Storms from the Sun: What Is Space Weather and Why Should We Care?
For Richard Carrington, September 1, 1859, began the same way that most of his days did. The amateur astronomer pointed his telescope at the Sun and began to make notes of his observations on the changing spots of the Sun’s surface. Unexpectedly, “two patches of intensely bright and white light broke out” according to Carrington’s quickly recorded observations. The lights were as bright as direct sunlight and only lasted for a few minutes before fading away.
That evening, the impacts of these flashes were felt around the world. The newly established telegraph system began experiencing mysterious outages as sparks traveled through the lines, shocking operators. The air was so electrically charged that messages could still be sent when telegraph equipment was unplugged. Dazzling aurora, better known as the Northern Lights and typically only visible in the upper Northern Hemisphere, could be seen as far south as Cuba and Jamaica. The sky was so bright that people and animals alike began to start their day, not realizing that it was still the middle of the night. In Boston, local newspapers reported people using the opportunity to read the paper, simply by the light in the night sky.
Although he did not realize it at the time, Carrington had witnessed one of the most powerful solar storms in recorded human history. The two white flashes that he spotted were solar flares that together released the energy of 10 billion atomic bombs. The event later was later given the name “The Carrington Event” and has become the quintessential example of the power that space weather can have on modern technological systems.
While the initial idea of space weather may conjure up images of intergalactic tornadoes and cosmic blizzards, space weather is a collection of phenomena that operate quite differently than terrestrial weather. Originating from the release of the Sun’s energy, space weather occurs when solar electromagnetic particles and radiation interact with the atmosphere and magnetic field of Earth. These interactions can have a wide range of impacts. While many solar storms miss Earth completely, some can have potentially catastrophic results, from wiping power grids to creating communication blackouts. As a result, it is imperative that scientists are able to understand how these events occur and accurately forecast when they will happen.
“In contrast to come other research disciplines, heliophysics has two components,” says David G. Sibeck, an astrophysicist at the Space Weather Laboratory at NASA Goddard Space Flight Center. “One is the one that gets the scientists really excited. It’s basic physics. We’re going to learn how something works and we’re going to understand the fundamentals. But in contrast to some other disciplines, we have a very practical side, the space weather side. The phenomena that we study are hazardous to human endeavors, hazardous to astronauts, hazardous to spacecraft and hazardous to communications. Those are all topics that merit understanding how the phenomenon works, how severe the phenomenon is and learning how to predict when it occurs, so that we can take measures to protect ourselves. Space weather is worth studying because it can improve life in our society.”
Similar to the way that the Earth experiences seasons, the Sun also goes through patterns of activity that are known as the solar cycle. Yet unlike seasons, each solar cycle is roughly 11 years in length. The cycle begins with the solar minimum, where there is little action happening on the Sun and violent solar storms are rare. As the cycle continues, solar activity increases until it reaches solar maximum at the midpoint of the cycle. After reaching the zenith of solar activity, action once again decreases back to a solar minimum and the cycle repeats. This year, scientists officially announced that the Sun has entered into its 25th solar cycle, which means that it is in a period of solar minimum and will slowly begin working its way toward solar maximum.
Space weather occurs as a result of the Sun’s dynamic surface. Unlike the Earth, the Sun is an explosive, high-energy environment. It is constantly emitting energy in the form of charged particles and electromagnetic radiation. These charged particles travel away from the Sun at incredibly high speeds into the rest of the solar system, where they interact with other astronomical objects, from orbiting satellites to the Earth itself.
As the Sun continuously creates its own energy through burning hydrogen, it releases those particles of energy into the solar system in the form of solar wind. Traveling away from the Sun in a state of matter known as plasma, the solar wind is so hot that the atoms of which it is composed are split into electrons and ions, which are atoms missing electrons. This means that the solar wind has an electric charge and is strongly influenced by electromagnetic fields and forces. At the equatorial plane of the Sun, which is the plane around the Sun where the Earth and other planets in the solar system orbit, the wind comes off relatively slowly. However, for the Sun, “slow” is a measly 400 kilometers per second, or for Americans, 894,775 miles per hour. That would get you quite the speeding ticket on any highway. When evaluating the impact of the solar wind on Earth, speed is important to monitor because while these “slow” speeds create the calm space weather effects that most people are familiar with, such as the aurora, higher wind speeds can lead to major space weather disturbances, such as geomagnetic storms. As a result, it is critical for space weather forecasters to understand and monitor the changes in the solar wind to accurately prepare for its impacts.
