How Do You Science | Meet a Polar Scientist

Today I'm talking with Von Walden, an atmospheric scientist at Washington State University.

• Hear about Earth's bubble of gases AKA the atmosphere
• Learn why clouds can be weird in the polar regions
• Find out what an expert thinks about climate change—and how optimistic he is about the future

Resources You Can Use

• Check out AMNH's climate change resources
• Watch these polar bear cams
• Learn more about the polar regions
• Find out more about clouds and make a cloud in a jar

As always, submit burning questions at askdruniverse.wsu.edu. Who knows where your questions will take us next.

Transcript

Dr. Universe: Hey, friends. I'm Dr. Universe, and if you're anything like me, you've got lots of big questions about our world. Today I'm talking with Von Walden. He's an atmospheric scientist at Washington State University. We'll talk about the big bubble of gas around the Earth called the atmosphere. We'll talk about what it's like to work in the polar regions where it's super cold and there might even be polar bears. And we'll talk a little bit about climate change.

Dr. Universe: I can't wait for you to hear all about it. Let's get started. Can we talk about what atmospheric science is?

Von Walden: That's true. Yeah, so this is different than being, like, a weather person on the news. Those people are called meteorologists because they study meteorology, and meteorology is weather. As an atmospheric scientist, I'm interested in physical processes that occur in the atmosphere.

Von Walden: So, like how clouds form, or what makes the humidity go up and down, or what makes the temperature go up and down. And, in particular, I'm also interested in how the atmosphere interacts with the surface.

Dr. Universe: When we talk about the atmosphere, do we mean the bubble or envelope or blanket of gases that are around the Earth?

Von Walden: Yep. That's exactly right. Because of gravity, the Earth has gases that are gravitationally attracted to the Earth. The Earth is a very big object, and it's very heavy, and so these gases, they're bound to our Earth just like we are. You know, if you jump up, you come back down to Earth.

Von Walden: To some degree, the gases are working the same way. They're bound to the Earth. And there's very little loss of gas out to outer space from Earth. There's a little bit of hydrogen that leaks out, or light gases, but basically all the mass we have on our Earth and in the atmosphere is pretty much all we're gonna get.

Von Walden: That gas is composed primarily of nitrogen and oxygen. That makes up about 99% of the atmosphere. The other major constituent of the gas is water vapor, although it has a pretty small concentration. But in our daily lives, we see that water all the time.

Von Walden: That's what clouds are made out of. Clouds are made out of either liquid water droplets or they're made out of solid ice crystals. What I'm interested in as an atmospheric scientist is when do these clouds form and under what conditions, and how do they affect the surface in terms of the energy and the mass, like, any precipitation that falls?

Dr. Universe: I was gonna ask for an example of something you study, but it sounds like how clouds form is an example?

Von Walden: I am mostly interested in polar clouds, so I have traveled to both the Antarctic and the Arctic on several field experiments to install instruments that measure properties of the atmosphere, and one of the primary things we're interested in is clouds.

Von Walden: So, not only am I interested in how clouds form, I'm just interested in what they're made of. So, at the beginning of my career, one of the very cool things that my small group of polar atmospheric scientists discovered was that there are a lot of water clouds in the polar regions that are below freezing.

Von Walden: They're called supercooled water clouds, and that's a pretty super cool thing to study. And the reason why they can exist below freezing is because water droplets need something to form on, and in the Arctic and the Antarctic, the atmosphere's very, very clean.

Von Walden: There's not a lot of what we call cloud condensation nuclei— basically kinda junk in the air that the water droplet can form on. There's a lot of cloud condensation nuclei. There are very few ice nuclei. So, the water droplets form, but they never go to an ice crystal. That's why we have a lot of these supercooled water clouds.

Dr. Universe: Because there's not a lot of dirt or dust or whatever in the atmosphere, what you're saying is that the water droplets inside the clouds at the polar regions might not have something to latch onto to form an ice crystal?

Von Walden: Yeah. Right.

Dr. Universe: So, it's liquid water, even though it's below freezing and should be ice?

Von Walden: Yes.

Dr. Universe: Wow.

Von Walden: A lot of times what we do is we do remote sensing of the clouds from the ground. You know, when you turn on the news at night you see radar images— they call it a Doppler radar a lot of times. The weather people, the meteorologists, will say that. Well, we have radars and other instruments that we use, and those allow us to detect what we call the phase of the cloud, whether they're water or ice.

