 Hello, everyone from wherever you're joining. Thank you for being here today for this NCAR Explorer Series Conversation, understanding how we see our sun's atmosphere with Dr. Anna Malinushenko. My name is Dr. Dan Zitlow and I'm an Educational Designer here at the National Center for Atmospheric Research or NCAR, which is a world-leading organization dedicated to understanding per-system science. So that includes our atmosphere, weather, climate, or sun, and how all of these systems interact and impact society. I'm really glad that y'all could be with us today to learn more about some new results that may lead us to rethink how we measure and understand the atmosphere of our sun. For this event, you'll be able to ask Dr. Malinushenko questions throughout the conversation using the Slido platform. If you scroll down this web page, you can see the Slido window just below where you are seeing the live stream of video of this event. If you haven't already, go ahead and click on that green Join Event button, and then you can ask questions on the Q&A tab and answer poll questions on the Pulse tab, both of which are found in that blue bar across the top. Definitely be sure to join Slido to add your thoughts to our Work Lab question. What do you think of when you hear the atmosphere of our sun? Because we're going to be getting to that very soon. This lecture is also being recorded and will be available on the NCAR Explorer series website. With us today, we have NCAR scientist Dr. Anna Malinushenko from NCAR's High Altitude Observatory, or HAO. She received her PhD in solar physics from Montana State University in 2010, after which she completed two postdocs, one at the Lockheed Martin Solar and Astrophysics Lab and then another here at NCAR. Annie's research focuses on the magnetic field in the solar atmosphere. She's also a lead of a science working group focused on interplanetary coronal mass ejections in punch, which is an upcoming NASA mission for understanding how the mass and energy of the solar corona transform into solar wind. Annie, can you turn your camera and give us a quick hello before we check out our Work Lab question? Hello. Awesome. Paul and Brett, would you be able to share Slido for us so we can see what our audience is thinking about our Work Lab? Great. Some of the things that I'm seeing right now, so hot storms, really, really hot gas, hot. I'm getting a sense of maybe a very high temperature in our solar atmosphere. Chaotic, solar flares. Annie, what do you think about some of those results from our audience? They are all great. I'm loving all of them and I'm thrilled that the audience has those associations. They're all absolutely correct. I would like to point out that when you combine the word gas with the word really, really hot, you get a new word called plasma. But other than that, CME solar flares, you can think of them as storms, and they take place in the solar atmosphere, which isn't it really, really hot. It's a gas, so hot, it is magnetized. Awesome. Then I also see a few folks just added CMEs or coronal mass ejections. Yep. Great. So let's go ahead and dive into our conversation. So Annie, you work in the high-altitude observatory here at EMPAR. So can you tell us what is HAO, what research topics is the lab interested, and what is your role? Thank you. So HAO studies works on a range of topics basically in sun, earth system science, and they span from the solar to heliosphere to some of the impact of space weather on earth. So in the sun, we do study topics like long-term solar variability and coronal mass ejection initiation, interruption, and magnetic field and active regions in the interplanetary space. We do study the propagation of coronal mass ejections, and we impact on the earth areas. We study the impact of solar energetic particles on the upper atmosphere, and we studied the earth-magnetic tail and the atmosphere coupling with the mesosphere. All those topics, a lot of it is theory, but we also do have some observational facilities, such as monolores, solar observatory, and there are some eclipse expeditions, and there are some fabryperont interferometers that study the ionosphere and the upper atmosphere, and also, well, last but not least, we have the educational department and outreach. So I guess that's about it. As for my role in it, I am a project scientist, and I work mostly in solar and heliospheric areas, and I study in the solar areas, I study the magnetic field in the solar atmosphere or corona. You will hear the word corona a lot in this conversation. In the heliosphere, I study the propagation of interplanetary coronal mass ejections, and I am a working group of a common hot mass mission called punch. So it sounds like there's a tongue going on in HAO and even within your own research. So I have a follow-up question before we get to that. Just want to remind the audience, we actually have some poll questions for y'all to respond to, and we're about to come up to one very soon. It's the first time we've ever done an open response poll question, so we'll see how this works out. But we'd love to hear from you about, if you were promoted to a scientist today, what would you study about this on? But before we get to that, Annie, so how did you become interested in being a solar physicist and doing some of the work that you do? Well, from an early age, I knew I wanted to be a scientist, and the reason simply being is that both of my parents are scientists, and I just saw how much fun they have at their work, and I wanted to have as much fun. And I eventually converged into the physics area, because I like to understand how the world is made, and physics is a naturally interesting area, and there are a lot of fun puzzles in physics in general. And I mean, I guess