Powerful M9.5 solar flare causes radio blackout in Pacific Ocean

A new powerful solar flare has occurred, causing massive radio communications blackouts throughout the Pacific region. The peak of the outbreak occurred on April 30 at 23:46 GMT and ended after 12 minutes.

During solar flares, intense bursts of electromagnetic radiation occur. Experts distinguish several types of outbreaks, depending on their intensity. X-class flashes are considered the most powerful. Then there are M-class flares, which are 10 times less powerful than X-class flares, then C-class flares, which are 10 times weaker than M-class flares. In turn, B-class flares are 10 times weaker than C-class flares and, finally, M-class flares are 10 times weaker than C-class flares. There are also class A flares, but they have no effect on Earth.

Within each class, numbers from 1 to 10 (and higher for X-class flares) describe the relative strength of the flare. According to Spaceweatherlive.com, the recent flare, which occurred on April 30, was estimated to be M9.53, only slightly weaker than an X-class flare.

According to Space.com, shortwave radio blackouts, such as those observed over the Pacific Ocean, are considered common shortly after powerful solar flares due to for the intense pulse of X-rays and extreme ultraviolet radiation emitted during the event. The radiation “flies” towards the Earth at the speed of light and ionizes the upper part of the Earth’s atmosphere.

This ionization creates a higher-density environment, and high-frequency short-wave radio signals must pass through it to maintain communications over long distances. However, radio waves that interact with electrons in the ionized layers lose energy, and this can lead to deterioration or complete absorption of radio signals.

Radiation from the solar flare on April 30 affected those parts of the Earth on which sunlight fell at that moment - the Pacific regions. According to Spaceweather.com, for as long as 30 minutes after the peak of the flare, sailors and radio amateurs could notice a loss of signal at frequencies below 20 MHz.