X1.27 Solar Flare: Strongest Eruption in Years Disrupts Radio Communications

Recently, the sun surprised observers with a powerful X-class solar flare originating from sunspot AR3738. NASA’s Solar Dynamics Observatory captured this intense event at 10:34 p.m. EDT on July 13 (0234 UT on July 14). Despite its dramatic display, the flare did not generate a coronal mass ejection (CME) — a massive release of plasma and magnetic fields from the sun.

Solar physicist Keith Strong, monitoring the situation closely, indicated that no CMEs resulted from the recent eruptions. Consequently, he expects minimal geomagnetic activity due to this heightened solar activity.

Following the X-class solar flare, widespread shortwave radio blackouts affected regions including Australia, Southeast Asia, and Japan. These interruptions are typical after such powerful solar events, caused by intense emissions of X-rays and extreme ultraviolet radiation from the flare. Radiation from solar flares travels to Earth at the speed of light, ionizing the upper atmosphere upon arrival.

This ionization increases the density of the ionosphere, enabling high-frequency shortwave radio signals to travel over long distances. However, as radio waves interact with electrons in these ionized layers, they undergo more collisions, resulting in energy loss that can degrade or absorb the radio signals entirely.

The recent solar flare on July 14 registered as an X1.27 event according to Space Weather Live. Solar flares are explosive releases of electromagnetic radiation from the sun’s surface, triggered by the sudden release of magnetic energy stored in the solar atmosphere. They are classified based on their strength, with X-class flares being the most intense, followed by M-class, C-class, B-class, and A-class flares, each progressively weaker.