Solar flares caused radio blackouts that disrupted hurricane relief efforts in September 2017, when three separate Atlantic Ocean storms posed a threat to land, according to a new study published in the American Geophysical Union’s (AGU) journal Space Weather.
As category 5 Hurricane Irma made landfall in Barbuda, Tropical Storm Katia intensified in the Gulf of Mexico, and Tropical Storm Jose headed toward the open ocean on September 6, two major solar flares erupted on the Sun’s surface.
Both tropical storms were upgraded to hurricanes later that day. Both solar storms were of the most intense X-class, with the first an X-2.2 and the second an X-9.3.
As warned by the National Oceanic and Atmospheric Administration’s (NOAA) Space Weather Prediction Center, radio communications went down for several hours during the morning and afternoon, as reported by amateur radio operators helping with emergency communications to the islands affected by Hurricane Irma.
Several days later, NOAA confirmed that high-frequency radio, used by emergency bands, did not operate for as long as eight hours on September 6.
Another X-class flare that erupted on the Sun on September 10 took radio communication down for three hours, just as Hurricane Jose battered the Bahamas and Leeward Islands, and Hurricane Irma bore down on Cuba.
A group of licensed amateur radio operators known as the Hurricane Watch Net confirmed the solar flares disrupted radio communications over several critical hours.
“You can hear a solar flare on the air as it’s taking place,” said Hurricane Watch Net manager Bobby Graves of Jackson, Mississippi. “It’s like hearing bacon fry in a pan; it just all of a sudden gets real staticky and then it’s like someone just turns the light completely off, you don’t hear anything. And that’s what happened this last year on two occasions. We had to wait ’til the power of those solar flares weakened, so that our signals could actually bounce back off the atmosphere. It was a helpless situation.”
The coinciding of both space and Earth weather aggravated an already tense situation, confirmed study lead author Rob Redmon, space scientist with NOAA’s National Centers for Environmental Information (NCEI) in Boulder, Colorado.
During hurricanes and tropical storms, amateur radio operators transmit crucial information regarding people who need rescue.
The study provides suggestions on improving the prediction of space weather and discusses safeguards that can be put in place to better deal with a joint recurrence of Earth and space weather. It also acknowledges that some protections that already were in place did alleviate the situation.
“Safeguards put in place to prevent dangerous disruption to GPS from solar events worked. In many ways, we were ready. Some things that could have caused big problems didn’t, but shortwave radio is always tricky to use during solar events. But good radio operators are aware of the events and will work hard to overcome problems,” stated Mike Hapgood, head of space weather at Rutherford Appleton Laboratory in the United Kingdom.