The solar eruptive event in July 2012: Examining extreme space weather scenarios
Abstract
A key goal for space weather studies is to define extreme conditions that might plausibly afflict human technology. On 23 July 2012, an immense solar active region gave rise to a powerful coronal mass ejection (CME) with an initial speed that was determined to be over 2500 km/s. The eruption was directed away from Earth toward the NASA STEREO-A spacecraft. The satellite sensors detected the CME arrival 19 h later and made in situ measurements of the solar wind and interplanetary magnetic field. In prior work, we have addressed the question of what would have happened if this powerful interplanetary event had been Earthward directed. We found that the 23-24 July event would certainly have produced a geomagnetic storm that was comparable to the largest events of the twentieth century (Dst -500 nT). Using plausible assumptions, the most extreme modeled value of storm-time disturbance would have been Dst -1200 nT. This is considerably larger than estimates for the famous Carrington storm of 1859. This finding has far reaching implications because it demonstrates that extreme space weather conditions such as those during March of 1989 or September of 1859 can happen even during a modest solar activity cycle such as the one presently underway. We have argued that this July 2012 extreme event should be widely employed by the space weather community to model extreme space weather effects on technological systems such as the electric power grid, and other human technology systems. We consider what such an event hitting Earth would do to modern infrastructure.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFMPA13E..01L
- Keywords:
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- 4305 Space weather;
- NATURAL HAZARDSDE: 7954 Magnetic storms;
- SPACE WEATHERDE: 7964 Policy;
- SPACE WEATHERDE: 7974 Solar effects;
- SPACE WEATHER