in the research in general, I'm speaking about physics, because this is what I know most. You would think that scientists, or at least as a popular opinion, scientists are those nerdy people with eyeglasses, and really boring, know a lot. I do some boring stuff, super smart. Well, the truth is that science is solving fun puzzles. And I did get into the solar puzzles and solar area of research, in particular, through a program called Research Experience for Undergraduates. And this is something that is common around the United States, and that is an excellent opportunity to, well, so to speak, try before you buy, try different areas of scientific research over the summer holidays, and see if you like them, and, well, your time is paid, so that is also pleasant for an undergrad student. So I tried solar physics, and I liked it a lot. On top of fun puzzles that, like I said, I like to solve, there are a lot of stunning visuals. There's a lot of good physics. And I just figured that a lot of these researches, I get to program video games, and then I get to play them. So that was cool. That was so cool that I tried again the next summer, and again, and again. And here I am now, starting the sample time. Also, thanks for sharing that. Yeah, it's, I mean, I agree with you. There's lots of kind of fun questions that we can ask as scientists. And there's also lots of great ways to get involved even from a pretty early age. So moving into maybe thinking about, how can we actually study the sun? Paul and Brett, let's maybe pull up that first poll question about, if our audience was promoted to a scientist's day, given that we can't look directly at the sun, what would you want to study about the sun? And so looking at some of our answers, I'm seeing energy readings, use a sensor, like a camera with a filter, and then look at the output of the camera, satellites, images of the sun, coronagraphs, photographs, carefully. I like that one. What controls the solar cycle, satellite data? A new one just came in. I'm not totally sure. I guess using basic laws of physics and studying the things, the sun effects and changes in research and theory. Did any of them send out to you, Annie? Absolutely, all of them, including the word carefully. Yeah, I like that one too, especially with the the sunglass emoji afterward. Well, so since, speaking of carefully, since the sun is so bright and it's not safe for humans to look directly at the sun, so please never to look directly at the sun, how do scientists do this? Like how do we study the sun? Well, there are different ways to do that. And well, in those ways, largely speaking, they split into two different approaches. One approach is observations. The second approach is models. And speaking of observations, yes, the telescopes and telescopes are nothing more than gigantic photo cameras and video cameras with a lot of bits and pieces attached to them. And a lot of the telescopes are based on Earth. However, there are a lot of telescopes these days that are orbiting the Earth or even orbiting the sun or are even based on other planets. In fact, I have a picture here that I wanted to share. And it is also available on NASA website. And that is a share screen. And I am sharing my very browser so you can see the website at nasa.gov so you can go there and see for yourself. But this is basically a fleet of heliophysics observatories that are currently in space or in development. Now, why do we need to go to space? Well, we all know about the importance of sunscreen, right? So that we don't get burned, so that our skin doesn't get burned with ultraviolet and ultraviolet comes from the sun. So you would think that, okay, if a lot of interesting things on the sun are visible in ultraviolet, we should be able to study it from Earth, right? Well, the truth is that it is the solar disk that is bright enough to burn our skin even through the atmosphere. However, if we obscure the solar disk and get a coronagraph to study the atmosphere of the sun or the corona, it turns out that it is so faint and Earth atmosphere is so thick that it blocks a lot of good information. This is why to study the corona, we need to get beyond Earth atmosphere. And that is as far as observations. Now, regarding models, it's a philosophically very, very different approach. And here's how it works. So suppose you see me right now, right? And you see this little ball. It's actually a cat's toy and they allowed me to use it for a demonstration, but suppose I drop this ball and I mean, most of the audience have access to balls like this and you can drop it and study it for yourself. However, imagine that you were an alien and you lived on a different planet with different atmosphere and you have tentacles for arms and you don't have balls. You don't have balls like this and drop like this. So what do you do to study this? And you're so far away that you cannot ask me for this ball. So how do you study how the ball falls? Well, you make a physical model and here's how. You say, well, we know that there's gravity on Earth and we know that she is subject to such and such gravity and the ball is the ball weights such and such. And here is the diameter of the ball and how about we put all this into a computer? Remember I mentioned a program in a video game and then get into play for yourself. That's it, that's models. So putting all of this into the computer and just put a lot of physical laws into the computer and just make it a model. And the good part about this model is that it allows us an access for something that we cannot directly observe such as what happens to the ball beyond the screen. I mean, it falls into my palm, but you cannot see that with the model he might be able to guess that. The disadvantage of the models, of