University of Warwick | 2019 Jun 21
Magnetic disturbances caused by phenomena like the northern lights can be tracked by a ‘social network’ of ground-based instruments, according to a new study from the University of Warwick.Auroral Substorm from the Polar Spacecraft (1997) Credit: NASA/GSFC/SVSClick to play embedded YouTube video.
The researchers, led by Professor Sandra Chapman, have for the first time characterised the observations from over 100 ground based magnetometers in terms of a time-varying directed network of connections. They monitored the development of geomagnetic substorms using the same mathematics used to study social networks. The magnetometers ‘befriend’ one another when they see the same signal of a propagating disturbance. ...
Using over 100 magnetometers that form the SuperMAG Initiative led by Dr Jesper Gjerloev, the researchers used the mathematical concepts from network science to monitor the development of substorms in the arctic auroral region. As a substorm develops and the electrical current in the ionosphere grows, individual magnetometers will register a change in the magnetic field. Pairs of magnetometers became linked when their measurements correlated with each other, expanding their network of ‘friends’ and allowing the researchers to monitor how the auroral disturbance from the substorm forms and propagates, and how quickly. ...
Directed Network of Substorms Using SuperMAG Ground-Based Magnetometer Data ~ L. Orr, S. C. Chapman, J. W. Gjerloev
- Geophysical Research Letters (online 10 Jun 2019) DOI: 10.1029/2019GL082824