Dr. Liz MacDonald Talks Aurora, Space Weather, And Her Citizen-Science Project, Aurorasaurus [SCIENCE WORLD REPORT EXCLUSIVE INTERVIEW]
Dr. Liz MacDonald has been working as a research astrophysicist in the field for more than a decade. She's worked on numerous satellite missions, focusing mainly on the building of satellites and other hardware, and is also active in interpretation of the data received by these instruments. Employed by NASA since 2014, she's in the Heliophysics division, studying the geomagnetic forces that interact with the Earth's magnetic field, and wave-particle interactions.
More specifically, MacDonald has studied the aurora borealis, commonly known as the Northern Lights, a powerful and stunning phenomenon that paints the night sky with vibrant streaks of of red and green. Two years before joining NASA, she founded a project called Aurorasaurus, a National Science Foundation-funded citizen-science project that helps aurora-chasers and hobbyists alike learn about and track the Northern Lights. After gaining some ground recently, the project recently launched an app, available on iTunes and Google Play.
The aurora are a part of what's known as space weather, a branch of space physics that examines the conditions in the solar system, specifically the space surrounding Earth, including solar wind plasma and conditions in the ionosphere. Space weather and the aurora are directly affected by the Sun's magnetic field, which flips its polarity on an 11-year cycle, a cycle of which we are currently in a several-year peak.
MacDonald has focused on aurora since she was in college, and has spent the better part of a decade searching for answers about how they're formed and what affects them. Recently, she talked to us here at Science World Report about them, Aurorasaurus, and space weather in general.
SWR: You're obviously very interested in the aurora. So what about them drew you to them?
MacDonald: It's one of the most beautiful natural phenomena on Earth. It moves, it's very dynamic and it's just beautiful. You can look up at the sky and your jaw will drop at its greens and pinks and reds. It's sometimes not as dynamic - the camera will pick up more than your eye will see - but it's just a spectacular sight, especially with the motion. I started studying the aurora actually when I was in college, through a research project, and I had initially not really liked physics at all. Then I got a research position in a geophysics department where they did some studies of aurora, and I suddenly learned that the aurora is all controlled by physics of the near-Earth space environment and the interactions of these charged particles with the Earth's magnetic field lines - there are all kinds of beautiful, complex processes that happen, and ultimately they cause the Northern Lights. Understanding parts of that system really appealed to me for further study, so I continued on in this field.
What gave you the idea to start Aurorasaurus?
Well it was actually one of these events - we call them geomagnetic storms - that as a scientist, as a space scientist, I can look at the data from some of the satellites. We have a couple of satellites that give us some warning of how large of an event or storm is going to happen, and we use data from about a million miles upstream of Earth to get about a one hour warning of the incoming solar material and the strength of that.
So, as a scientist, I'm looking at that data and seeing that there's a really good event going on in late October 2011. I was at home in New Mexico - and you can very, very rarely see aurora in New Mexico - and I didn't think this event was going to last long enough to get to New Mexico. But I had been hearing about Twitter, and so that was how I joined Twitter and started to search for the Northern Lights and saw that people were actually reporting that they had seen it. This particular event coincided very well with darkness on the eastern seaboard, and it was also a type of rare aurora that was more red than usual. The red we know comes from particles in space hitting higher up in the atmosphere - we don't fully know why some storms have more red than green - but when you have a storm that has a lot of red aurora, it can be visible further away.
This storm was seen even as far south as Alabama. And that's a whole lot of populated area, so there were thousands of tweets about it. So basically I got the idea to put these tweets on a map, and from there we added the citizen-science element, which is where [you can get involved] if you're not on Twitter (and a lot of the scientists in my field are not all on Twitter), but might watch the night sky more closely than most people. So they can go to our site and deliberately report that they've seen the aurora, make an archive, upload a photo, and fill out a form about where and when they saw it. So we use these reports to ground truth some of our very coarse models of where the aurora can be seen, and also to give people alerts in real-time that other people close to them are reporting aurora.
Those storms obviously cause and affect the aurora, so is it like the bigger the storm, the bigger the aurora? How does it affect the colors, and the range?
There's a whole spectrum of different storms and strengths as well, and so the largest storms are the rarest, and they also have the highest probability for other potentially costly infrastructure damages. From power grids to satellites in orbit, to GPS systems and things that rely on communication with space. And there's a whole variety of space-weather effects. Our platform is in improving knowledge of auroral visibility for the public, so we don't focus on other space-weather effects for those other industries, which are covered by NOAA - the Space Weather Prediction Center at NOAA.