“The plasma, or the gas at the Sun, is constantly being boiled off and forming solar wind,” Sibeck says. “There’s never a time when nothing is happening. The solar wind never disappears and as the Sun rotates, you get streamers or strings of magnetic fields that come out like a pinwheel from it. The plasma carries the magnetic field out into interplanetary space, past the earth. Our poor Earth’s magnetic field is standing in the way, so it’s constantly getting battered by blobs of plasma from the Sun and solar wind.”
While the Sun is continuously emitting the solar wind, that is not the only thing it likes to send out into the solar system. During periods of high solar activity, eruptions can occur on the Sun known as solar flares. Solar flares release sudden outbursts of electromagnetic energy, which is energy that travels in waves and carries an electromagnetic field. The window for a solar flare can last from a few minutes to a few hours. However, their impacts can be felt on the Sun-facing side of Earth, almost immediately since electromagnetic energy travels at the speed of light.
The biggest problem that solar flares can cause does not actually happen on the ground, but in the ionosphere. In the ionosphere, which is a layer of Earth’s atmosphere, radiation from the Sun gives the atoms and molecules an electric charge and creates a layer of electrons. Under normal conditions, these electrons make modern communications possible by bouncing and refracting the high frequency radio waves that are used for communicating. However, when a solar flare occurs, it sends increased levels of x-rays and extreme ultraviolet radiation creates more ionization lower in the atmosphere. This extra energy can cause some of the high frequency radio signals. In severe situations, this can lead to a radio blackout, such as during the 2017 hurricane season. Yet while solar flares are no minor event, they are mild compared to their cousins, coronal mass ejections.
Coronal mass ejections (CMEs) are large explosions from the outer atmosphere of the Sun, called the corona. While they can occur at the same time, CMEs differ from solar flares in the types of particles ejected, the way they travel and the impacts that they can have on Earth. Solar flares predominately release energy in the form of electromagnetic radiation, but CMEs hurl billions of tons of magnetized particles into space like a cannonball being fired. They do not travel as fast as solar flares, but the magnetized particles do race away from the Sun at speeds of more than a million miles per hour in the form of plasma. If a CME is on a trajectory to hit the Earth, it will do so typically within three days; however, the fastest ones are able to reach the planet in 15 to 18 hours, giving forecasters little time to prepare for the potential damage.
“These coronal mass ejections carry in them a magnetic field,” said Robert Steenburgh, a former meteorologist and current space scientist with the Space Weather Prediction Center at the National Oceanic and Atmospheric Administration. “When that magnetic field gets to Earth, it will interact with Earth’s magnetic field. It’s just like playing with refrigerator magnets. If you orient the poles correctly, it will stick together. If you don’t, then they’ll repel. If the CME is [magnetically] oriented in such a way that it sticks to Earth, then that has the potential to make a larger geomagnetic storm.”
When space weather events interact with the Earth, they carry energy and the Sun’s magnetic field with them. Like repelling magnets, disturbances in the Earth’s atmosphere occur when the magnetic field coming from the Sun has an opposing magnetic orientation to that of the Earth. The exchange of energy from the event, whether it be the solar wind, a solar flare or a CME, produces changes, electric currents and plasma in the Earth’s magnetosphere as well as potentially large magnetic disturbances on the ground. These currents can create errors in GPS and navigation systems as well as disable radio communications by modifying radio signals. On the ground, the magnetic disturbances can trigger harmful geomagnetically induced currents (GICs) that can destroy power grids and pipelines. Thus, the impacts of space weather can be disastrous, especially when preventative measures are not taken to mitigate risks.
In September 2017, as Category 5 Hurricanes Irma wreaked havoc on the Caribbean region alongside Hurricanes Katia and Jose, a different type of storm brewed 93 million miles away. There, an active solar region known as AR12673 prepared to erupt in a violent series of solar flares, solar energetic particles and coronal mass ejections, all pointed directly at Earth. Upon reaching the Earth’s atmosphere, the flares induced a near-total radio blackout as responders in the Caribbean were quickly trying to bring aid to the hurricane-stricken regions. Even with safeguards in place for such an event, the blackout lasted nearly three hours and undoubtedly exaggerated the already devasting effects of the hurricanes on these areas. While there are no discovered ties between extreme space weather and extreme Earth weather, it is a cruel twist of fate to have the worst solar flare of the decade coincide with such a calamitous hurricane season.
“The problem was that the flares were wiping out the ability to communicate with the islands when the islands really needed to be able to communicate,” Steenburgh says. “Even more remarkably, I found out from a colleague who works in Mexico and leads the Mexican Space Weather Center that they had, simultaneously, the largest earthquake in Mexico since 1932, coupled with a hurricane coming on shore in Mexico and the space weather events. That was a very busy day for him having to deal with the civil authorities and all the rumors because with the advent of social media, stuff spreads like wildfire and it doesn’t take much for something to grab hold.”
