Superstorm Gannon destroyed Earth's plasma shield

Photo: depositphotos

Geomagnetic storms are some of the most extreme forms of space weather, created when the Sun sends out bursts of energy and charged particles toward Earth. Solar storms as powerful as Gannon occur once every twenty to twenty-five years.

Research led by Dr. Atsuki Shinbori of Nagoya University collected direct observations during a solar storm and provided a detailed look at how the event compresses Earth's plasmasphere. The results, published in the journal Earth, Planets and Space, show how both the plasmasphere and ionosphere respond during intense solar disturbances. They also provide insights that could improve predictions of satellite outages, GPS and communications problems caused by extreme space weather.

The Arase satellite that captured the plasmasphere collapse was launched in 2016 by the Japan Aerospace Exploration Agency and travels through Earth's plasmasphere, measuring plasma waves and magnetic fields. In 2024, during the Gannon storm, it found itself in an ideal position, providing scientists with the first direct data showing how the plasmasphere can collapse during a solar storm.

The plasmasphere works with Earth's magnetic field to help block harmful charged particles from the Sun and deep space. It is also a natural shield for satellites and is normally 44,000 kilometers above the surface. However, the Gannon superstorm was able to compress it to just 9,600 kilometers. The storm formed after many powerful eruptions on the Sun and released billions of tons of charged particles towards Earth. The plasmasphere compressed in nine hours. The recovery took more than four days, which is the longest recovery time recorded since the Arase satellite began monitoring the region in 2017.

Superstorms are so powerful that they push the aurora borealis towards the equator. During the peak of solar activity, charged particles can move further along the magnetic field lines towards the equator. As a result, auroras have appeared in many unusual places on the planet, which normally occur near the poles.

About an hour after the arrival of superstorm Gannon, charged particles broke through the Earth's upper atmosphere and streamed toward the polar cap. As the storm began to weaken, the plasmasphere began to replenish itself with particles supplied from the ionosphere. The negative storm radically slowed the recovery by altering the atmospheric chemistry and interrupting the supply of particles to the plasmasphere. The connection between negative storms and delayed plasmaspheric recovery has never been more clearly observed.

Source: sciencedaily, Editorial Weathersunshine.com