Von Walden: And so, we can see that these water clouds are forming, but they aren't what we call nucleating over to ice and turning into an ice cloud. And so, I measured at the South Pole back early in my career, I measured a supercooled water cloud, remote sensing, and then I also had a balloon that flew up into the clouds, so I had some validation.

Von Walden: And I measured supercooled water droplets at minus 32 degrees Celsius, which is way, way, way below freezing.

Dr. Universe: Wow, that's so cool.

Von Walden: And then very quickly-

Dr. Universe: I mean, literally.

Von Walden: Yeah, yeah, it's very cool. And then I measured it for a while. I had this balloon instrument that was basically videotaping the cloud droplets, and then there was a period of time, I don't know, maybe a half an hour when the only thing that we were measuring were these water droplets, and then all of a sudden, pfft, it just went to ice.

Von Walden: And it's like, somehow, it just all of a sudden, it just turned from a water cloud to an ice cloud. That's kind of in a nutshell what I'm interested in as an atmospheric scientist, or one of the things that I'm interested in. The other thing is that water clouds trap a lot more heat towards the surface than do ice clouds.

Von Walden: So understanding how different clouds around the planet impact what's called the surface radiation budget. The energy budget at the surface really tells us a lot about how different clouds affect the global surface energy balance, which is super important for understanding climate change, for instance.

Dr. Universe: Can you help me understand what that means—the global surface energy balance?

Von Walden: Yeah. So our atmosphere's very, very important to life on Earth. If we did an experiment where we were able to just remove all the gas from the atmosphere for a day, our Earth would rapidly cool off, and if it came into equilibrium, with the energy we get from our Sun, we'd be a frozen rock.

Von Walden: Our surface temperature would plummet down to well below freezing, and the oceans would start to freeze. So our atmosphere is very, very important for life. It provides what has been termed a greenhouse effect. So if it wasn't for the natural greenhouse effect on Earth, life would not be present here.

Von Walden: A good example is Mars. Mars had an atmosphere, but it lost it. And in fact, most of Mars's atmosphere is carbon dioxide, which is a powerful greenhouse gas, but there's so little carbon dioxide that there's basically no atmosphere, and some very, very tenuous atmosphere. So that planet is a frozen rock basically, and any liquid water that existed is frozen somewhere in the surface likely.

Von Walden: But on Earth, we have this beautiful situation where our greenhouse effect is just right so that it keeps a lot of our planet as liquid water, at least at this time in Earth's history. So the greenhouse gases, they absorb heat from the Earth and keep the planet warm. The only energy source that we really get is from the Sun.

Von Walden: So the Sun's radiation comes in and heats the Earth, and that heats the atmosphere, and then our atmosphere heats the Earth some more. And if it wasn't for the atmosphere and the greenhouse effect, we wouldn't be at this wonderful temperature where we have oceans that are blue instead of frozen.

Dr. Universe: It's interesting because I feel like often we think about greenhouse effect in kind of negative ways, but it's interesting to talk about it as like, oh, it's also kind of the jacket that the Earth wears that keeps it from freezing to death.

Von Walden: That's absolutely true. I was very explicit in using the term the natural greenhouse effect because what I meant by that was for the whole course of Earth's history, before there was a human influence on the atmosphere, there's been natural fluctuations of the greenhouse gases in the atmosphere.

Von Walden: And this is studied through what's called paleoclimatology, old climate. So that's a fascinating area of science where they're like detectives. They use ice cores, and they drill into the ice. They drill into the ocean floor. They drill into trees. They use all kinds of evidence to tell us how climate varied in the past.

Von Walden: So we have a very clear understanding of how climate has naturally changed and why, for the most part. However, in the past 250 years, humans have undoubtedly impacted our atmosphere by increasing the greenhouse gases. So we have a manmade influence on our atmosphere now that's increasing that protective blanket and therefore warming our planet.

Von Walden: That's well-accepted science at this point—that there is a human cause to increased unnatural climate change. That extra climate change is sometimes called global warming because currently it is causing our planet to warm. I wanna make it very clear that the world scientific community agree that that is happening.

Von Walden: There's no scientific debate about that. It's very, very well-established science. So a lot of times you'll hear on the news about the debate of climate change, but it's not debating the science. It's debating what we should do about it.