But getting back to your question, there's a whole variety of things that drive the strength of the storm, staring with what's emitted on the Sun - and that's 93 million miles away. So we have some satellites that observe what's happening there, but then just like traditional weather forecasting, there's some input data and then we have some models for weather that are going to see how that's going to impact Earth. And those models have high uncertainty. We're well behind traditional weather forecasting because we have so few satellites and space is so large. So it's a hard problem. But the aurora can actually be seen more widely, more often than people think because there's a big communication gap - basically [with Aurorasaurus] we're trying to put information about when it can likely be seen in the hands of people. So you could be in New Jersey, and maybe you desperately or really want to see it, so you really want to make a long drive or go out to the country and you're really dedicated. So this should help you know when there's a really good chance to be doing that, or get an alert when other people are seeing it, so that you're not just getting lucky. Because that's what often happens. If you might be out camping in the middle of nowhere or something like that you might have a chance to see it. But now that we have all these technologies, we can try to improve the communication about when it's visible. That's what we're trying to do.
One thing we're trying to do with this is, we have this - the aurora happens very high up in the atmosphere, so the model shows where the aurora should be overhead. But then you can see it further south, to the northern horizon, and that is estimated by this red line that's on the map. So we're asking people to help report and verify to improve that view line. So all of these observations can be studied and compared to the view line, which helps us build better models for people and for some of the other space-weather interests built around aurora.
I saw today that you were tweeting about how you're looking for more representation in Australia.
So right now we have a network of scientists who are volunteering their time to help explain what they do to some of the community members who are interested, we have a blog that people are writing posts about that, and we also want to expand that network to include what I'm calling "aurora science ambassadors" because there are a lot of local groups, and a bunch of them are organized on Facebook - because that's a great platform for doing that - where people are helping each other learn how to photograph the aurora and where to go. So getting those local leaders involved with our network really helps encourage people to report. So that's a general kind of citizen-science practice. So we want to get more involved with those local groups, and we started to have sort of connections with the groups in Canada and Alaska, so that's where we're going with the Southern Hemisphere as well. Our website works as predictions for the Southern Hemisphere as well, and we have had reports, but we don't have as much of a community there.
What's the most difficult part about getting people involved?
I'm kind of a hardware person in our field, I've worked on satellite instruments, and I actually didn't know how difficult building software is. I didn't write the code or build the apps, but we specified it and we had to make a lot of design choices, and you know, we're happy and pleased with what we have, but it's never going to work perfectly for everyone. But we've seen great growth so far and it's continuing to build momentum and grow on its own so I think we're really excited about gather more observations. The marketing is hard, I think. People want to share pretty pictures, and we're asking them to do a little more on this unfamiliar platform. But we've seen a good response so far and it's growing so far. We're watching it grow and that's exciting.
So from your experience, which you clearly have a lot of, what would you say - or where would you say - is the best place or time to be to actually get to see the aurora?
That's the question we always get, and that's the hardest one to answer as a scientist because the activity is so variable. We can't predict the activity [that took place] in Calgary last night, so I wouldn't tell you to head to Calgary in a week or anything like that. There are some populated areas that are further north that are under where I kind of call it the "everyday auroral oval" because it really is an oval centered on the magnetic pole. Usually you can see it; the everyday aurora further north is actually incredibly spectacular. So there are places like Fairbanks, Alaska; Yellowknife, [Northwestern Territories,] Canada; all of Iceland; and places in Scandinavia where there are really excellent places to go.
The activity is from the Sun, which has a several-year peak, and we're kind of coming out of that peak now. So March and September are sort of the best times to go to the Northern Hemisphere and see these exotic locations because there's enough light that you can still do other things. Also, traditionally in the spring and the fall, there's a little bit more aurora than usual because of the tilt of the Earth and the way that lines up the Sun's magnetic field and the Earth's magnetic field, which needs to couple and transfer energy from one to the other to drive good auroral displays. But basically you need four-plus nights in one of those locations to have a good chance at seeing it, where normal weather is not going to affect your chances too much. Then you can use our app to report your location or your usual location and you can report to us, and we'll put your observations on the map, use that for science, and use that to help other people report that they've seen aurora too.
Obviously you've seen a lot, you've been working in this field for a while. So what do you still want to learn as far as the aurora go, or space weather wise? What're you specifically aiming to learn now?
So there's still a lot we don't understand about auroras and how their produced in space. They're so dynamic, and they have some characteristic motions that we understand, but then they explode and race across the sky. That is likely caused by plasma instabilities hundreds of thousands of miles away along the magnetic field lines in space. So there are a lot of those connections that we still are making missions and observations to put those two things together. So our aurora models, as I said, are coarse. They don't predict the specific forms or colors or these instabilities that you would see. I'm really interested in how we can use these new citizen science observations in real time to basically make an improved model of the auroras, so that's what we're aiming for.
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