2023 is ending with a literal bang: an intense, powerful blast in the form of an X-class solar flare erupted from the sun today, making it the strongest such flare to occur since 2017. The flare peaked at 4:55 pm ET today.
An X5.0 flare (R3 Strong Radio Blackout) from NOAA/SWPC Region 3536. Today’s flare came from the same region that produced an X2.8 flare on December 14, 2023. It is also the largest flare to be observed since September 10, 2017 when an X8.2 flare occurred.
According to NOAA’s Space Weather Prediction Center (SWPC), a flare is an eruption of energy from the Sun that generally lasts minutes to hours.
“Flares of this magnitude are not frequent,” the SWPC said in an announcement today.
According to the SWPC, users of high frequency (HF) radio signals may experience temporary degradation or complete loss of signal on much of the sunlit side of the Earth.
Solar flares are giant explosions on the sun that send energy, light and high speed particles into space. These flares are often associated with solar magnetic storms known as coronal mass ejections (CMEs). Flares are ranked on a classification system that divides solar flares according to their strength. The smallest ones are A-class (near background levels), followed by B, C, M and X. Similar to the Richter scale for earthquakes, each letter represents a 10-fold increase in energy output. So an X is ten times an M and 100 times a C. Within each letter class there is a finer scale from 1 to 9. C-class and smaller flares are too weak to noticeably affect Earth. M-class flares can cause brief radio blackouts at the poles and minor radiation storms that might endanger astronauts. According to NASA, although X is the last letter, there are flares more than 10 times the power of an X1, so X-class flares can go higher than 9. NASA says the most powerful flare measured with modern methods was in 2003, during the last solar maximum, and it was so powerful that it overloaded the sensors measuring it. Those sensors cut out at X28.
As the flare exploded from the sun, it unleashed a tsunami of solar radiation that smashed into Earth and disrupted the planet’s magnetic field. This enabled the radiation to temporarily ionize the top part of Earth’s atmosphere, creating a massive albeit temporary radio blackout.
This is strongest solar flare of the current solar cycle. The sun’s activity is measured and forecast over 11 year cycles; activity this cycle is more intense than expected and the SWPC says more intense activity is likely to strike Earth in 2024.
Solar flares and coronal mass ejections can drastically impact Earth, with extreme events capable of destroying any unprotected electrical grid, electronics, and communications and navigation systems. In a severe event, it’s possible cars, boats, and aircraft would fail; radios, televisions, and phones would no longer work; modern conveniences like GPS navigation and the internet wouldn’t be able to work. Weaker events can also trigger beautiful nighttime aurora in the sky, illuminating areas free of obstructions and light pollution with dancing greens, purples, and reds.
If the SWPC determines yet another CME is headed towards Earth, they will issue Geomagnetic Storm Watches for it.
Coronal holes can develop at any time and location on the Sun, but are more common and persistent during the years around solar minimum. Coronal holes are most prevalent and stable at the solar north and south poles; but these polar holes can grow and expand to lower solar latitudes. It is also possible for coronal holes to develop in isolation from the polar holes; or for an extension of a polar hole to split off and become an isolated structure. Persistent coronal holes are long-lasting sources for high speed solar wind streams, also known as “CS HSS”. As the high speed stream interacts with the relatively slower ambient solar wind, a compression region forms, known as a co-rotating interaction region (CIR). According to the SWPC, from the perspective of a fixed observer in interplanetary space, the CIR will be seen to lead the CH HSS.
Strong CIRs and the faster CH HSS can impact Earth’s magnetosphere enough to cause periods of geomagnetic storming to the G1-G2 (Minor to Moderate) levels; although rarer cases of stronger storming may also occur.
While typically known for their weather forecasts, the National Oceanic and Atmospheric Administration (NOAA) and its National Weather Service (NWS) is also responsible for “space weather.” While there are private companies and other agencies that monitor and forecast space weather, the official source for alerts and warnings of the space environment is the Space Weather Prediction Center (SWPC). The SWPC is located in Boulder, Colorado and is a service center of the NWS, which is part of NOAA. The Space Weather Prediction Center is also one of nine National Centers for Environmental Prediction (NCEP) as they monitor current space weather activity 24/7, 365 days a year.
NOAA forecasters analyze a variety of solar data from spacecraft to determine what impacts a geomagnetic storm could produce. Analyzing data from the DSCOVER and ACE satellite is one way forecasters can tell when the enhanced solar wind from a coronal hole is about to arrive at Earth. A few things they look for in the data to determine when the enhanced solar wind is arriving at Earth:
• Solar wind speed increases
• Temperature increases
• Particle density decreases
• Interplanetary magnetic field (IMF) strength increases
While these solar events can help illuminate the sky with stunning aurora, they can also do considerable harm to electronics, electrical grids, and satellite and radio communications.
The 1859 incident, which occurred on September 1-2 in 1859, is also known as the “Carrington Event.” This event unfolded as powerful geomagnetic storm struck Earth during Solar Cycle 10. A CME hit the Earth and induced the largest geomagnetic storm on record. The storm was so intense it created extremely bright, vivid aurora throughout the planet: people in California thought the sun rose early, people in the northeastern U.S. could read a newspaper at night from the aurora’s bright light, and people as far south as Hawaii and south-central Mexico could see the aurora in the sky.
The event severely damaged the limited electrical and communication lines that existed at that time; telegraph systems around the world failed, with some telegraph operators reporting they received electric shocks.
A June 2013 study by Lloyd’s of London and Atmospheric and Environmental Research (AER) in the U.S. showed that if the Carrington event happened in modern times, damages in the U.S. could exceed $2.6 trillion, roughly 15% of the nation’s annual GDP.