 All right, everyone. Welcome to Meet the Experts, Ocean Sniffing Airplanes and Climate Science around Antarctica. We are so excited to welcome you all of you today to Meet the Experts. I'm Katie Wilson with the UCAR Center for Science Education, and we love having all of you join us for Meet the Experts. This is a bi-weekly program where we get to meet experts from the National Center for Atmospheric Research, and we get to talk to different experts every other week. There's really amazing jobs here at the National Center for Atmospheric Research. You can be a scientist, a pilot, a mechanic, a computer scientist, a chef, an educator. You can work in augmented reality with supercomputers. There's so many different careers that you can follow here, and we are so lucky that we get to talk to all of you today and hear your questions and connect you with different experts from the National Center for Atmospheric Research. A few housekeeping things before we get started. I'm going to ask everybody to keep your cameras off and your microphones muted for now just to avoid distractions. If you need any help at all, please type in the chat. Tim and I are here on standby to help you out. If you need any help, there is closed captioning available that you can toggle on and off in Zoom for you, so feel free to use that if you like. Throughout the program, you might have questions based on what you see and what you hear. Maybe Britt is going to say something that makes you wonder something. We would love to hear your questions, so please type those questions in the chat throughout the program. We'll also have a time at the end for questions as well, but feel free to type questions about things you wonder before as well as anything you see and hear during the program today. We can't wait to hear your questions, so thank you so much everyone for joining us. Without further ado, I'm going to hand it over to our expert. Today we are talking to Britt Stevens, who is a senior scientist with the Earth Observing Laboratory at the National Center for Atmospheric Research. He studies the global carbon cycle and uses airplanes to do that. Britt, can you tell us a little bit more about why you study carbon cycles? Sure. Thanks, Katie. Thanks everyone for being here. I'm going to share my screen and give a little PowerPoint presentation and then we can just have questions or discussions afterwards. Can you see my first slide? Sure can. I just wanted to start by explaining why carbon dioxide is interesting and what it actually is. Carbon dioxide is a gas in the atmosphere and we abbreviate that CO2. There's not a lot of it. This graph shows values between 300 and 400 parts per million. This is a famous curve called the Keeling Curve, which runs from the late 1950s to about 2010. CO2 is going up in the atmosphere and that's a big concern because even though there's not much of it, it's responsible for keeping the earth the temperature it is. Because it absorbs heat when the concentration goes up, we absorb more heat and that's causing global warming. One interesting fact is that we would have expected CO2 to go up almost twice as fast if everything that we emitted from cars and power plants stayed in the atmosphere. That's shown by the yellow line here. The difference is a result of the world's oceans and forests taking up more carbon dioxide every year than they used to previously. They're taking up about half of what we emit, which is great. Things would be a lot worse if they didn't, but we don't understand why they're doing that or how the processes actually work well enough to say if it'll continue in the future. That's really why we want to study carbon dioxide in the atmosphere and my job is really trying to figure out where all the CO2 we emit ends up, whether it's the forest or the ocean and why. But first I wanted to go back and tell you a little bit more about how I got to where I am today. I grew up in a small town in northeastern Oregon shown by this red star and it was a great place to grow up because we had really high mountains and these really deep canyons and lots of great places for doing things in the outdoors, exploring nature. I was always outside and developed a real appreciation for nature and a real strong curiosity about how the natural world worked. I also had a great earth sciences teacher in high school who would take us out on backpacking trips and river rafting trips and teach us all about the geology of the area. So when I got to college I ended up studying earth sciences and actually took some atmospheric chemistry classes in college as well. It wasn't until actually about a year after college that I finally decided that I wanted to go to grad school and wanted to pursue this as a career and I always thought it took me that long to decide but it turns out I had an inkling a little bit sooner. I found this recently at home which is something I wrote for a school assignment when I was seven and it says when I grow up I want to fly an airplane or be a sports player or a scientist and when I have time I'll probably rest and I'd live in LA. So I'm not a sports player and I don't live in LA but two out of four isn't isn't too bad. So after college I got a job as a research assistant for the US Geological Survey and this picture on the top left is of me in northern Manitoba helping out in a project measuring how much carbon dioxide was coming out of soils during winter. So you can see a little white bucket on the back of this eight-wheeled vehicle and we would go set that down in different places