 Hi again everybody. Welcome back if you've been with us and Welcome here if you're just now tuning in We're getting towards the end of our Super Science Saturday fun today But we have a couple more cool things to show you and this in particular This is a little bit of an atmospheric adventure story that you're gonna hear now and if you were with us earlier and if you watched the Hide and science you might have noticed a special tool that one of the scientists used to find the other ones it was a tool that measures carbon dioxide and Now you're gonna actually get to hear directly from that scientist Britt Stevens and he's gonna show a video and tell you a little bit more about that tool and how it's used and What it can tell us? As we go along as usual if you have any questions, we love questions So please enter them into the zoom chat or the Q&A and we'll have time to ask Britt some questions afterwards There you go, Britt. Tell us what we're gonna what we're gonna hear about Thanks, Tiffany. Thanks everyone for joining. My name is Britt Stevens I work in part of NCAR called the research aviation facility. You may have just seen a tour of The facility and I study carbon dioxide as scientists were interested in carbon dioxide or CO2 Because we want to know where it's coming from and where it's going to and one of the ways We try and figure that out is by flying those airplanes up and down And if if there's more CO2 near the ground, we know that something's emitting it and if there's less We know something's taking it up. So that's a really common Scientific approach, but it's pretty expensive flying those airplanes around and we had an idea of a way to do it For a lot less money, which is to bike a CO2 analyzer up and down the Mesa hill So we did that and we made a little video about it and that's what you're gonna see next And I'll be around for questions afterwards and you could type them into the chat during the show as well Go ahead and take it away, Tiffany Carbon dioxide is a gas. It's all around us. You can't see it. It's invisible and There's only a small amount of it in the air, but it's really important because it absorbs heat and right now It's making the planet warmer because it's increasing carbon dioxide is a carbon in two oxygens So it's written as CO2. So I usually just say CO2 for short It's invisible, but we've had instruments that can measure its concentration for about 70 years And in the late 50s Measurements were started at a place called Mauna Loa in Hawaii on the big island of Hawaii So what I'm going to do is draw a graph the numbers on the left are showing the concentration of CO2 in parts per million of CO2. So I'll write a big CO2 over here and then on the this axis over here is just the time or the date So these are years when those measurements were started In the late 50s the concentration of CO2 in the atmosphere was around 315 318 parts per million. So it was about right there and Dave Keely and the person who started these measurements found out after about a couple years that they were going up But they weren't going up in a straight line. They were kind of wiggling. So CO2 has been doing something like that ever since and it started going up even faster and By the time it got to Around 2000 it was in sort of the 380 390 range and then it crossed 400 right about 2016 and now we're right about 415 parts per million for the global average the reason that CO2 concentration is going up is because We're burning all these fossil fuels in our cars and power plants So those are fuels that were buried underground for millions of years. We've been measuring carbon dioxide Continuously at a place outside of Netherlands, Colorado called Nyawa Ridge. So this is at about 11,000 feet altitude We actually started those measurements in 2005 and if I plot those on here They are a lot noisier Then then the red curve and what they actually do is they go lower During the summer and they go higher during the winter and lower during the summer and higher during the winter We became interested to see what it was even closer to home So we installed an instrument here at the Mesa lab and that's been going since 2012 and What we found then was that CO2 was even more variable and it went from about The same place as the others, but it went all the way up to 650 parts per million Every you know every few days. There's a spike that goes way up and And the and the reason it's more variable Could be because they're people walking around the building, but it could also be because they're more cars and Until recently a coal burning power plant here in Boulder and other Sources of CO2 around the around the front range So one thing we've noticed is that in the middle of the morning There's often a spike in CO2 here at the Mesa lab And we've kind of wondered if that was because people were showing up to work late or driving around Boulder or if it's because The way the air mixes it just brings all the CO2 from down in Boulder to us So we're gonna try and do some vertical profiles by biking up and down the hill with the CO2 analyzer To During the morning transition period to get a better idea of what's causing CO2 at the Mesa lab to vary Okay, let's go get Tim to bike this CO2 analyzer up and down the hill a bunch of times So this is the bike CO2 analyzer Yeah, it's like other instruments that we have at field stations on airplanes, but it's smaller and battery-powered so It's like a big lunchbox. Yeah, I there's I don't think you want to eat what's in here And there's a little pump and I think I can turn