Dr. Universe: When you go to the polar regions to study this stuff, how cold is it? What are you wearing?

Von Walden: Yeah. So I've gotten really good at this. So the first time that I went to the polar regions was in 1990 as a graduate student. It's hard to believe now, but I was in my late 20s, and I didn't really know what to expect. I was legitimately worried about the conditions.

Von Walden: But I traveled down to Antarctica through New Zealand, and the US have a place there where they give you gear. So, you spend like two or three hours sitting there trying on different clothes—different types of boots, gloves, hats, and I literally had two large duffel bags full of what are called ECW, extra cold weather gear.

Von Walden: And so that kinda taught me what I should have, so now, when I go to Greenland, I just have my own small duffel bag with exactly what I need. But just to give you an indication, we did a field experiment last May where we went up on the ice sheet of Greenland, and the first night we were there, we were camping in tents, and it was about minus 35 Celsius.

Von Walden: So that's in May.

Dr. Universe: Oh, wow.

Von Walden: So, minus 30 Celsius is minus 22 Fahrenheit, so it was minus 22 Fahrenheit that night. The funniest thing about this, though, is that earlier in that winter, we had a cold spell here in Moscow where the temperatures went down to about minus 20 Fahrenheit, so I set up my tent in my backyard, and I took all my pads that I sleep on, and then I have a big down sleeping bag, and then I have a down blanket that I put over me.

Von Walden: So, I went out in the backyard and slept out that night just to test my sleep gear, and I think my neighbors thought I was absolutely crazy.

Dr. Universe: You're like the only one in the neighborhood leaving your toasty, warm, cozy house to go sleep in the snow.

Von Walden: All for science, all for science.

Dr. Universe: I have a question, but you can stop me if this is too rude. You're sleeping in a tent, it's the middle of the night, it's very cold, you're in the polar regions, and you wake up and you need to use the bathroom. Are you leaving your tent?

Von Walden: So, when I was younger, I would. Now, I don't. There are a couple of things that I've done over the years as I've gotten older and maybe smarter, and it all involves Nalgene water bottles, like a plastic water bottle. So, before I go to bed, I'll boil some water, like in the tea kettle, and I'll put two of these bottles, and I'll walk out to my tent, and I throw them into my bed.

Von Walden: That's piping hot water, and they're warming up the bed. In the middle of the night if I need to use the restroom, then I have another bottle to use the restroom. This is a good strategy for both boys and girls. Boys and girls can do this. 

Dr. Universe: That's a smart strategy.

Von Walden: It's hard enough to get up in the middle of the night and get out of your bedding, let alone literally get mostly completely dressed. I cannot tell you how much work that is and how tiring it is to work at those conditions where your body really is working hard to keep warm, and it's just hard to do everything.

Von Walden: The hardest thing is to get up in the morning and get your cold weather gear on and pull your clothes and boots on. A lot of times, I'll bring in some of my clothes for, you know, 15 minutes and just warm them up using my body heat and the heat of my bed before I put them on.

Dr. Universe: Do you have to worry about animals at all? Like polar bears wandering through your camp or anything like that?

Von Walden: Yes. So, in the Antarctic, there are no polar bears, so there's no worry there. In the Arctic, there are polar bears, and I'm lucky enough that I've been able to see some. I was on an experiment in 2015 on an icebreaker where we were frozen into the sea ice of the Arctic Ocean, and the first night I was on the boat, a mother polar bear and her two cubs walked right by the ship.

Von Walden: And we were safe on the ship, but we were able to see her and her babies walk by, and she didn't pay us any attention. She just walked right by us, and the little babies were kinda tumbling. It was just beautiful. However, in Greenland, there have been sightings of polar bears. There's never been any problem with them harming any humans, but we do have to be careful of that.

Von Walden: These bears are in their natural environment. Absolutely incredible they can survive under these conditions, but they don't wanna mess with you. You're not what they're looking for to eat, normally.

Dr. Universe: When there's a group of scientists in the polar regions, and you're doing all of this hard work, and all of these important things, what do you do for fun when the workday is over?

Von Walden: Well, let me just back up and say our camp that we constructed last May was amazing. One of the things that we needed to do was generate power, and so we put together a whole renewable energy system. We put up 16 solar panels and four wind generators to drive our scientific equipment, and what we found was, because it's 24 hours of sunlight in May, we had way more power than we needed.

