Solar flare disrupts shortwave radio

SEOUL, July 7 (UPI) -- A solar flare disrupted shortwave radio transmissions for half an hour in South Korea, the country's National Radio Research Agency says.

The agency issued an alert just after 8 a.m. Friday, Yonhap News Agency reported.

Solar flares, a temporary local increase in brightness, release large amounts of energy that increases the ionization of Earth's upper atmosphere. That disrupts shortwave, high-frequency transmissions and can also affect satellites and cause problems for astronauts.

The U.S. Space Weather Prediction Center said the flare was the brightest so far this summer, Space.com reported.