it on here You can hear the pump running and that sucks air in to the instrument From a tube that is out on the front of the bike Yeah, and then the actual instrument I can take the lid off and we can look inside. It's a little bit easier to Tell what's going on If you can see in here, there's two tubes one going in and one coming out So that the pumps gonna suck the air in from outside and push it through these tubes and on one end of this gold colored So cylinder that's the word I'm looking for is a lamp So it's a little tiny almost like a light bulb that produces infrared radiation on the other side as a detector that Consents how much is there so if there's more CO2 in between here that would be less Infrared radiation making it the other end so so there's a signal we measure the voltage and the voltage would go down when the CO2 Goes up So but we basically just turn this on and turn the pump on and it'll measure continuously the whole time you're going We get a number every second And it also measures pressure At the same time and that's how we're gonna tell how high you are on the road Because sea level pressure is around 100 kilo Pascal's or 14.7 pounds per square inch up here It's about 80% of that because we're 5,000 feet above sea level so there's a lot less air above us And there's actually a lot less air above us here at the end car of Mesa lab Then there is down at the intersection of Broadway and table Mesa guys are pretty blue Yeah, there you go. We're all set just like that. There you are. Thank you 80.6 kilo Pascal says they start going down that that number will start going up some point on the way down that hill CO2 went way up. Maybe we should call Tim and find out where he is. Hey, Tim. Hey Where are you? 75 it was a pretty sharp transition right about where you are now. It looks like oh really Clearer. It's definitely colder here. We're getting the occasional uptick. I don't know maybe Okay, interesting went up to like 500 500 a Little bit noisier on the way up because those are the cars that went by and maybe a little bit of your breath But you can see the kind of a baseline I don't know this time if you go down there if it's gonna go higher Concentration of CO2 because there are more cars people are commuting to work or if it's gonna go lower because The sun's up and it's heated the ground and cause more mixing to happen. So We don't know. Yeah, let's do it again Okay, we're actually on table mason now a couple of cars are going by. Oh That's not you right there. Is it? You're at 419 now. There was you were 440 for about Two minutes on the way up there. So I don't think that was a truck. I think I was just a Puff of the dirty boulder air. You can see it's so peaceful out here An EV just went by full electric That was that was a gas burning car and the electric car didn't do anything But you know if you ignore the spikes from the cars the CO2 has been going down slowly as you've been climbing up bike number two was a success and I managed to convince Tim and Riva to do it one more time So curious what it's gonna look like this time coming back up which is what it is up here So I'd like this this slug of dirty air is moving up and like a layer Tim and Riva biked up and down the hill three times and now we're gonna check out What we measured what I'm showing here is a graph of carbon dioxide Concentration as a profile a vertical profile on the hill Pressure goes up as you go down and so the y-axis is a pressure and it's reverse So lower values are up and higher values are down so that that makes it a line with the real world So you can kind of think of this graph as representing the NCAR Mesa lab at the top left and then the intersection of Broadway and Table Mesa at the bottom right And then the x-axis is the carbon dioxide concentration So Concentration was almost constant Most of the way down the hill and then all of a sudden right as they got near the bottom It went shooting way up. So that's really cool I think this is a result of all the pollution that builds up overnight in in Boulder The air is usually pretty calm all of the burning of gas and cars and Burning of natural gas to heat homes produces CO2 that that accumulates overnight So let's see what we got when we Compare all the profiles we did and that's shown on this graph So again, this is pressure on the y-axis and carbon dioxide on the x-axis and the Mesa lab is at the top left And the Broadway Table Mesa intersection is at the bottom right. This is really cool So we didn't measure the same thing every time it changed a lot But I think it changed in ways that That we can understand so the the very first time down and up are the red and the orange line And they went they went way up to about four hundred sixty parts per million And on the way back up the orange line We saw some looks like little plumes of high CO2 On the way back up the very next time that Tim and Riva went down where the green lines here and Carbon dioxide was actually higher kind of on the hill on the way down But then when they got to the bottom of the hill it didn't the concentration didn't go up as much I think what that is is the air is starting to mix So it's the Sun is coming up and it's heating the surface and it's making that air Warmer and the warmer air wants to rise and sort sort slowly coming up the hill and then they did it one more time They were having so much fun. They wanted to go again at around 10 30 and those are the blue lines and Those are crazy. They They they saw really high CO2 concentrations on the way down the hill and