and measure how fast the carbon dioxide went up inside the little bucket but the fun part was driving this truck around and that experience and a number of other sort of field projects I went on made me realize I could study something I was interested in but still get to do fund things outside so at that point I was hooked and I decided to go back to graduate school and I went to a school called the Scripps Institution of Oceanography which is in San Diego California and what I really like to do was to build things and so what I did for my graduate project was to build an instrument and that's shown in the bottom picture here that measures oxygen and carbon dioxide in the atmosphere so about 21 percent of the atmosphere is oxygen and that's what we breathe and if we measure it at the same time as CO2 you can actually tell a lot about what's affecting CO2 so I built this instrument and took it out on some ships the picture on the right is about a thousand miles from land out in the middle of the Pacific Ocean where I was measuring oxygen and CO2 in the air but I got to help out servicing some of the instruments that are out on buoys and and so I got to continue doing doing fun things outside while I was in graduate school once I graduated I came to Boulder Colorado and then got a job for NCAR and my graduate degree is in oceanography and when I tell people that they always they always ask me what the heck an oceanographer is doing in Colorado and don't I know that the ocean is actually not you know anywhere near here but I study the atmosphere and you can do that anywhere and I actually also study the forest so this picture on the left is a place called Nywat Ridge which is just up the mountains here from Boulder where I deployed some instruments to measure carbon dioxide in the air and I'm staring at them trying to figure out probably why they're not working also after starting working here I got started to get involved in doing research from aircraft so the top right picture is one of the first aircraft projects I've worked on it was called Cobra there's a very important and atmospheric research to have a catchy acronym for your field project so this one was flying around in a sort of a small jet called a Citation II and the thing I'm touching is a glass flask we were using those to collect air and bring it back into the laboratory to do measurements on measurements on that air and the bottom picture is me on the NCAR C-130 aircraft which is a really large cargo military cargo plane and the instrument I'm behind is actually that same instrument I took out on the ship but now I'm trying to modify it to work on an airplane because it's a lot better if you can make the measurements while you're flying along and not have to bring that air back to a lab but this instrument still sort of looks like the kind of thing you put together in your garage on a weekend it's not it wasn't really well built at that point but another great thing about working at NCAR is that there are some wonderful engineers here and I was able to team up with some engineers and rebuild this instrument from scratch so this is a picture of what it looks like now and the picture on the picture on the left is of the whole rack that bolts to the floor of the airplane the picture on the right is of the sort of the inside of it and the way it works is the way it measures oxygen is that it has a lamp with a tiny amount of xenon in it and it's just like the fluorescent lights in the ceiling maybe of your classroom that glows when you put energy into it but it emits a particular wavelength of light that's absorbed by oxygen and then there's a detector and we just use pumps to pull air in from outside the airplane and push it past this lamp and we measure how much of the light is absorbed in that air so if the light is just a little bit dimmer we know there's more oxygen in the air that's in between the lamp and the detector and vice versa so so why go to all this trouble to measure oxygen and carbon dioxide from aircraft I'll now switch over to just say a bit more about the sort of science questions we're trying to get at this is a schematic of what's called the global carbon budget it's just sort of like your bank account but for the carbon dioxide in the atmosphere and on the left are the sources so every year we're emitting almost 35 it's billion tons that's what that gt stands for gigatons if you know your units so 35 billion tons of carbon dioxide every year from making electricity and power plants or driving cars or other industrial processes and then about six billion tons from just cutting down forests primarily in the amazon and burning those trees and as I mentioned about half of that stays in the atmosphere and that's what's causing CO2 to go up every year but almost 30 percent we believe is taken up by forests and about 25 percent or so the 23 percent is taken up by the oceans and one of the key ways we know these two numbers is actually for measuring oxygen because when the forests take ups that CO2 they do it through photosynthesis and they produce oxygen while we do that so so oxygen has already helped get these numbers but the the catch is we don't we still don't really know why say for example the ocean is taking up that much and where we think that about half of this amount that's been taken up by the ocean every year is taken up around Antarctica and the next slide I have says a little bit more about why that is so the ocean around Antarctica we call the southern ocean and it goes all the way around and because the