Friday, January 29, 2021

The Effect On Earth Of A "Perfect" Coronal Mass Ejection: You Don't Want To Know

 From Spaceweather, January 28:

WHAT IF A 'PERFECT CME' HIT EARTH? You've heard of a "perfect storm." But what about a perfect solar storm? A new study just published in the research journal Space Weather considers what might happen if a worst-case coronal mass ejection (CME) hit Earth. Spoiler alert: You might need a backup generator.

For years, researchers have been wondering, what's the worst the sun could do? In 2014, Bruce Tsurutani (JPL) and Gurbax Lakhina (Indian Institute of Geomagnetism) introduced the "Perfect CME." It would be fast, leaving the sun around 3,000 km/s, and aimed directly at Earth. Moreover, it would follow another CME, which would clear the path in front of it, allowing the storm cloud to hit Earth with maximum force.

None of this is fantasy. The Solar and Heliospheric Observatory (SOHO) has observed CMEs leaving the sun at speeds up to 3,000 km/s. And there are many documented cases of one CME clearing the way for another. Perfect CMEs are real.

Using relatively simple calculations, Tsurutani and Lakhina showed that a Perfect CME would reach Earth in only 12 hours, allowing emergency managers little time to prepare, and slam into our magnetosphere at 45 times the local speed of sound. In response to such a shock, there would be a geomagnetic storm perhaps twice as strong as the Carrington Event of 1859. Power grids, GPS and other high-tech services could experience significant outages.

Sounds bad? Turns out it could be worse.....