Gerry Palmers Science 08.29.2022 22:Aug PM EDT

Solar Flares Cause Radio, Satellite Disruptions, Dazzling Auroras, Minor Threat to Astronauts

High solar activity from Saturday, August 27, to Monday, August 29, led to radio blackouts across North America and dazzling auroras in the Northern Hemisphere.

Solar flares registered their most powerful intensity at a moderate M8-class flare on Monday at 7:07 am EDT (11:07 am GMT), SpaceWeather.com reported. According to NASA, M-class flares, while moderate, can cause brief radio blackouts at the poles and minor radiation storms that threaten the safety of astronauts.

Scientists categorize the intensity of solar flares into five-lettered ranks. Within these ranks, a higher number means greater outbursts.

M4-class Flare Led to Radio Blackouts

On Saturday, the sun also emitted an M4-class flare from sunspot AR3088. SpaceWeather.com added that the flare could spark G1-class geomagnetic storms beginning on August 28 that would stretch into August 29. On Sunday, the site reported that the same sunspot ejected an M6.7-class flare, which led to radio blackouts over much of North America, the site further said.

The sunspot, named AR3085 for the "active region" of the sun in which it appeared, was small as a blip a few days ago. Now, that blip has grown ten times larger, changing into two sunspots that each has the size that nearly matches the diameter of Earth, SpaceWeather.com further said.

A number of solar flares, which are large explosions of electromagnetic radiation that are unleashed from the sun's surface and launched into space, have been observed "crackling" around the AR3085, SpaceWeather.com noted. Fortunately, they are all currently C-class flares, which fit into the weakest of the three tiers of solar flares that government satellites track. A-, B- and C-class flares are generally too weak to have a noticeable impact on Earth. M-class flares are stronger and capable of causing radio blackouts at high latitudes, while X-class flares are the strongest and can cause widespread radio blackouts, damage satellites, and knock out ground-based power grids, according to NASA.

M1 Geomagnetic Storm Warning Raised

Due to the flare on Saturday, the U.S. National Oceanic and Atmospheric Administration's (NOAA) Space Weather Prediction Center issued a minor M1 geomagnetic storm warning for Monday. This geomagnetic storm level o could have a slight impact on satellite operations, power grids, and animal migration patterns.

Meanwhile, skywatchers located in the Northern Hemisphere have treated to dazzling auroras thanks to the flare's coronal mass ejection (CME) interacting with Earth's atmosphere. The auroras were visible as far south as Scotland, Alberta, Canada, and the U.S. state of Montana, skywatchers posted on Twitter.

Most geomagnetic storms resulting from solar flares have minimal impact on Earth or spacecraft, although some powerful geomagnetic storms can impair electrical infrastructure or mess up radio communications. This year, the sun has been highly active, with large solar flares and coronal mass ejections disrupting satellite operations and creating brilliant auroras.

This increased activity could mean that the sun is starting to transition from a more restful phase of its cycle of activity in 11 years. Forecasters that the forthcoming solar cycle may be one of the strongest in history, although our forecasting abilities on the sun's behavior remain limited.