Geomagnetic storm alert: Solar eruption could trigger G1 storm today

A powerful eruption on the Sun has sent a cloud of magnetized plasma towards Earth, with space weather forecasters expecting the solar material to reach Earth's magnetic field on Monday, 17 August.

The event began on 14 August, when a large magnetic filament erupted from the Sun's surface. The eruption produced a coronal mass ejection (CME) — a massive cloud of charged particles and magnetic fields blasted into space.

Space weather monitoring agencies have been tracking the CME and predict that it could deliver a glancing blow to Earth's magnetic field.

What is G1 geomagnetic storm?

The incoming solar material could trigger a G1-class geomagnetic storm, the lowest category on the US National Oceanic and Atmospheric Administration's five-level storm scale.

A G1 storm is considered minor, but it can still disturb Earth's magnetosphere. Geomagnetic storms occur when charged particles and magnetic fields carried by a CME interact with Earth's magnetic shield.

This interaction can compress the magnetosphere and transfer energy into the upper atmosphere. Depending on the strength of the disturbance, geomagnetic storms can affect satellites, radio communications, navigation systems and, in stronger cases, power infrastructure.

The 17 August event, however, is expected to be relatively modest compared with the more powerful solar storms observed during the active phase of the current solar cycle.

Can Northern Lights become more visible?

One possible consequence of the incoming CME is enhanced auroral activity.

Skywatchers in parts of northern North America and Europe could see brighter or more extensive Northern Lights if the solar material interacts with Earth's magnetic field under favourable conditions.

However, a geomagnetic storm forecast does not guarantee that auroras will be visible from a particular location. Visibility will depend on the storm's actual intensity, the interaction between the solar and Earth's magnetic fields, darkness and local weather conditions.

Why are scientists monitoring Sun?

The latest CME comes as the Sun remains active, producing solar flares, magnetic filament eruptions and Earth-directed coronal mass ejections.

The Sun follows an approximately 11-year cycle of activity, with periods of greater and lower solar activity. During active phases, eruptions that can send charged particles towards Earth become more frequent.

Scientists closely monitor these events because stronger geomagnetic storms can disrupt technologies that modern society relies on, including satellites, communications, navigation and power systems.

Even a relatively minor storm such as the one expected on 17 August can provide researchers with useful information about how Earth's magnetic field responds to solar activity.

For now, no significant impact on the general public is expected from the forecast G1 storm. Space weather experts will continue to track the CME as it approaches Earth and assess the strength of the resulting geomagnetic activity.