course, is that they show you only as much as you put in them. So you have to have a pretty good idea about physics to begin with before you start modeling. So those are two very different approaches to studying the sun. Great, yeah, as an undergrad, there was always a healthy competition, I feel like between the observationalists and the theorists, at least in my physics lab. And also just a quick note for folks in our virtual audience, some of the websites that Ani's gonna be showing us throughout this talk are available in Slido. So if you click on those three horizontal bars in the upper left-hand corner, if you click on that hamburger dropdown menu, you'll be able to see some of the websites that we're talking about. Cool, so moving into another audience poll question that we had. So speaking of some of these telescopes you had mentioned, both terrestrial and then up in our atmosphere, we were interested in asking our audience, you know, like what data do we collect or use to study the sun? And this was a poll question that you could choose multiple answers for. And it looks like the top answer was photographs of the sun followed by properties of interplanetary plasma and magnetic field near Earth. The third was looking at ice at Earth's poles. Number four came in at studying true rings and the last one was monitoring social media. So Ani, which of these are we able to currently collect data on in order to help study the sun? Well, all the top four, however, I must say, I mean, while the sun doesn't have its own direct representation in social media, so we cannot collect the data this way, but there are several very good social media outlets for NASA physics and for solar physics in general. Having said that, what scientists do, they take photographs of the sun in different wavelengths of light and also by combining different wavelengths of light, we can get information like magnetic field, for example, on the solar surface or velocity on the solar surface. And again, I file it under photographs because this is what in essence it is. Then the second topic is properties of interplanetary plasma and magnetic field near Earth. It is a mouthful, but what in essence it is, imagine a little box that does absolutely nothing but sits on Earth orbit, measures magnetic field and sends the information back to our facilities or measures the density of whatever is coming through it or the velocity, things like that. And it is not as detailed as the photograph, but it is not far away. It is measuring things that came from the sun and it is measuring them directly. So it has its uses and yeah, and it is used a lot. Now, looking at ice at Earth poles and starting tree rings is, well, those are two questions and they are correct actually. So scientists use, carbon-dating methods to study long-term solar variability so long that before we had, before we even thought how to look at the sun with a telescope before we were even humans. So those two methods are very good ways to get historic data. And scientists aside, we scientists love to post some of our results in social media. So I mean, even though it was intended to be a wrong question it is not wrong for public outreach in terms of. Awesome, so I'm gonna pause here because I see that we did have one question come in from our audience. So someone in our work cloud had mentioned CMEs. And so Jenna is asking what exactly is a coronal mass ejection? Coronal mass ejection, it's a bowl of plasma that is accelerated. First I will say it and then I will elaborate. So it is a blow of plasma that is erupted from the sun and that is flying away from the sun. And as for how it is erupted. Now here, the question is, I'm just looking to see if I have any hair buns with me. And apparently I do not. So you will have to use your imagination or, sorry, I have a couple of ropes here. Well, from my blinds. I'm just looking for something to create an impromptu demonstration and you don't have it. So here's the thing. So magnetic field lines in the sun, specifically in the solar atmosphere, you will not be wrong if you will think of them as a rubber bands. There is matter in those rubber bands and what they want to be, they want to be straight and they want to be far apart. So here's one rubber band. We're gonna have to imagine that this is a rubber band and I apologize for that. And here's the second rubber band. Both of them want to be straight. They do not want to cross. They do not like to cross. However, and this by the way is a model. It's a very, very simple model, but a model and it has its own limitations. So if we cross them and if we continue pressing on them, so now I twisted them just like that. I did not know if it makes sense. I twisted them just like that. Now, if I keep pressing on them, these ropes will break and the analogy actually will break too because what will happen, magnetic reconnection will happen. And all of a sudden, this part will become connected to this part and this part will become connected to that part. And they will become disconnected in the middle. And what will happen then is something like a slingshot. So slingshot. How do you make a slingshot? Okay, there we go. And imagine that there is a motor loaded right up here and it's been released and it's just flying away from the sun. Sometimes it hits earth. Sometimes it doesn't, but when it hits earth, there can be consequences. And I don't know that length explanation made sense. Yeah, that was great. And we'll also talk about some of those maybe societal impacts a little later in our conversation too. So thinking about our sun, I remember when I was in school and I remember learning about the solar loop. So like you said, this plasma, that's kind of arching off the surface of the sun. So can you