Severe (4 out of 5) Geomagnetic Storm Watch in Effect; Aurora Likely

A series of explosions have ejected mass and energy off the surface of the Sun in the last few days; some of that energy could interact with the earth's magnetosphere and create a geomagnetic storm. (Image Not To Scale) Image: SWPC — A series of explosions have ejected mass and energy off the surface of the Sun in the last few days; some of that energy could interact with the earth’s magnetosphere and create a geomagnetic storm. (Image Not To Scale) Image: SWPC

A Geomagnetic Storm Watch has been issued by NOAA’s Space Weather Prediction Center (SWPC) as a Severe Geomagnetic Storm rated G4 on a scale of 1-5, where 5 is the most severe, is predicted to blast Earth this weekend. Multiple coronal mass ejections (CME) from the Sun are expected to merge and impact Earth sometime late May 10 or May 11. “Watches oat this level are very rare,” the SWPC warned in an update issued today. The geomagnetic storm create many impacts and effects around the globe including igniting a brilliant display of aurora, or “Northern Lights”, in areas that don’t usually see them.

“The aurora may become visible over much of the northern half of the country, and maybe as far south as Alabama to northern California,” the Space Weather Prediction Center said in an update today.

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. When the impacts arrive on Earth, a geomagnetic storm occurs.

This Severe Geomagnetic Storm Watch is the first to be issued since 2005. Image: SWPC

“Infrastructure operators have been notified to take action to mitigate any possible impacts,” the SWPC previously said. “Possible increased and more frequent voltage control problems – normally mitigable. Increased possibility of anomalies or effects to satellite operations. More frequent and longer periods of GPS degradation possible,” they add.

Multiple CMEs erupted from flare activity on the Sun in an area known as “Region 3664” on May 7, 8, and 9.

This map shows how far south the Northern Lights could appear at different KP index levels. While a KP of 3 or less would keep them in northern latitudes of Alaska and Canada, a KP of 9 would make them visible in places like Salt Lake City, St. Louis, Washington, DC, Chicago, Philadelphia, New York, Boston, and Portland. Image: NOAA

The SPWC is calling for a “severe” storm to impact Earth; a Kp index of 8 or greater is possible.

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.

Computer rendering of aurora, also known as "Northern Lights", over an American city. Image: Stable Diffusion AI — Computer rendering of aurora, also known as “Northern Lights”, over an American city. Image: Stable Diffusion AI

The greater the Kp index number, the more vibrant aurora can be; in the Northern Hemisphere, a higher Kp index also means the aurora could establish itself high above the United States in southern locations that don’t ordinarily see the Northern Lights. Should the Kp index be less and around 4, aurora would only be visible in places like northern Michigan or Maine areas. A KP index of 7 or more could make the aurora present in clear skies in Boston, Chicago, and Seattle; a Kp index of 9 or more could illuminate the clear night skies of Washington, DC, Saint Louis, Denver, and even Salt Lake City. In past severe geomagnetic storms, the aurora has been visible as far south as Hawaii and the central Caribbean.

To view the aurora, you must be in an area free of obstructions, like clouds, and free of light pollution, such as street lights or city lights. They can be seen anytime in the dark by looking up or up towards the north sky. Depending on the intensity of the event and your location, they may appear as a floating ribbon of color, a brief flicker of greens, purples, or reds, or both. They may be visible briefly, intermittently, or over many hours.

Chart showing NOAA Space Weather Scales for Geomagnetic Storms. Image: NOAA

While a higher Kp Index generally produces a more spectacular aurora display, it also presents more of a danger to systems that could be impacted by geomagnetic disturbances. Electrical system failures, grid failures, communication and navigation system faults, and more could happen if the geomagnetic storm is powerful enough.

For now, the SWPC says this strong geomagnetic storm will create a variety of problems with electrical, communications, and navigation systems. Voltage corrections may be required on some power systems while false alarms may be triggered by some protection devices. Intermittent satellite navigation and low-frequency radio navigation problems can also occur.

Above Earth, this geomagnetic storm can also damage satellites and spacecraft. These impacts can also effect astronauts on the International Space Station; in previous storms, astronauts were encouraged to go to more protected parts of the space station, according to NASA.

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 Sun is constantly churning material and magnetic fields which create an ever-changing landscape of features that last from milliseconds to days. NASA developed this infographic to illustrate a few of the most common features that can be seen on the Sun. Image: NASA/Mary Pat Hrybyk-Keith — The Sun is constantly churning material and magnetic fields which create an ever-changing landscape of features that last from milliseconds to days. NASA developed this infographic to illustrate a few of the most common features that can be seen on the Sun.
Image: NASA/Mary Pat Hrybyk-Keith

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.