winds also can blow all the way around they never run into any land they can push really hard on the water and the currents that they produce end up bringing water up from below they sort of blow the water away at the surface this is a cross section with what would be the south pole on the left and heading to the north on the right of the currents inside the ocean so because the deep water comes up around Antarctica and it's been it's been deep for hundreds to maybe a thousand years it's never seen the impact of humans burning fossil fuels so it comes up and all of a sudden sees this atmosphere with a lot more CO2 in it and it absorbs a lot of CO2 so that's why there's a big sink there and it's really important for the climate system but it's a really complicated area because of all of the different processes that are going on so when that water comes up it warms it's cold down deep and then it starts to flow south and the sun shines on it warms it up and if you warm up water it actually the gases in it become less soluble and they want to sort of bubble out if you leave a soda can out in the sun on a hot day and open it it'll actually have a lot more pressure than uh than if it was just out of your out of your refrigerator and the the opposite of that is that when you cool the water sometimes these waters go over towards Antarctica and then cool off and sink you actually absorb both oxygen and carbon dioxide but if you have a bunch of algae that are just doing photosynthesis in the surface water they actually do do the opposite with oxygen and CO2 so they produce oxygen and they take up carbon dioxide just like a plant in your in your garden or in your house so if we measure oxygen and CO2 and they go in opposite directions we know that biology is what's affecting CO2 and if they go in the same direction we know it's the heating and cooling so that's why we've wanted to measure oxygen and carbon dioxide over the southern ocean for a long time but it's hard to do because the southern ocean is so far from anywhere that people live it's hard to get to and it's also a very harsh environment so we had a project where we were measuring from a ship and this is a picture of the ship in the top left it's called the Lawrence M. Gould and it goes back and forth between Chile and Antarctica almost every month to resupply people who are doing research on Antarctica but we were measuring from the ship the instrument is shown on the left here and if you look in this picture in the bottom right there's a tiny white thing on this black mast which is the inlet where we were sucking in our air and we were putting that up there and the captain was laughing and making bets with his crew about how long it was going to stay up there and we didn't really appreciate you know why they were doing that but then a year or so later I saw this nice documentary put out by Rutgers University I'm just going to show you what the first 10 seconds of the trailer and see if you can see that little white inlet here it's it goes really quickly but this just gives you an idea there it is right there of what the conditions are like if you're going back and forth in a ship over over the southern ocean and it can be quite you know unpleasant for people so we finally realized that a better way to do this was to fly an airplane and so we came up with the idea for a study which is called ORCA as I mentioned it's important to have a catchy acronym this one stands for O2-N2 ratio and CO2 airborne southern ocean study we actually report the oxygen concentrations as a ratio to nitrogen but really it's just so we could get the O and ORCA's there this is a picture of the airplane flying over some icebergs near the Antarctic peninsula and in the bottom is a map from Google Earth what's shown is a satellite picture of chlorophyll which is essentially how much algae there is photosynthesizing at the time of the project and then the different colored lines are all of the flight tracks from where we flew so we typically would we were based in Punta Arenas, Chile and this was during January and February of 2016 and January and February is summer in the southern hemisphere so so all of the algae was growing and it was and the sun was heating the surface so we would typically fly at high altitude over to the Antarctic Peninsula and then descend down and we would do a series of what we called porpoise maneuvers where we would go up and down out of the atmospheric boundary layer so that portion of the atmosphere that's actually turbulently mixing with turbulence and can actually pick up gases from the ocean surface so the last thing I wanted to show you was a oops sorry I forgot one extra slide to just tell you a little bit more about the Gulf Stream 5 jet which is based here at NCAR if you're local in the area and they have an air show at the Rocky Mountain Metropolitan Airport sometimes we roll it out for people to look at but you can tell by looking that it's not a typical airplane it has all these extra probes sticking out the top and bottom of it and things hanging off the wing and those are all scientific instruments or inlets for sucking air into them and the picture on the bottom right is what it looks like inside during a typical campaign it's there are very few seats it's mostly all instruments so it's a flying laboratory and it's it's kind of like you're flying inside the instrument when the plane gets down into the boundary layer you can feel it bouncing around so you know you're in air that's that's turbulent and is is is connected to the