talk to us a little bit about kind of our current understanding of the structure of the sun's atmosphere? So like what's the solar corona and what are solar loops? Yeah, I would love to. I mean, I could talk all day about it. Can I share my screen please right now? And again, I'm sharing a webpage with the data, with the recent and not so recent data from the sun from the atmospheric imaging assembly on board the solar dynamics observatory. And you can see the sun yesterday. This is what you work to see if you would look at the sun with a very, very, very strong filter with a very, very strong filter. So strong that it's safe for you, so strong that it's safe for your equipment. You will see a few sunspots boring. But if you were to look at the sun in ultraviolet, such as in 171 on extrem, going to click at 4K here. The same very area will suddenly be a lot less boring. And in fact, what's beneath the surface of the sun will appear dark and you will see those bright features on the surface of the sun. And there is magnetic field that comes into the game. I will show a few slides right now and hopefully that will help explain it. So this is the solar corona that I showed you before. By the way, I have a cool picture of the solar corona with the Earth to scale. So this is the sun and this is the Earth to scale and this is what coronal loops are like to scale. And by the way, they all appear in different colors. I'm switching between different colors. This is yellow and this is blue with yellow. And the truth is that those are false colors. The correct color is extreme ultraviolet. It's beyond our visible range. So what happens is that we get a black and white photograph in this extreme ultraviolet wavelength. And then we just put false colors in it for aesthetical purposes or to make some features more visible. So if we look at the solar corona and if we look at those interesting regions also called active regions, we will see those coronal loops which are thin, long, bright arches. And the idea is that they are hot plasma confined to what we call a magnetic flux tubes. And here is what I mean by that. So I did mention before that by combining several close wavelengths of light, we can get an image of a magnetic field on the sun. And this is what it looks like for the same very day. And this is the magnetic field in the same very area as of yesterday. And you can see that there are black and white regions and you can see, well, a little, not very well here, but you can see that those loops, those arches connect black and white areas on the solar surface. So those are the areas where magnetic field is directed towards us or away from us. So here is the idea. The solar atmosphere is so hot that the electrons are stripped off of atoms and the plasma becomes a magnetized gas. And once it becomes magnetized, becomes deeply entangled in the magnetic field. And there is magnetic field in the solar atmosphere and we cannot directly observe it, not easily and not very well, well, sometimes we can, but generally what we see is the surface. But based on the surface, we can make some models, magnetic field lines. And the plasma is, well, if we do compare the coronal loops with the lines of magnetic field, we see striking resemblance of the two. And this is kind of what allowed us to theorize that there are those things called magnetic flux chips and a lot of our physics supports this. We do know that plasma is what we call frozen in, which that is to say, if there is something, if there is something between two magnetic field lines, whatever happens to the something, generally it will try and remain between those two magnetic field lines forever. So those coronal loops, here's a paradigm. Something happens and the plasma becomes bright in a particular wavelength of light when it's either very dense or it's heated to just the right temperature or preferably both. So imagine that something right over here where my cursor is had heated the plasma to just the right temperature and it became very dense or something. So a little explosion had happened. And the topic of the coronal heating is still a very active topic of research. So what happens then is that the plasma we want to move about, it will become a hot gas if we want to expand, it won't move about, but it can only move about between the magnetic field lines that it was confined to in the first place. So a good analogy is if you have a field and if you dug two trenches in the field and if you filled one of them with water, the water will want to flow along one trench but it will not want to go to the neighboring trench. And this is our understanding about how plasma operates in general when it's heated to those temperatures when it's in those conditions. And now we see those loops and it's a no-brainer. So we think, well, there are those compact heating events. And those compact heating events heats those kind of garden hose-like structures. And yeah, and those garden hose-like structures are denser or hotter or just the right temperature than they're surrounding. And so they stand out and we see them. And those are called coronal loops. And the set of magnetic field lines about one such heating event, a tube-like, well, it kind of forms a tube-like volume and we tend to refer to it as to a magnetic flux tube. Awesome. And we actually had a question come in, somewhat related. So you were kind of talking about the outer layer of our sun, the solar atmosphere. So just wondering if the sun is a gas, what then does it mean to have a solar surface? Oh my God, that is a very good question. So, well, initially we saw those images of the sun like the ones I showed you earlier. And we saw that the sun is a blob of something. Sun is a blob of something and there is nothing around