Magnetic storms predicted for Friday have begun

Today is expected to be one of the most challenging, and likely the most challenging, geomagnetic day of the year. The Earth is expected to simultaneously enter the zone of a large coronal hole and withstand the arrival of two plasma clouds ejected by major solar flares that occurred two days ago.

According to ground-based and space-based monitoring, the first point of the day's schedule has been fulfilled. The planet is believed to have entered the plasma flow from the coronal hole several hours ago. Meanwhile, near-Earth space was already disturbed the day before by yesterday's magnetic storms, and the added influence of the hole has pushed the observed solar wind parameters into extreme ranges. Particularly high values are currently being observed for wind speed, reaching 700-800 km/s, compared to normal values of 300-400 km/s. The temperature of the plasma surrounding the Earth has increased by approximately 5-10 times (approximately half a million degrees).

The response of the Earth's magnetosphere is currently quite moderate. Magnetic storms resumed this morning, remaining at low and mid-level G1-G2 levels. However, they will likely develop into strong G3 events within one to two hours. Signs of this, unfortunately, are already being observed.

In any case, everything that's happening is merely a prelude, creating the backdrop for the main event—the arrival of solar plasma clouds. It's highly likely that the first, fastest portions of the solar mass ejections have already reached Earth (a characteristic jump is observed in the wind speed graph) and are now impacting the planet along with the solar wind. The bulk of the plasma will arrive within 24 hours. It's currently unclear how many impacts the planet will ultimately endure. A likely scenario is that the plasma clouds merge into one along the way, and the boundary between them will be indistinguishable.

Preliminary modeling showed that the densest portions of the solar mass ejections will still miss Earth, and only the planet's peripheral regions will be impacted. In this scenario, today's magnetic storms should not exceed the G4 threshold (level 4 on a 5-point scale). If the situation was assessed incorrectly and a frontal impact hits the planet, there is a possibility that the storms will reach the highest level, G5.

It can be noted that with a peripheral impact, the immediate arrival of the main plasma masses, against a background of solar wind parameters already in extreme zones, may be difficult to discern and will result in a gradual increase in the graphs rather than a sharp impact. Models, however, predicted a sharp impact even with grazing passages. We'll see.