surface and all of a sudden you see the gas concentrations change and sort of know instantly what's what's going on so to give you a little bit more of an idea what that's like I have a video from one particular flight during orcas it was an eight-hour flight but it's sped up here and the left will be a picture out the front of the plane and the top right is a map of where the plane is so it'll you'll see a red line and it's starting here in Pundarenas and the bottom right is the graph there's a going to be a gray line showing the altitude on this left axis and then a red line showing oxygen on this right axis and a blue line showing carbon dioxide or CO2 on the right as well so just just remember that oxygen is red and CO2 is blue on this graph so I'll go ahead and start playing it here we go we're taking off from Pundarenas and we got a little bit of ice on the front of the camera going through those wet clouds but as you see it slowly sublimates away which that happens a lot when you're in a commercial airliner and we climb up out of Pundarenas and then kind of do a little up and down maneuver where we're going in and out of the stratosphere which is sort of isolated from from the surface and has different gas concentrations it looks like we're in outer space on the camera unfortunately in real life it's not quite as that dramatic your eye adjusts and it doesn't look like the blackness of space but I wanted to pause it real quick so we're about two and a half hours in and we've just gone across Drake Passage I showed you that other video and I've been across Drake Passage on a ship and I can tell you this is definitely the way to do it on an airplane you get plus you get to go home and have a nice warm meal and sleep on a bed that's not moving around and we're starting to descend and you can see a lot of structure in the little lines for oxygen and CO2 that's a result of going in and out of the stratosphere but before we go into the boundary layer I wanted to ask people to think about what they what what you think oxygen and CO2 are going to do so we're about to go down really low over the water during summer off of Antarctica do you think both oxygen and CO2 will go up because the sun is heating the water and making them come out do you think both oxygen and CO2 will go down because the water is cooling off before sinking or do you think oxygen will go up and CO2 will go down because of all the algae photosynthesis so I if you want to type into chat both up both down or oxygen up or you can say O2 up CO2 down I'll just give a few I'll just give a minute for people to sort of think about what what might happen and and I'll just share that at this point we didn't know what was going to happen either that's why we took this airplane down there we had somebody on the science team who thought we weren't going to see any changes in carbon dioxide at all and was sort of willing to bet that we weren't because of some computer model runs we had that said said that we wouldn't but I'll go ahead and play it here now that you've had time before before you play it we do we have some responses oh yeah let's just got them you know one person said goes up another person said CO2 up and O2 down and then third person says O2 up all right those are all good guesses so watch the red is oxygen and and you'll see as we get low here oxygen goes way up and then this blue CO2 trace goes down so here we are flying around in the air that's feeling the surface and we have really high oxygen concentrations and really low CO2 concentrations and we're looking out the window to see if we can see any seals or penguins and now we're doing these porpoise maneuvers that I mentioned where we go in and out of the boundary layer sort of above and below the clouds and we're going to do that about five times and of course that all happens much more slowly in real life it's fun to see this this fast and so what you'll notice if you look at the red and blue lines and the gray line is every time the plane went up and down CO2 went up and down and oxygen went up and down and they're always going in opposite directions so when we're down low like well this one we didn't get out of the clouds just barely can see the water there see oxygen was high again and as we're coming up oxygen goes low and then we do one more one more low porpoise and then we're going to do a series of sort of higher profiles maybe 20 000 feet on the way back to Punta Reina so it takes about about two minutes for the video to play I'll just let it go if anyone has any questions they wanted to ask now I'd be happy to answer them and I also have a summary at the end yeah so we have a question from Amy's group asking so when you're showing us when you're in the sky and it looked like you were in space do you ever travel at night if you can and if you do can you see the stars really well oh that's a great question we do these flights at night sometimes and I don't I don't remember seeing great stars from the plane I think that's because just the lights inside the plane always make it so your eyes aren't really adjusted well but you do see that you see the moon sometimes I with this great experience flying out of Anchorage sort of to the north pole and back where the the moon was directly in front of the nose of the airplane full moon so you could sit all the way in the back of the airplane look down the aisle and you could see the moon right out the cockpit window of the airplane yeah so so yeah I think if you turn all the lights off inside maybe you could you could