Korean Air and Asiana Airlines are taking precautions to deal with the potential impact on their communications equipment of a solar storm after the largest one in at least six years flared up on Monday in the northern hemisphere.

Korean Air’s incoming flights from Canada and the U.S. have been rerouted away from the North Pole to avoid rays from the solar storm, lengthening traveling times by at least 40 minutes. Asiana has also temporarily changed its Korea-bound routes coming in from New York and Chicago.

Solar storms, also called proton storms, are not directly harmful to humans, but they can play havoc with aircrafts’ instrument panels, especially their radio communications and GPS navigation systems as the large flares also interfere with the operations of satellites.

The storms are created by huge solar bursts that pound the Earth with radiation, which can lead to spectacular light shows at times. Scientists predict that next year will see the phenomenon hit its zenith.

Foreign airlines such as Delta and United Airlines, which also use the polar region routes, have changed their flight paths as well.