by Ryu Hyunseok
Published 11 May.2024 19:16(KST)
The most powerful solar storm in about 21 years has struck the Earth.
The Space Weather Prediction Center (SWPC) of the U.S. National Oceanic and Atmospheric Administration (NOAA) announced on the 10th (local time) that an extreme-level G5 geomagnetic storm has reached the Earth.
Geomagnetic storm levels are classified into five stages from G1 to G5, with G5 being the most intense.
Earlier, SWPC issued a G4 warning for the first time in about 20 years. However, the geomagnetic storm intensified to G5 level at 6:54 PM Eastern Time on the same day.
This is the first time since October 2003 that a G5-level geomagnetic storm has hit the Earth. At that time, the geomagnetic storm caused power outages in Sweden and transformer damage in South Africa.
According to foreign media, this geomagnetic storm showed varying intensities ranging from moderate to severe levels.
Space weather forecasters at SWPC observed at least seven coronal mass ejections (CME) from the sun. The effects are expected to continue until the 12th of this month.
When coronal material reaches the Earth, it generally affects the Earth's magnetic field, causing radio interference and satellite operation disruptions.
According to NOAA, a G5-level geomagnetic storm can cause widespread voltage control problems on Earth. Some power grids may completely collapse or experience blackouts.
It can also cause issues with spacecraft and satellite operations. High-frequency radio waves may be unavailable in many areas for 1 to 2 days. Satellite navigation performance may degrade for several days, and low-frequency radio navigation may be interrupted for several hours.
NOAA explained, "Plasma and magnetic fields erupting from the sun's corona head toward Earth, causing geomagnetic storms. This affects infrastructure in low Earth orbit and on the Earth's surface, potentially disrupting communications, power grids, navigation, radio, and satellite operations."
Foreign media explained that mobile phone communications used by general consumers operate on radio frequencies different from high-frequency bands, so they are not directly affected by this geomagnetic storm.
As a result of this geomagnetic storm, auroras were observed across northern Europe, the southern and central United States, and other regions.
Auroras were visible in France, Spain, Italy, Austria, southern Switzerland, and London in the United Kingdom. In the U.S., aurora sightings were reported in central Virginia, Colorado, Kentucky, North Carolina, New Mexico, Mississippi, Florida, and Texas. In the Southern Hemisphere, auroras were observed in Chile, Argentina, New Zealand, and India.
Auroras occur when part of the solar wind enters the Earth's magnetic field and collides with the atmosphere, emitting light. They mainly appear in high-latitude regions such as the Arctic Circle. Explosions on the sun's surface are known to occur during the process of magnetic fields in sunspots reconnecting.
The largest geomagnetic storm in history is known as the "Carrington Event" of September 1859. At that time, telegraph networks in North America and Europe were disrupted, and fires broke out, causing significant damage.
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