see the stars that's amazing we have another question here asking so in your job do you get to travel to other states to see how much co2 is in other states or which state has the most co2 yeah that's a great question for the united states the highest concentrations are on the eastern seaboard where there's so many more people and cities and cars and power plants but we've done measurements around the rocky mountains in the in the you know the last we measured in Utah and Arizona and Colorado here we are coming into land you can see the landing gear just came down and for that study we were trying to figure out how much co2 the forest were taking up and measuring really small differences between between those states during summer there's a lot more photosynthesis in the in the in the forest on the eastern part of the country so you get co2 kind of goes down as the wind blows across and then if you're right downwind of New York City or or Boston it would be quite high I just wanted to show one other thing here now that we've landed in winter anus which is this little cartoon again just highlighting that for these big profiles we did on the way back every time the plane was down low where this see the gray is down near the surface oxygen was high and co2 was low so because they went in opposite directions we knew that biology the algae in the surface was what was dominating the co2 exchange at that time so that was something we didn't know before and now we're working on incorporating that into computer models that are trying to predict what the system is going to do in the future and I'm happy to take more questions wonderful thank you so much for it students feel free to type if you have more questions in the chat we would love to hear from you oh we have one from Ms. Gomez's class and who I believe is in California asking when you're on a plane do you ever feel the plane moving I've never been on a plane but how does it feel moving oh wow that's a great question you do feel it moving when when you're really high and the air is really smooth sometimes you don't feel it moving at all and you could you could almost forget you were in an airplane but when the plane's down near the surface it bounces around quite a bit and for these types of studies where we're only down near the surface for a few minutes most people you know do just fine it's like kind of being on a bumpy roller coaster for two or three minutes and then you go back up where the air is smooth but we've done studies where we fly around the mountains and then it's bouncy the whole the whole eight hours or I was on a project with the C-130 where we were flying over down low over the ocean for eight hours and unfortunately some people's stomachs don't really like that kind of thing so but that doesn't keep them from being atmospheric scientists so so it's kind of luck of the draw whether you have have a tough stomach or not oh man not for not for the people to get plain sight very much right we have a question from one for homeschool groups asking what is behind you right now oh yeah well that instrument I showed you a picture of in one of my slides is right is right there it's open because we're working on improving it before the next project that's one of the that's one of the lamps that goes inside of it the thing behind me on the right is that hard to see but that's another instrument rack that's going to go in these C-130 planes that have skis on them that go back and forth to Antarctica to resupply McMurdo station which is south of New Zealand and so it's just going to ride along and do measurements while they're resupplying resupplying the stations that back there you see a bunch of aluminum gas bottles we have to calibrate our measurements against air that we know isn't changing so we do that with these it's like a giant scuba tank and then there's something right behind me that we call the big blue box so very descriptive but that's it's like a wine rack for those cylinders we have to keep them insulated and on their sides so that the gases don't separate good question our california students like the big blue box name i got a big lol in the chat we have another question from one of our colorado school groups asking what does it mean by ocean snipping planes when it looks like you're in the sky yeah well we're not sniffing the water exactly but the air just above the water so yeah if we stick the little tubes outside the plane and we have a pump that's sucking air in so i think of it like flying along sort of sniffing with your nose if we could we would fly 10 feet you know two feet above the water and sniff as close as we could but for safety reasons we can only get down to about 500 feet um but the instruments are sensitive enough that we get a pretty good you get a pretty good whiff of the gases either coming off the ocean or going in so britt would it be fair to say that pretty much everything in the in the air that you're flying through probably came out of the ocean and not very much if it came from somewhere else around in article all of the changes we're seeing are from from the ocean if you fly around here the hard part is separating how much is the forest and how much was a car and how much was um the ocean you know before it got onto the continent um there's when ncar opens back up there's a public um exhibit uh and there's a co2 instrument on the roof of the mace lab at ncar and so people who are local can go see what the co2 concentrations like around here but those changes i was showing you were only one or two