Decreased ability to communicate during emergency responses is just one of many negative impacts that space weather can have on Earth. Traditionally, the industries that are most susceptible to space weather interference are aviation, communications and power grids. However, even activities as unexpected as pigeon racing witness the influence of space weather. For example, pigeon racers release racing homing pigeons who then travel hundreds of miles back to their home. The pigeons navigate this journey by sensing the magnetic field, but major solar activity distorts that magnetic field and can cause the pigeons to get lost. With champion racing pigeons prices rivaling a new Ferrari, pigeon racers meticulously pay attention to space weather conditions when choosing whether to fly.
For the aviation community, the hazards of space weather influence their jobs on a regular basis. During increased solar activity, navigation and communication abilities can be lost, leaving pilots uninformed of their whereabouts and unable to communicate with dispatchers. Flights routed over the poles, which have become increasingly popular in recent years, face more risk as both space and ground-based communication systems are less reliable at higher latitudes. Another harm comes from the actual radiation that accompanies space weather. Normally, the Earth’s magnetosphere shelters the planet from the barrage of charged particles that the Sun sends toward us. Unfortunately, those protections are weakened at high altitudes, exposing people on planes to higher levels of radiation than they would be on the ground. For the average flier, these levels are not high enough to cause any concern or negative impacts. However, for pilots and crew members that spend prolonged periods of time in the air, they must routinely monitor their radiation levels. Thus, even during relatively calm periods of solar activity, the charged particles carried by the solar wind ensure that space weather is a concern for the aviation community.
Modern communication relies predominately on satellites transmitting radio signals to each other, which does everything from allowing communication during natural disasters to bringing a YouTube video of a sneezing panda to your phone. Likewise, satellites provide GPS capabilities to Earth for applications such as agriculture and construction alongside the traditional usage for navigation. Space weather activity interrupts the transmission of information by distorting the paths of the radio signals and rendering the satellites incapable of relaying accurate information to their intended outputs. In extreme solar events, satellites can lose communication entirely, which leads to radio blackouts such as those experienced during Hurricane Irma.
Perhaps the industry that faces the most substantial threats from space weather is the power industry, whose relationship with space weather traces back decades. When solar activity triggers geomagnetic storms, the resulting influx of electric currents that travels through the ground has the potential to oversaturate power lines and transformers. Overloaded systems can experience structural damage that could lead to partial or system-wide blackouts on the scales of cities or larger. Even once the lights come back on, replacing damaged parts, such as transformers that convert alternating currents to different voltages, can be costly and timely since they are specially made and large quantities of spare parts do not exist. If a particularly severe solar storm, such as a series of CMEs, were to strike the Earth, it could leave an entire coastline of the United States without power and cause lasting and irreparable consequences.
The quintessential example of space weather’s influence on power grids comes from a 1989 solar storm that crashed into the Earth and sent electrical currents running beneath the ground in North America. These currents unfortunately found a weak spot in Quebec’s electric power grid and within minutes, they triggered a blackout that would last almost 12 hours and span the entire province. The United States did not experience blackouts, but many electric companies struggled to manage the repercussions of the storm. Although a dramatic example, the Quebec blackout illustrates the widespread chaos that space weather can ensue, especially when those operating the power grids are underprepared.
“A lot of people don’t know that space weather can cause problems,” said Yarieska Collada-Vega, a research astrophysicist at the Community Coordinated Modeling Center with NASA Goddard Space Flight Center. “For example, communications, GPS, power grids, there are many things that could happen just because of the Sun’s activity and a lot of people don’t understand that. Your cell phone can have problems. That technology that we use every day can be damaged because of space weather. Not only that, we want to explore or want to send astronauts to space, but that means that to do that, basically, we have to be able to forecast space weather and have the models prepared to do that.”
While any of these industries individually may not appear to warrant the catastrophic potential that space weather possesses, the reality is that space weather is what is known as a “low-frequency, high-risk” event. This label can also be applied to natural disasters or any other event that may not occur often but can cause severe damage when they do. If a Carrington-level solar storm happened today, scientists estimate that it could take trillions of dollars and years to recover. In fact, Earth came extremely close to experiencing a Carrington-level solar storm in 2012 when an active region of the Sun launched multiple CMEs into space. By one measurement, the storm was almost twice as strong as the worst geomagnetic storm of the Space Age that caused the 1989 blackouts in Quebec. Thankfully, the location of the Earth in its orbit placed it in a position where it was safely out of the way of the CME. An article published by a team of NASA scientists in the December 2013 issue of the Space Weather journal suggested that if the storm had occurred only a week earlier, it is highly likely that its impacts would have still been felt years later.