it. However, the sun is, well, on the other hand, the sun is a gas all the way through, right? So what does it mean that it has a surface? Well, the sun has a surface in the same sense that earth has a surface. Imagine yourself standing on the ground on the lawn. It's not like the ground is the divide between something, the ground and nothing. That is not true. The ground that you're standing on is a divide between the matter that is very, very dense, such as soil and the matter that is a lot less dense, such as air. And it just so happens that if you make a plot of the density versus distance from the earth's center, you will see that where exactly where the ground is, there is a drop in density from extremely high density to extremely low density. And, well, which is from extremely dense soil to low dense air. It turns out that exactly the same thing is happening in the sun. So if we are to look at the plot of density of the sun versus distance from the solar center, we will see an extremely sharp drop precisely where the solar surface is. And which is why we call it solar surface. So stuff below the solar surface is a lot more dense. Stuff above solar surface is a lot less dense. Now, the interesting part is, and of course it is plasma above the surface and it's plasma below the surface. And it is a magnetized gas above and below the surface. And as such, it is frozen in in a way that I just explained to you. But the difference in density leads to the difference in physical regimes. So in both above and below the surface, the plasma is very tightly connected to magnetic field lengths. However, below the surface, the plasma does whatever it wants to do, it floats around, it's turbulent, there's convection and magnetic field lengths have to follow the path of the plasma because of the frozen inconditions. Now, above the surface, there is so little plasma that it has no say. Magnetic field does whatever it wants, generally and plasma has to follow. Okay, I think I understand that. Yeah, that's interesting. Like, you know, what does it mean for something that's not solid to have a solid surface? Yeah, so thanks for that explanation. So moving maybe into some of the work that you've recently been doing. You know, it's maybe helping us rethink a little bit how we might understand the atmosphere of the sun. So could you walk us through that work? Yeah, so I would love to. So I will first want to say that I was always interested in the 3D structure of loops ever since I was a grad student. I'm going to share my screen again. Note how coronal loops overlap on this image. And the reason why is, I mean, the sun is not flat. The sun is like a bowl, right? The sun is a three-dimensional structure but it is the photograph that is flat. So if I can make a cutting edge styrofoam wire model and if I can cast a shadow on the backdrop on this model, this shadow is, well, in some ways analogous to what we see on the image on the laptop. So what we see is the solar coron is what we say optically thin in the sense that we can see right through it. And when we see right through it, different structures along our line of sight overlap. So I actually brought this model right over here. It had been buttered by several cats, but it is still alive. I've been always interested in the 3D structure. So if what we see is the shadow on the backdrop, the integral along the line of sight, it is the integrand that is very, very interesting. And I must say that it is the integrand that we need to understand to be able to understand the solar atmosphere. So I've been always interested in how to determine this integrand and what is the shape of the magnetic flux tubes. And for example, in our paper before this work, we looked at how magnetic flux tubes expand with the distance away from the sun. So imagine that those are two different poles of a bar magnet and magnetic field line spread apart. And what does it mean for the magnetic flux tubes? And we theorize that depending on different configurations of the magnetic field to the surface of the sun, magnetic flux tubes will have different cross-sectional properties in the solar atmosphere. But of course, this is just a simple model. We don't know how they really are in the sun. What we want to know is how they are on the image on the left. And we cannot go there directly, not just yet, although a recent Parker Solar probe mission is getting very, very close, but it's not getting close enough, which is where models come into the game. And before my work, there was a wonderful model of the solar atmosphere made by our own, well, the code was developed at NCOR. And there's a difference between a code and a numerical model. So a code is like a potter's wheel. And you can use the potter's wheel to make a beautiful pot, which is a beautiful model of something. So there was a code that contained a lot of the known physics of the sun that went a little bit below the surface and somewhat above the surface. And it was developed in NCOR at HAO, in fact. And later on, a group of scientists led by Lockheed Martin had used that code to, I'm going to show you another webpage, use this code to model a solar flare. And this is a video from an NCOR news release on the simulation. I will say simulation and by that, I mean this box, this little active region in the box. And the good part about this model is that we can look inside of it. So for me, it was like a gift. It was a little piece of the sun that was gift-ropped and given to me and they could study it. So it looks just like the sun. The flare looks very, very reasonable. And you know what? The model itself, the solar atmosphere looks very, very reasonable. Now, I'm going to show a very boring slide about this model. And this is a nitty gritty, nerdy details. And