parts per million co2 around here every night it goes up by about a hundred parts per million just because cars and burning things and to heat our homes um has that much larger effect oh okay we'll do we'll just go another minute just to see if anyone has any final questions in the meantime i have a question for you britt um we think you are a science superhero with all the research that you're doing and we are curious if you what would you consider your science superpower to be that lets you do your job um that's a tough question i you know i've always like taking taking things apart and trying to put them back together um uh you know electrical or mechanical type type things you know if you know what a vcr is i can remember taking one of those back in the day but um you know anything that breaks but you know when you do that you tend to break things a lot and so i you know i guess in the world of building instruments and flying them on airplanes i i take pride in my ability to um know when an instrument's broken and know what's wrong with it and be able to fix it sometimes that happens you know right before takeoff when everybody else is you know ready to go and your instrument's broken and it's a really high pressure situation and you have to get to quickly figure out what's wrong and and come up with a fix with it so that everybody else can go take off and and do the research flight so um and and i and i find it fun doing that too that's awesome awesome so sometimes in science you got it's good to break things so you know how to fix them later that's good so if you break things students you just say i'm working on it i'm a scientist in training all right we have another question in the chat um oh a couple more questions great um have you had any really rough weather situations for it uh you know our our pilots do n car has four professional pilots and they do a really good job of monitoring the weather and and keeping us out of trouble the the scientists always you know we do measurements for the types of things i study where we're just sucking in air but we also do measurements for people who want to study severe weather or clouds or thunderstorms and so we often have the situation where the scientists want to fly right through the middle of a thunderstorm because that's the part they don't understand very well because they haven't nobody else has done that before and so um there's always this uh you know a lot of teamwork to figure out how how closely that can be done uh safely um i haven't been on many of those projects because they're not as you know the flying is not as you know as pleasant with all that bouncing around we were flying uh really high once over a thunderstorm and the the airplane did a um you know hit a updraft and then a downdraft and and and people who weren't um seat belted in kind of um got bounced around but uh i you know i talked to the pilots afterwards and they said that the you know the airplanes are designed to hold much worse than that it's really just the people that they have to worry about um bouncing around so so luckily i haven't been in anything too rough on our plans great question all right we have another one from california saying now that the covid-19 pandemic has happened is it hard for you guys to travel or fix things or anything like that yeah that's been a that's been a real challenge uh for what ncar does in supporting um field campaigns on these aircraft a lot of that has had to be delayed um first projects were delayed a year now they're being mostly delayed another year we had a there's a big project planned based out of south korea to study the atmospheric chemistry that happens when all of these thunderstorms over asia lift this air really high into the atmosphere that's been delayed a couple times because of the travel restrictions other people have instruments that are out in the field that break down and that's been hard to travel to get to to fix the the whole Antarctic program that the united states national science foundation runs was pretty much put on hold last year and they're only doing sort of part of what they would like to do this coming year so pretty much everything's just been delayed but i will say other people are learning a lot about how the atmosphere works because we did kind of this experiment where people didn't drive or fly for a couple months so there's been a lot of interesting scientific results to come out of that wonderful well it looks like that is all our questions we have in the chat for right now so thank you so so much brit for sharing a little bit about what you do um and taking us behind the scenes in your lab a little bit there that was really fun i know i definitely learned a lot i hope our students today learned a lot too thank you so much for taking the time we want to i want to remind all of our students that this is a bi-weekly program through the end of may so we do have another program coming up in two weeks you can join us in two weeks on april 29th we're going to be talking about testing the limits of weather predictability with falco jute so it's going to be 11 am on april 29th so we hope that we will see you there again in the meantime feel free to say goodbye in the chat we loved having you there we'll have this recording as well as past recordings of all of our other meat the experts available on our website so feel free to check that out and thank you so much brit um we had a lot of fun today yeah well thank you and thanks everyone for joining awesome thanks everybody we'll see you next time