results indicate that many of the auroral disturbances are capable of producing strong, localized dB/dt. However, during storms and long-lived substorms, the repetitive quasi-periodic evolution of PBIs into streamers, torches and omega bands has the potential to result in sustained long-lived production of strong localized dB/dt. A major implication of this finding is that we need to be able to model flow bursts in the tail in a reasonable way in order to capture much of the strong localized dB/dt activity during storms and substorms.
- Publication:
-
42nd COSPAR Scientific Assembly
- Pub Date:
- July 2018
- Bibcode:
- 2018cosp...42E1432H