I don't want you to read all of it. I just wanted to show basically the box. The box went a little bit above the sun, a little bit above the surface, a little bit below the surface. And a lot of it was nice and as correct as we can only be. And it featured a flare and a lot of properties of this flare were correct. So if you remember this analogy about with the ball, the model contained the right time that the ball took to fall down and the model contained the right color of the ball. The model was just as squishy as the ball to make an analogy. So it was a good model. And then we looked at it and it contained a good realistic believable kernel loops. So in those images, panel E is the model and all other panels are actual real solar active regions. And it is hard to tell them apart. A trained ICANN, if you know what to look for, but I mean, in general, this model was very, very, very reasonable. And by the way, here's the same model here from the side. Again, panel E is the model and all other panels are actual real observations. So my next step was to be honest, I was initially interested in continuing this work in finding those corona loops in 3D and looking at the shape in cross-section. So how do we do this? Again, I did show you the slide before. Just remember the integral along the line of sight is this. How do we study the integrand? So this is part of the model. Suppose that we take a slice through the middle and suppose that we extract. So this is a numerical simulation. So it's a cube that has this many pixels in each direction. So how about we extract the middle slices pixels and look at it and look at the emission of this middle slice face on and see what we will see. So the image on the left shows a lot of kernel loops and we know that kernel loops are many plus tubes that are filled with emitting plasma. So that was kind of the expectation. And I just wanted to study the properties, the cross-sectional properties of those circles. And that was an expectation. This is what I saw. And to be honest, my first reaction was what? But it was immediately clear that we need to understand this further. So I made this movie to look at different slices in the volume to understand what's inside of it. And do you remember me saying that solar physics is like writing your own video game and I'm getting to play it? Well, it was a lot of fun making this video actually. And yeah, the very bottom panel, the black and white picture is what we call magnetogram is the magnetic field on the surface of the sun. White is pointing up, black is pointing down. There are some magnetic field lines just to guide your vision. The backdrop shows the line of sight integral. So analogous to the shadow on the backdrop. And then this moving plane is what we are interested in. The slice in the volume. And there are several things that I noticed here that immediately warranted more further study. So how do I pause right over here, for example? Yeah, so one part of doing research is describing your experience. And here's me describing my experience. On the backdrop, I see thin, long coronal loops. In the volume, what I see is a veil-like structure with wrinkles folds and a very, very complicated shape. And we did some further analysis and we found that it is where those wrinkles co-align with the line of sight that we see coronal loops. And that was actually that allowed us to understand what on earth is going on here or what on the sun is going on here. So this is part of the simulation. So this little bit on the left is actually this little coronal loop that was straightened out. And this is this volume that produced this coronal loop viewed from different angles. And you can see a whole lot more coronal loops there and they merge, blend into one another and the situation looks very, very complicated. Or we can rotate it in a different way. And here's the footprint of it. Do you see this little structure here that looks like a lightning symbol or like an archaic Greek leather copa? So here's the thing. Imagine that we're looking at it. Imagine there are two different observers that are looking at it from two different ways. Observer one will see two loops where those two bright pieces of the veil colline with our line of sight. Observer, well, in some background in between them, this middle part will be less bright because we're looking through it in a smaller depth, so to speak. Observer two will look at this middle part edge on and it will look at those two legs face on. So observer two will see one loop and background around. And this is what that loop was. And so what happens if we subtract the background, then we will be, then the two observers, you will think that we can do stereoscopic and look at it from two different directions, but the truth is that if we subtract background, which is a common technique, then we will be looking at two different portions of the coronal loop even. So this in essence is what the work is about. And it turns out that if we have a lot of features, this was just one feature and I walked you through it. If you have a lot of features, the situation becomes a whole lot more complicated. And it changes a lot about how we studied those features because we do study, for example, how bright they are as a function of their height and from that we can study how density drops with height and the solar atmosphere becomes more rarified with height just like Earth's atmosphere. And we can study it and from how much dimmer they become with height we can figure out how dense the solar atmosphere, how quickly it becomes rarified with height. Now if what we're looking at are wrinkles in a veil curtain, then we can no longer do this or we need to do this in a different way. So this is what the work is about