A short time ago, a massive X flare exploded from the Sun, rated on the top of the charts in terms of intensity. According to the NOAA Space Weather Prediction Center (SWPC), at 6:57 pm Eastern Time, a massive X8.1 (R3) flare exploded from Region 4366 on the Sun. A solar flare is an eruption of energy measured in X-ray flux. According to the SWPC, flares of this magnitude in and around solar maximum are generally not common although not necessarily unusual.

The SWPC says that solar flares of this magnitude can be impulsive lasting some minutes or a few hours.

The immediate impact from this explosion are wider areas of strong degradation or signal loss in high frequency (HF) communication bands over much of the sunlit side of Earth; users of HF radio signals may experience loss of contact or major disruptions for a number of minutes to a couple of hours in impacted areas.

This same region produced an X 1.0 flare earlier today which is still very strong, but not nearly as strong as the flare that just occurred.

This latest  solar incident generated an R3 radio blackout, which is considered “strong” on a 5-point scale, where R1 is “minor” with weak or minor degradation of HF radio communications and navigation signals while 5 is “extreme” with a complete radio blackout on the entire sunlit side of the Earth lasting for a number of hours; such an event would also knock navigation systems off-line, which could lose to loss of positioning, especially by boats and planes.

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.

While today’s flare will lead to radio black-out issues, the SWPC says today’s blast from the Sun won’t harm humans. “While impressive, this event still poses no significant threat to the general public.”

While solar flares generally create a radio signal disturbance on Earth shortly after they happen, geomagnetic storm impacts usually lag behind by a few days.

Geomagnetic storms are rated on a 1-5 scale by the SWPC, with 1 considered minor and 5 considered extreme. Geomagnetic storms can disrupt electronics and electrical systems, interfere with spacecraft and satellite communication, and also trigger brilliant displays of the aurora in the night sky. It is not yet known what kind of geomagnetic storm will impact Earth as a result of today’s flares.

One frequent side effect of these geomagnetic storms is the presence of aurora. The probability and location of aurora displays is based on the Kp index of the storm. The K-index, and by extension the Planetary K-index, are used to characterize the magnitude of geomagnetic storms. The SWPC says that Kp is an excellent indicator of disturbances in the Earth’s magnetic field and is used by SWPC to decide whether geomagnetic alerts and warnings need to be issued for users who are affected by these disturbances. Beyond signifying how bad a geomagnetic storm’s impact can be felt, the Kp index can also help indicate how low, latitude-wise the aurora will be.

 

 

Coronal Mass Ejections (CMEs) are large expulsions of plasma and magnetic field from the Sun’s corona. They can eject billions of tons of coronal material and carry an embedded magnetic field, frozen in flux, that is stronger than the background solar wind interplanetary magnetic field (IMF) strength. CMEs travel outward from the Sun at various speeds, with some reaching the Earth as quickly as 15-18 hours and others requiring days to arrive. According to the SWPC, CMEs expand in size as they propagate away from the Sun and larger ones can reach a size comprising nearly a quarter of the space between Earth and the Sun by the time it reaches our planet.

As the CME interacts with Earth and its magnetosphere, a variety of things could unfold based on the amount of energy hitting and the angle it impacts the Earth. Power system voltage irregularities are possible and false alarms may be triggered on some protection devices.  Minor impacts on satellite operations could also be possible, with intermittent satellite navigation (GPS) problems likely.  Should the geomagnetic storm become stronger, aurora could be brighter and could appear even more south while impacts to electrical systems could be more severe.

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.

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.