Sun Unleashes Series of Huge Solar Flares Sending Storms Racing at Earth

A series of strong solar flares erupted from the sun on Saturday and Sunday, and the ejected material is set to cause a geomagnetic storm on October 4.

One of the flares was so strong that it may have caused a high-frequency radio communication blackout over a wide area for about an hour on Sunday afternoon, according to the National Oceanic and Atmospheric Administration's Space Weather Prediction Center (SWPC).

Data on the SWPC's website shows the three flares took place at roughly 4:15 p.m. ET on October 1, 10:25 p.m. ET on October 1, and 4:25 p.m. ET on October 2. In that order, they increased in strength from mid-M-class to X-class, the strongest type.

The powerful X-class flare can be seen on the upper right-hand side of the sun in the following image from NASA's Solar Dynamics Observatory (SDO).

Solar flares are bright flashes of radiation that burst out from the sun's atmosphere whenever the sun's twisted magnetic field lines suddenly shift. This magnetic rearrangement releases huge amounts of energy.

Sometimes a solar flare is the first part of a two-stage eruption. A flare consists of a flash of radiation that travels towards Earth at light speed, meaning its effects are felt as soon as we notice it.

Solar flares can cause disruption to high-frequency radio communication networks on Earth because these radio waves must bounce off a region of Earth's atmosphere known as the ionosphere in order to travel to their destination. Solar flare radiation ionizes the ionosphere, causing these waves to become degraded or completely absorbed.

"These types of disturbances affect the aviation and global navigation satellite systems communities in the civil dominant," George Ho, a space physicist at Johns Hopkins Applied Physics Laboratory, told Newsweek. "In addition, the military also relies heavily on high-frequency communication. It is reported that space weather disturbance may have caused communication blackout during Operation Anaconda."

Operation Anaconda was a March 2002 military operation in which CIA paramilitary officers entered Afghanistan to attack al-Qaeda and Taliban forces.

Mike Hapgood, a space weather scientist at the STFC Rutherford Appleton Laboratory in the U.K., said civil aviation will also be impacted by the high-frequency disruptions.

"The main industry affected by high-frequency radio blackouts is civil aviation—and specifically long-range communications to aircraft over oceans and remote land areas where there is no ground-based VHF radio network," Hapgood told Newsweek. "High-frequency is a primary method for aircraft in these areas to communicate with air traffic control. For example, flights over the North Atlantic will communicate with oceanic air traffic control centers provided by Canada, Iceland and U.K./Ireland.

"Many aircraft also have satcom as backup, but high-frequency is mandatory as part of international agreed procedures. So high-frequency blackouts can disrupt those links, but in general only for a few tens of minutes, so the industry can work round that disruption. These blackouts will not affect take-off and landing as aircraft will then use short-range VHF radio links."

The second part of the two-stage solar eruption is a coronal mass ejection (CME), which is a cloud of plasma and magnetic field that travels to Earth much more slowly than a flare does, generally taking multiple days. Solar flares do not always cause CMEs, but the two phenomena are associated with one another.

CMEs can interfere with Earth's magnetic field, causing effects such as increased drag on satellites, voltage issues in power grids, and auroras as well as communication issues.

On Sunday night, the SWPC issued a space weather notice on its website stating that a moderate-strength G2 geomagnetic storm was due to arrive on Tuesday, October 4. Potential impacts include some power grid fluctuations, high-frequency radio fading at higher latitudes, and auroras as low as New York to Wisconsin and Washington State.