On Oct. 31, 2021, the northern lights were visible over a village close to the Russian Arctic.
The sun is rising and is making sure that we all know it.
Earth was struck by a large geomagnetic storm on Wednesday and Thursday, Nov. 3 and 4. This was the result of several outbursts from its sun on Monday and Tuesday (Nov. 1, 1 and 2). These outbursts can be attributed to sunspots. Sunspots are magnetic storms that occur on the surface of the sun. Sunspots and solar activities are both part of a cycle that lasts about 11 years. This week's storms reflect the current stage of that cycle.
"The last few years have been very quiet, as is typical during solar minimum. But now, we're ramping up and speeding up quite quickly into the next solar cycles maximum," Bill Murtagh (a program coordinator at NASA's Space Weather Prediction Center) told Space.com.
Similar: This NASA video captures the sun's massive solar flares.
Murtagh stated, "We are seeing the increase of activity that one would expect from this rise in solar cycle." This is a sign of our awakening phase.
As this week's storms showed, solar activity can affect more than the sun. Solar outbursts can also cause space weather, which can have a range of effects from satellite damage to beautiful auroral displays.
Storm from a CME 'cannibalized'
This week's geomagnetic tornado was caused by a series coronal mass ejections (or CMEs), which are bubbles made of solar material that sometimes burp out. Murtagh explained that a CME is basically a billion-ton cloud plasma gas with magnetic field. "So the sun sent a magnet into space, and that magnet made the 93 million-mile transit from Earth to the sun." That's 150,000,000 kilometers.
However, Earth's magnetic field is unique and can mix with other magnetic fields in space. Murtagh stated that the CME will cause "the two magnets to come together" and create a geomagnetic storm.
Sometimes, a CME may grow as it moves across space. The geomagnetic storm of this week was the result of a series combining outbursts. A later CME moved faster that its predecessor. Murtagh stated that the first CME basically works its way through the 93,000,000 miles, almost clearing a way for other CMEs. "Sometimes, we use the term "cannibalizing" the one ahead.
The strength of such a storm depends on the size of both the CME as well as the alignment of the magnetic fields. No matter what, a large enough CME and a geomagnetic storm can cause severe damage. The picture is complicated for CMEs of medium size, such as the one that struck this week.
Insert "This is part of our awakening phase." Here is Bill Murtagh (SWPC program coordinator).
Murtagh and his coworkers can model the path of a CME from the sun across space. However, they don't learn the magnetic field of a CME until it reaches a NOAA spacecraft called Deep Space Climate Observatory ( DSCOVR). This spacecraft hovers 1.5 million kilometers (a million miles) away from Earth.
Murtagh stated that the big, major events are the easiest. "Events such as the one we had over the past few days are excellent examples of not-easy ones, because they're not powerful CMEs of extreme magnitude. They are quite strong but we don’t know the magnetic structure of that CME until it hits DSCOVR spacecraft.
The CME will strike Earth in 20-30 minutes. This means that the geomagnetic storm could be imminent.
A coronal mass eruption exploded off the sun on Nov. 2, 2021. Image credit: SOHO NASA & ESA.
Earth's space weather
Geomagnetic storms can be more than an interesting phenomenon. These events can cause disruptions to critical infrastructure such as power grids, navigation satellites, and radio communications between aircraft in remote areas. The Space Weather Prediction Center was created to monitor the space weather and alert infrastructure operators when trouble is likely.
Murtagh said that the center automatically notifies power grid operators in Canada and the U.S. about a storm such as this week's. However, there is a low chance of it going terribly wrong. Murtagh stated that they want to know when it is happening so that they are prepared.
He stated that the office had received reports of impacts consistent with what was expected for a storm this size.
Murtagh stated that this kind of storming has been experienced in hundreds of cases, giving us a good idea of what it will do to our grid. "They are seeing it, they feel it, and we're starting to see some voltage irregularities, but it's manageable at this level.
This may not always be true. The impacts can be even more severe if the "cannibal CME” phenomenon occurs with larger outbursts.
"We have determined that this is the worst-case scenario of an extreme geomagnetic thunderstorm event." Murtagh stated. "It was just that the CMEs weren't that large, but that process took place here, when we had back-toback two, three different CMEs come sweeping in together."
Artist's rendering of the sun releasing its coronal mass ejection. NASA image credit
NASA reports that a solar storm in 1989 caused a 12 hour blackout in Quebec, Canada. The U.S. suffered a series of energy losses and was forced to shut down. NASA reports that 1859's Carrington Event, one of the most powerful solar storms ever recorded, knocked out telegraph systems and brought the aurora to Hawaii.
Murtagh stated, "When we look back on the extreme geomagnetic thunderstorms all the way back in the 1859 Carrington Event, we have concluded that they are all associated with multiple CMEs."
Space weather can be even more difficult to predict than weather on Earth's surface.
Scientists are still trying to understand the sun's workings. Murtagh said that data from NASA's Parker Solar Probe, and the European-American Solar Orbiter missions, are providing data that will aid scientists in tackling those mysteries, but it doesn't make forecasting easier at this time.
Murtagh stated that although we have some skills in forecasting the solar cycles, it is not a great skill. Therefore, it could easily become stronger. "The space weather industry is full of unknowns."