and well, the term of the work is coronal veil because and again, I'm going back to this cutting edge styrofoam model and here's the second half of it. Look at the shadow and the backdrop in both cases on both photographs there are dark features or in case of the sunlight features that can be called coronal loops, but in one case they are real in the sense that there are coherent compact magnetic flux tubes that brought them to existence. And in the second case, there is an extended veil-like structure that emits light and it's the wrinkles in the structure that are responsible for bringing the loops into existence. This is pretty cool, this is super cool. Yeah, so with this, I guess coronal veil hypothesis so if I'm understanding correctly, basically we have material in our solar surface that is basically there's like wrinkles in these sheets, that's kind of potentially producing some of these structures and then I guess with the server thing it could also just be a function of like how we're using our solar telescopes to maybe look at some of this stuff too. Am I interpreting that right? Well, I mean, solar telescopes, they are essentially big gigantic cameras, very specialized cameras. And I mean, if I have a camera then what are the many ways in which I can use it well? I mean, I point it and shoot it, right? It is a question of how we interpret the observations and we might need to interpret them in a whole different way to understand what's going on. Great, speaking of interpretation, I know you had like a philosophical graphic, do we wanna talk about that now or did we wanna take a question from the audience? Or are there questions from the audience? I'm happy to answer them. We did have one come in from Eric who is asking, why is the corona so much hotter than the solar surface? That or in other ways or in other words, what is the solar corona? Because it is indeed many, many times hotter than the solar surface. This is an open question. And if you're interested in joining us in solar physics that is still an open puzzle, there are different models, but which of them, if any is correct, we do not know. But for sure magnetic field is involved. For sure magnetic connection is involved somehow. And that's about all I can say. So come study solar physics and find out. That's cool. Yeah, there's definitely some big questions out there that we're still trying to understand. Yeah, so going back to maybe this idea of observation and perspective. And I know you have a fun kind of philosophical discussion on science if we wanted to dive into that. Oh sure. And it has to do with that sun is very far away and it's very, very different from what we have experienced on Earth. So here's a bit of philosophy. Imagine, where is my PowerPoint slides? Oh, there we go. Imagine those two garments from Earth. And imagine those two aliens who have absolutely no idea of what this are and how we use them. Those aliens will reconstruct an appearance of a human in a way that resembles their own appearance. The point of this cartoon is our prior experience shapes our interpretation of what we experience right now. And we are things are used a lot more to solid objects like bar magnets or like metal shavings. We are not used to anything like what's going on in the sun. So we looked at the simulation. We found out that there are not many, well, garden hose like, so to speak, compact magnetic flux tubes. So we found veils. Now what happens in the real active region? I mean, a model is a model that has limitations. We think it's a pretty good model, but it's still just a model. So what happens in the sun? And that is an open question. Yeah, and I love this discussion, right? That, you know, even as scientists, we're making all these observations and we're drawing our kind of past experiences to help interpret some of these data. Great, so I don't see any questions from the audience right now. So maybe we can move into one of our next poll questions. So as we kind of talk about the societal importance of understanding, you know, the structure of the solar atmosphere, maybe if we can show that audience poll question that was asking, you know, what systems on earth can be impacted by the sun's activity? And the top answer I see there is our power grid. I think that's one that maybe many of us have had experience with, you know, our power grid is being affected, but there's a lot of selectively going on. The tide for a second, we had satellite communications as well as humans in space, such as in the International Space Station. In third is crop yields. And then last was pigeon racing. So did you have any comments on any of those responses? Well, I have to say it was a lot of fun coming up with those options and coming up with the right answers was easy. It was difficult to come up with the wrong answer. And the wrong answer here by design is crop yields. All other answers are correct. And our power grid can suffer a severe impact from a coronal mass ejection should it hit earth. Oh, can you actually bring the slide of questions back, please? Yeah, so our power grid will have a severe impact if something arrives from the sun and we're not prepared. Well, our satellite communications will be severely impact also. And, you know, that's kind of a common knowledge. And the energetic particles are obviously harmful for humans in space who do not have atmosphere to protect them. Now, here comes the fun part. It turns out that pigeons use Earth magnetic field to navigate about. So people who handle pigeons professionally, they actually watch for geomagnetic indices because it is important for birds orientation. And live and learn. I learned about this myself just this year. Now crop yields, well, I mean, obviously if we do not have a power