Ultimately, the ability to properly mitigate the risks that accompany space weather is contingent on the ability to properly forecast solar activity and subsequent space weather events. With weather on Earth, meteorologists are able to identify patterns and signs in data in order to make weather predictions. Unfortunately, space weather scientists have access to only a fraction of the amount of data that meteorologists have, so they rely heavily on physical and mathematical modeling to predict when space weather events might occur.
The Community Coordinated Modeling Center (CCMC), located at NASA Goddard Space Flight Center, is one such group working to better understand and predict space weather events. By assembling, validating and testing various space weather models, the team at the CCMC bridges the gap between space weather research and operational decisions made by groups susceptible to impact by space weather events. Researchers can submit models to the CCMC, who has access to the databases, computer power and scientific and technical personnel necessary to properly run and assess the accuracy of the models by comparing it to physical results. These models cover the entire lifespan of space weather, from the solar corona to the Earth’s magnetosphere. When attempting to predict space weather phenomena, the ability to utilize models plays an integral role in the forecasting process. Respectively, it is imperative for the models used in forecasting and other operational applications to be as valid as possible because inaccuracy can result in potential unpreparedness in a space weather event. Additionally, although the CCMC resides at a NASA center, it illustrates the multi-disciplinary threats that space weather can pose through their partnerships with the Air Force, National Science Foundation, NOAA and Office of Naval Research.
“We need the data,” says Collado-Vega. “That’s first and foremost, very important. We need a data set. We need to be able to have the capability to measure this activity and then we need to validate the model so we can have some kind of prediction or forecast of what is going to happen later on and actually have a warning time. Our job here is really, really important because we not only support the development of space weather research, but also support the development of the transition of those models from the development part to operation.”
While the CCMC focuses on running and validating models, the NOAA Space Weather Prediction Center (SWPC) concentrates on using those models and data to provide their user community with the necessary precautions during a space weather event. In other words, the SWPC translates forecasts and data openly on their website to make it meaningful information for interested parties and individuals. Similar to the way hurricane forecasting on Earth, the team at the SWPC can determine if a space weather event is likely to develop and track that storm as it races away from the Sun. Before it reaches the Earth, the storm would hit NOAA spacecraft that are continuously monitoring the space environment and informs the scientists of potential storms. Using a series of scales that parallel those used to describe the intensity of Earth storms such as hurricanes and tornadoes, NOAA notifies its customers with alerts, warnings and watches of the impeding storm so that they can engage in preventative measures, such as closely watching the power grid for potential issues and readjusting the system to mitigate those risks. Incredibly, the average citizen goes about their day entirely unaware that any of this is happening.
“One of the things forecasters have to do, whether they’re meteorologists or space weather forecasters, is make big, impactful decisions with very limited data,” says Steenburgh. “It’s even more challenging to some degree as a space weather forecaster because you have less data and you have interruptions to many of our sources of data. There’s no guarantee that our research instruments will always be available, so we can lose data. My analogy is you have one Earth-observing weather station in Tokyo and you’re supposed to make a one week forecast for Baltimore, Maryland using only that data.”
Models and forecasts are important, but scientists cannot make these precdicitons without the necessary data from the Sun. New questions about space weather continue to arise and space agencies such as NASA and the European Space Agency (ESA) recognize the importance of studying the Sun as closely as possible. In August 2018, NASA launched the Parker Solar Probe, which has championed records for fastest manmade object and traveled closer to the Sun than any other spacecraft. Only a few years into its mission, Parker Solar Probe has already provided scientists with new insights into the physics and causes of solar wind, among other important data. Additionally, NASA and ESA launched the Solar Orbiter in February 2020 which will capture the first glimpses of the Sun’s poles, an uncharted territory for heliophysics. Solar Orbiter will also track the regions of the Sun that could possibly lead to CMEs and supply scientists with more data to make their forecasts.
“Parker is primarily a fundamental basic science mission,” said Adam Szabo, mission scientist for Parker Solar Probe at NASA Goddard Space Flight Center. “It’s not designed to be a space weather monitor, but whatever it discovers has implications on our future space weather prediction capabilities.”
Ultimately, while many questions still remain about the detailed physics and origins of space weather, there has also never been a time where scientists know so much information about these phenomena. At least one picture of the Sun has been captured every second for the past ten years. With a society that becomes more technology-dependent each day, the importance of understanding and properly forecasting space weather increases as well. Embracing the feelings of curiosity and excitement that accompanied early space age research, the age of space weather has arrived as scientists eagerly attempt to unlock the mysteries of our neighborhood star.
“I think this is a golden era to be in space weather, space physics or heliophysics,” says Sibeck. “We need more spacecraft, but we’ve never had this many before. There are all kinds of studies. We’re learning so much all the time. Of course, we’d like to do more, but nevertheless, this is a wonderful time to be in our field.”
