Nighttime Magnetic Perturbation Events Observed in Arctic Canada: 2. Multiple‐Instrument Observations
Abstract
The rapid changes of magnetic fields associated with nighttime magnetic perturbations with amplitudes |ΔB| of hundreds of nanoteslas and 5‐ to 10‐min periods can induce bursts of geomagnetically induced currents that can harm technological systems. This paper presents three cases of intervals of intense and complex nighttime magnetic perturbations in eastern Arctic Canada in 2015, augmented by observations from auroral imagers and high‐altitude spacecraft in the nightside magnetosphere. Each case occurred within 1 hr after substorm onsets. None occurred during the main phase of a geomagnetic storm, and only the first during the early recovery phase (of a moderate storm). The cases were similar in that two or three intervals occurred in this region over a span of ~1 hr; these showed a spatial progression, in that successive intervals occurred later at more western and northern stations. During several intervals, individual peak Bx impulses occurred nearly simultaneously (within 1–2 min) at several stations, while during others the impulses occurred later at more western and northern stations, and during one interval they occurred later at southern stations. During both of the cases for which auroral images were available, a westward traveling surge and a poleward auroral expansion and/or poleward boundary intensification occurred, and during two events auroral streamers coincided in time and location with magnetic perturbations. These observations appear to be consistent with several earlier studies connecting nighttime magnetic perturbation events to localized auroral structures and to dipolarizing flux bundles and bursty bulk flows in the magnetotail.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Sep 01, 2019
- Source ID
- 10.1029/2019ja026797
Entities
People
- Andrew N. Fazakerley
- Christopher T. Russell
- D. H. Boteler
- E. S. Steinmetz
- Howard Singer
- Ian R Mann
- J. L. Posch
- J. M. Weygand
- Larry R Lyons
- Lynn Kistler
- Mark B. Moldwin
- Mark Engebretson
- Martin Connors
- Michael Hartinger
- Shinichi Ohtani
- Vyacheslav Pilipenko
- Yukitoshi Nishimura
Organizations
- Air Force Office of Scientific Research
- Athabasca University
- Augsburg University
- Boston University
- Center for Hierarchical Manufacturing
- Johns Hopkins University
- Natural Sciences and Engineering Research Council
- University College London
- University of Alberta
- University of Michigan
- University of New Hampshire
- Virginia Tech
- West Virginia Space Grant Consortium