'Space hurricane:' Why March is a wild month for space weather
A phenomenon called the Russell-McPherron effect gives us strange weather, all tied back to outer space.
We're barely a week into March and already there are reports of bright aurorae, coronal mass ejections, and an alleged "space hurricane."
It's hard to predict space weather, but scientists know that Earth's spring season coincides with increased solar activity — and it can affect our day-to-day life. What triggers these solar flareups, and why the month of March has such enhanced space weather conditions, is less obvious, however.
Inverse talked to space weather experts about how our host star causes geomagnetic storms with ramifications for life here on Earth.
Here's the background — The Sun fuels our very existence on Earth, but its behavior as a star can also be destructive. Periodically it sends out flares of boiling hot plasma into space, and Earth can get in the way. These flares are the culprit behind many space weather events.
The Sun is an active star, wracked by phenomena like coronal mass ejections, high-speed solar wind, and solar flares. Solar flares appear as bright areas on the Sun that cause a sudden flash — they're an intense burst of radiation, linked to magnetic energy associated with sunspots.
Coronal mass ejections are highly energetic eruptions from the Sun and the top source of major space weather events. They're composed of giant bubbles of gas and magnetic field released from the Sun. The ejections contain up to a billion tons of charged particles, and travel at high speeds which can reach several million miles per hour. The Sun periodically shoots out this boiling-hot plasma, flinging ionized material and radiation into outer space — and planets sometimes get in the way.
Carrie Black, program director at the National Science Foundation, studies ways to predict solar activity.
"Every time the Sun has these big eruptions, it's spewing out electromagnetic fields and particles," Black tells Inverse.
These ejections can cause magnetic storms in the Earth's upper atmosphere, which may affect power grids, satellites, orbiting spacecraft, and astronauts.
Robert Steenburgh, acting lead of the Space Weather Forecast Office at the National Oceanic and Atmospheric Administration, explains how the Sun's plasma eruptions reach our home planet.
"There are places on the Sun where the magnetic field lines are open, which allows high speed winds to escape into the heliosphere," Steenburgh tells Inverse.
"As the Sun rotates, approximately every 27 days on average, these coronal holes as they come around with the high-speed wind stream can impact Earth."
When these solar winds reach Earth, they can penetrate through Earth's protective layer of the atmosphere, known as the magnetosphere, and wreak havoc on our electric equipment and power grids.
"One of the reasons that the federal government has space weather as a priority is that a very large eruption could could impact Earth and potentially have big impacts to things like the power grid," Black says.
There are other ways solar wind can alter the pace of life on Earth, she says — although you might not have realized it was space weather.
"Airlines monitor the conditions of poles, because geomagnetic storms are dangerous for people to fly into often," Black says. "So if there's a big storm coming, they'll redirect all the flights."
What causes extreme space weather — The Russell-McPherron (R-M) effect accounts for variation in geomagnetic activity throughout the year. The hypothesis suggests the Earth experiences an enhanced level of geomagnetic activity during the spring and fall seasons.
Earth's changing seasons are due to our planet's tilted axis — the Earth tilts away from the Sun during winter and toward the Sun during summer. Earth's axis tilts by 23.5 degrees, but during the equinoxes — the beginning of the spring and fall seasons — the Earth is perpendicular to the Sun. During the spring equinox, which falls on March 20, the Earth is almost upright toward the Sun in that moment.
"That means that a particular coronal hole around the equinoxes, depending on the polarity, can have more of an effect in producing geomagnetic activity," Steenburgh says.
Earlier this month, a G2-class solar storm was reported by SpaceWeather.com, and beautiful, bright, haunting auroras were seen above Canada and Scotland.
Rest assured, these space weather conditions are not as extreme as they sound. A G2-class storm is actually pretty weak, and the effects experienced on Earth so far have been benign.
"Recently we had some minor storm conditions and briefly got up to moderate storm conditions, so that level of geomagnetic activity can trigger aurora in high latitudes," Steenburgh explains.
"And some people got some nice pictures of that."
Predicting solar storms
We can all enjoy the aesthetic effects of space weather, but NASA and NOAA are working hard to build better models to predict this phenomenon in case a more intense storm hit Earth in the future.
"There have been a lot of improvements, particularly from the startup of the study, but there's still a long ways to go," Black says. "Right now, it's difficult for the model to predict what the features on the surface of the Sun are going to be... the monitoring is dependent on what the Sun is doing immediately."
Space forecasting right now involves taking note of when something has erupted on the Sun and then using that information to predict when another eruption will likely take place.
"When features erupt on the surface of the Sun, then they go into models and predict which direction they're headed and when they might hit Earth, if they're going to hit Earth," Black says.
"But it's a vast space, there's 93 million miles and a lot of stuff can happen between the Sun and Earth."