Space weather events power auroras and threaten power grids

Solar storms trigger substorms

A coronal mass ejection from the sun releases a cloud of charged particles and magnetic fields toward Earth. When this cloud reaches our planet, its magnetic field connects with Earth's magnetosphere on the sun-facing side. The solar wind then stretches these connected field lines far into space behind Earth to form the magnetotail. Energy builds up in this tail until it reconnects explosively in a process called a substorm. This release happens roughly 28000 to 40000 miles from Earth on the side facing away from the sun.

Particles create lights and currents

During the substorm, energetic particles shoot along magnetic field lines directly toward Earth's surface. In the upper atmosphere, these particles crash into oxygen and nitrogen atoms situated between 56 and 93 miles high. Such collisions produce the glowing aurora visible as green or red curtains rippling across the night sky. The same energetic particles also drive strong electrical currents within Earth's upper atmosphere that change rapidly. Rapid changes in these currents cause Earth's magnetic field at ground level to shift sharply.

Ground currents damage transformers

These changing magnetic fields induce electric currents flowing through the ground beneath your feet and into power lines. Such induced currents can potentially damage large transformers and trip circuit breakers across the grid. The strength of this impact varies depending on local latitude and the structure of soil or rock below. Space physicists study these connections to understand how space weather affects infrastructure on Earth today.