In May, the National Oceanic and Atmospheric Administration issued a watch for a possible solar storm. A gigantic cluster of spots on the sun was flaring and expelling material headed straight toward Earth.
Hours later, the watch was replaced by a warning: A storm classified as G4 — on a “G” scale of 1 to 5 — was coming. That weekend, the solar activity was even stronger, creating northern lights that stunned people as far south as Arizona. Behind the scenes, space weather scientists were working around the clock to make sure that the potential for catastrophic effects, like widespread power outages or communication blackouts, remained at a minimum.
According to Mike Bettwy, a meteorologist and the operations chief for NOAA’s Space Weather Prediction Center, a lack of data can make solar storm forecasting difficult. The agency is working to change that: On Tuesday, SpaceX is scheduled to launch the agency’s GOES-U spacecraft, the latest in a family of satellites designed to monitor the sun’s impact on our atmosphere, particularly as it approaches a peak in its activity cycle.
Mr. Bettwy spoke with The New York Times about what goes into predicting space weather, and the challenge of trying to make sense of an often unpredictable sun. This conversation has been edited and condensed for clarity.
How does the space weather forecasting system work?
Our office in Boulder is one of many regional watch centers worldwide. There are others in Sweden, the United Kingdom and Australia. We collaborate by comparing and sharing our forecast models, which are all slightly different.
Similar to terrestrial weather, storm watches go out first, and a warning is issued when we are more confident about what is coming. Alerts go out when the weather has actually been observed.
We regularly work with NASA’s Moon to Mars Space Weather Analysis Office, which does a lot of computer modeling of the sun. And we give a heads up to NASA’s Space Radiation Analysis Group anytime there might be potential radiation exposure to astronauts on the International Space Station.
We also talk with the North America Electric Reliability Corporation, which makes sure the power grid stays up, every day about what might be coming. They then inform their own subsidiaries throughout the country and Canada.
What instruments are used to monitor solar activity?
The Solar Ultraviolet Imager, which is on the GOES-16 satellite, is what we use most. It monitors temperatures on the surface of the sun, and shows us the evolution of sunspots and their surrounding environments.
Two other critical satellites are NASA’s Advanced Composition Explorer and our Deep Space Climate Observatory. These are about a million miles out from Earth. That sounds far, but there are actually 93 million miles between us and the sun, and the plasma that flows from it travels at high speeds. By the time it reaches these satellites, we really only have about an hour or less to know that something is going to hit us.
There is also a system of magnetometers, sensors that detect changes in the sun’s magnetic field, scattered around the world.
How might the forecasting system be improved?
More satellites would be incredibly helpful. Ideally — and this won’t ever happen, because it’s not financially attainable — we’d have a satellite every million miles between Earth and the sun. With more satellites, we could see how solar material evolves and changes as it approaches us.
The new GOES-U satellite will have a coronagraph to take images of the sun, and get us higher resolution data to help with forecasting.
Better space weather modeling is also underway. With terrestrial weather, there’s loads of data. We are just absolutely spoiled with tons of observations. With space weather, we just don’t have that. It’s hard to make tough decisions with only one or two pieces of key data.
We are also working on changing our watch, warning and alert system. Right now, we don’t actually have the ability to issue a G5 watch. When we issue a G4 watch, it technically means G4 or greater. And with warnings, we can only issue up to a G3.
We’re collaborating with our international partners to revise this. Not only will it give us the ability to communicate more precisely, but it will be easier for folks without a technical background to understand what we are talking about.
Isn’t it scary knowing that we are at the whims of an unpredictable sun?
It can be daunting. But over the past decades, we’ve learned how to live with the sun. We’ve learned its power and what it can do. Most agencies have appropriate precautions in place to deal with it.
When you get a really intense storm, there is always the possibility that there will be a greater impact than what we have planned for. And that’s the part that keeps us up at night. We want to make sure that even during a worst-case scenario, everything will be OK.
What is the worst-case scenario?
The Carrington Event of 1859 is like the granddaddy of events when it comes to space weather. It was the most intense geomagnetic storm ever recorded, with widespread impact on communications across the globe.
We live in a different world now. Technology has come a long way since then. So that’s what we are trying to prepare for. If we have another Carrington Event, we want our infrastructure — the power grid, satellites, aviation and the internet — to remain, for the most part, functional.
What should we expect as the sun approaches maximum activity?
The sun is definitely entering its more active phase. A few days after the last solar storm, we had one of the strongest flares we’ve seen since 2005. It came from the same sunspot cluster, right before it rotated off the west side of the sun.
But we don’t know when solar maximum occurs until after it has happened. The overall consensus is that it will be between the end of 2024 and early 2026. Over the next couple of years, the probability of getting more G4 events is quite high. G5 activity is a little more uncertain, but the chances of seeing it again is possible.
You can prepare for space weather the same way you would for thunderstorm or tornado season. Have emergency kits ready to go. Be ready for power outages and interruptions.
I was working at NASA during the Halloween storm of 2003, and my biggest takeaway from it was that it could have been worse. Now, more than 20 years later, our overall preparedness is even greater. So even if we got a more significant event than what we saw in early May, I’d like to think the ramifications will be fairly minimal.