Von Walden: So, all day long when we're working outside, we would have the boombox going, and every day a new person from our crew—we had five people out there—would choose their own song list. So, we'd be cranking the music. In the evenings, before it got really cold, in our cook tent, we would just sit around and have a nice, long meal.

Von Walden: We had the best time. We laughed, we joked, we played games. One night, we walked outside and saw an incredible—It wasn't quite a sunset, but the sun was getting very low on the horizon, and so we all got our coats on and went out and just stood there, and looked at it. 

Von Walden: So, yeah, it's mostly work. When we get out there, we're up at 7:00 every day. And I'm telling you, by 8:30 or 9:00—because I'm an old person now—I was getting to bed to get plenty of sleep. I could hear the younger people playing games and having fun for another couple hours because they didn't need as much sleep. And, oh, another thing that we did every morning, we'd eat breakfast and we'd do yoga, which is kind of funny because I'm like the world's worst person at yoga, but it was a way of us just all doing something together to get us ready to work together as a unit during the day.

Dr. Universe: What's the best part of your job?

Von Walden: Oh, there's so many. I really do love the polar regions, and I love to travel to the polar regions. It's not for everyone, but I can stay pretty comfortable out there. I've been very, very fortunate to get these experiences. I love the science. I love learning about how the Earth works and improving our knowledge of the Earth.

Von Walden: Science builds upon itself, so I've been very fortunate to have very good mentors of my own, and to have worked with incredible graduate students and other colleagues who have really helped me along my scientific journey. And then I just feel like the education part of it, the fact that I've been able to come back to my university and teach about what I've learned, and teach basic things about the atmosphere and about remote sensing and about climate to my students, I feel like that's been a very good thing.

Von Walden: And then I also feel like, to some degree, I've led a life of service, where what I have done in my life has been really to increase knowledge for the world, and that's how science works. And it's one of the most gratifying things about being a scientist, is you leave a record behind of what you've learned for the next people who are coming on.

Dr. Universe: We talked a little bit about climate change. As somebody who is working right in that kind of area, do you think we're going to be able to solve it?

Von Walden: Oh, absolutely. I'm more optimistic than I have been in my entire career. I'm gonna stop, and I'm gonna first say, it is absolutely an issue. There's no scientific debate anymore. If you hear on the news that someone's debating the science of climate change, they have a different agenda that's not science.

Von Walden: If the climate system was not working the way we think it is working, we would have to throw out all sorts of major scientific discoveries—like how radiation propagates, how your cellphone works, how your microwave oven works. We would have to throw away a whole bunch of science. The science is settled. But I do wanna say that, as a person who studies the atmosphere, and even though I'm not a climatologist, I know a lot about climate change.

Von Walden: This is a serious issue for society to deal with. How we're gonna deal with it is still an open question. We are already dealing with it. We're undergoing a transition right now from using fossil fuels for energy to using renewable energies like solar and wind, and potentially even nuclear.

Von Walden: And so, we have the capacity to do this. And the fact that the energy transition really has started now around the world, and in our country, I can be very optimistic that we have the tools we need to solve this problem. The faster we do it, the fewer impacts future generations will have to endure.

Dr. Universe: That's so good to hear. I get a lot of questions from kids who are really afraid or really anxious and don't quite understand why we haven't solved it yet.

Von Walden: That's a really good point. I'd like to allay their fears a little bit and say that, when I was child growing up in rural Montana, we had fears of nuclear war because we were in what was called an arms race with the Soviet Union at the time. And in the news, you'd hear a lot of fearful things.

Von Walden: So, I understand that, and I understand their fears. There are a lot of questions about why we haven't done more, and that's a whole nother podcast. But I want to leave students with some optimism that the renewable energies are becoming cheaper than the fossil fuels, so people will do this just from a business point of view.

Von Walden: It's a non-polluting, cheap form of energy, solar especially and wind. You know, your listeners drive all across Washington and they see windmills. Those things are generating a ton of electricity, and it's happening. So, I'd love to leave people with some optimism. It's a big problem. It's an important problem. But the technology is there to solve it.

Dr. Universe: That's all for this episode, friends. Huge thanks to Von Walden of Washington State University. As always, if you've got a science question for me, you can submit it at askdruniverse.wsu.edu. That's A-S-K-D-R-U-N-I-V-E-R-S-E dot WSU dot EDU. Who knows where your questions will take us next?