grid, if we don't have our trucks that are filled with fuel and fertilizers and the information on how to fertilize the fields that would impact the crop yields. But this impact is not direct. And as for a direct impact, there is no time aware of. There is not a physical mechanism of time aware of that would impact the yield of wheat of the field. So that was a trick question. And of course, here comes another caveat. Of course, if something happens with the sun, if the sun gets a whole lot dimmer all of a sudden, that will impact crop yields. But this is not what happens in extreme space weather events. What happens is that a lot of stuff suddenly hits the Earth and impacts the Earth magnetic sphere and plays tricks with the Earth magnetic field and those things are ultimately short lived. Yeah. Great. I see a couple more questions that came in. So one is from Brian. And I think it's maybe building on Eric's question previously about some things we don't yet understand about the sun. But maybe besides the solar veil, what other mysteries about the sun are you most interested in studying? Oh my God. The coronal heating question for absolutely sure. And this is such a big topic because you think there's a small question like let's just go and find a mechanism that hits the sun. No, it's like you open a Pandora box. Okay, magnetic field is responsible. Responsible how? Responsible in what ways? Here's one way that can be responsible. And then there's a lot of research about this one way and here's another way there's a lot of research in this other way and how to find out which one is correct. And yeah, that is an extremely important topic and this is an extremely interesting topic for me personally. Another topic that is interesting for me personally is how magnetic field is structured in the solar atmosphere. I did show you some magnetic field lens and most of them were large far away from the sun by design so that you can see the solar curvature and all, but also if you go further from the sun those simple models are more correct. However, if you zoom into particular active regions magnetic field lens twist and intertwine and I'm very interested in how they're doing this and how it evolves and what happens to magnetic flux tubes. I am also interested in what happens to the coronal mass ejections as they propagate. Do they, do they squash and become like a jellyfish? For example, how does their inner structure change? And as they fly through the interplanetary magnetic field it's one of the topics that we're currently investigating. As they travel through the interplanetary media they gather material like a snow plow effect and this material, we can actually observe it and it's very difficult to disentangle it from the coronal mass ejection itself. So this topic is also a very high interest to me. And then we have another question that came in from Melissa asking the Parker Solar Probe was able to make contact with the corona. Were we able to get info from this encounter that we weren't able to observe before? Yes, I must, I will say a few words however. I must say that this is not exactly my specialty. So I will say what I do know. And what I do know is that we got a few extremely high resolution images in the solar corona. That is one thing. The second thing is we saw a lot of turbulence in the solar wind. So those are the two topics that I know off the top of my head. Great. And we have a question here from Sherry which I think also leaves us, it's a great segue into our last question. Sherry is wondering, what did you major in at university to get into solar physics? And building on that for our students in our virtual audience here, do you have any advice for them for becoming a solar physicist? I personally measured in physics. Some of my colleagues have measured in math. However, there are many different ways into solar physics. And some of my colleagues have measured in computer sciences and they helped us build this data environment in which people like me thrive. So there are different ways into it but it's basically physics math. Computer sciences to come and help us build better models, build better environments. Engineers help us build telescopes. So that is another area of study. That is another area that and it leads to solar physics eventually. And as for the advice that I can give, well, there are several. One is try to have fun as you major in whatever that you're majoring in. Look for puzzles, look for questions. Look at how your professors solve those questions because once you become a researcher there will be no answers that anybody knows. You will have to find answers. And try and see if you're enjoying this or that. And I highly recommend the research experience for undergraduate programs throughout the United States. And last but not least, I have to say that if somebody tells you that you are not good enough because you're a woman or because you're, I don't know, Hispanic or because you have a disability do not listen to them. You are absolutely good enough. The only qualifier is whether you like learning. If you do enjoy learning, you're absolutely qualified. So, yeah. Definitely, those are great words I think to end on. So, Annie, thank you so much for being here today to chat about the sun and just the really, really cool work that you're doing here at NCAR. It is my pleasure. Thank you for having me here. And definitely thank you to our team behind the scenes, Paul, Brett and Aliyah, for supporting this conversation today. If you're interested in more NCAR Explorer series events, definitely check out our website for upcoming lectures and conversations and also view recordings of past events. And so with that, I hope to see y'all next time and I hope you have a great rest of your day.