then when they got to the bottom the Concentration was actually even lower than before So I think that they just happened to catch this big plume of dirty Boulder air that was Kind of wafting up the hill in the mid morning and that happens to be exactly the same time when we saw Some big spikes in the CO2 concentration in our measurements here at the Mesa lab And it's the same time when we usually see them So I think it's pretty clear that the spikes we see up here in the mid morning are a Result of all this air that's accumulated overnight down low getting sort of sucked up past the past the Mesa lab So now we know why we get these big spikes of CO2 up here at the Mesa lab In sort of the mid to late morning And that's great if we could only convince tim and riva to bike up and down the hill Three or four times every day. We could really do a great research project Well Hi, that was a cool adventure I was thinking watching that that you know, I wonder if we probably could convince Tim and riva to bike up and down that hill three or four times a day. It might not be that hard I think you're right You have to find somebody to do their regular jobs for them That's true That would be a pretty cool job. I mean brit your job is pretty cool from From measuring gases like CO2 and airplanes to going out and watching what happens when people are on bikes Your your work is a good adventure. It looks like Uh, well, it is nice to get out of the office and out from behind a computer screen every once in a while Yeah, the basic job is trying to figure out puzzles about The earth system. So I like that part too, even if it does involve sitting behind a computer No doubt about it. I have to know I mean, would there be any difference with tim if he's huffin and puffin I mean when we breathe out we exhale carbon dioxide, right? Would he be messing up those numbers at all? Yeah, that's we tried to put the tube way out front on the bike Like you could maybe see in the video. Uh, so that as the wind was rushing past That wouldn't happen and they were going downhill so fast that even if they went by a car The numbers didn't really spike but Tim and riva, um You know super athlete human athletes that though they are they they don't bike uphill as fast as they bike Downhill so on the way back up here. They were going slow enough that as the cars passed they got a big whiff of Exhaust and we might have seen their breath a few times, but I think it was mostly the cars That is pretty cool. It was so cool to get a real time view of that We do have a few questions that are coming in brit Um, some good questions violet is wondering who built the co2 detector well The box is something I put together, but the uh, the the sensor inside that you saw the electronic boards and the lamp and the detector is a is a commercial sensor Um, and then it just has a bunch of custom stuff around it. So The company that sells that um sells them to scientists And also people with commercial greenhouses who really care about the co2 and other industrial applications But uh, so the box um and uh all the pumps and the tubing and the battery and everything else I I kind of cobbled together The week before we were going to go ride Cool. Well, and it was funny because nicholas also said well if if you built that then Could you make a jet pack? And I wish Send me send me the instructions if you know how I'll give it a shot We'll work on that Um, there are a couple other questions in here. Uh, somebody's wondering what happened in the afternoon. All of this was done in the morning, right? Yeah, if you're watching really closely on that last graph We plotted some purple lines from the afternoon and that was that was a test run that I did the day before And when I got down I actually started at the bottom and rode up and then came down afterwards And down at the intersection of table mason and broadway that the co2 concentration was actually lower Than it was up here at the mesa lab And I think that's because of all the trees photosynthesizing and taking up co2 in the afternoon Oh, yeah, that would make sense Here's another one Um, aj is wondering why didn't the electric vehicle show up when the other cars appeared on the graph? That's an interesting piece, huh? Yeah, electric cars are really cool. The only the only thing they emit is water Or wait, no, I'm thinking of hydrogen cars backup rewind Electric cars don't emit anything The uh, you know the the electricity may have come from a cold burning power plant that emitted co2 far away But the um, but the cars it's driving is Is not emitting anything unless the people have their windows down and are Breathing hard. So just to clear up my mistake A hydrogen car, which is something else you can buy and um, it's good for the environment produces water But the cars that burn fossil fuels do it by taking the carbon and the fossil fuel and Combining it with oxygen to make co2 and so co2 comes out the tailpipe And it's interesting that you mentioned fossil fuels if anybody was with us for the fact or fib game earlier We were discussing the meaning of the term fossil fuels and actually people couldn't be fueled fueled I mean fooled about that No pun intended I voted for Jared's answer I know not entirely untrue. Yeah Oh, we've got some real science thinkers here this afternoon. We have another Question coming in asking would the number of plants or trees along the way affect the results or would it be about the same? I think they would uh, you know, we've done studies in forests in wisconsin and studied tropical forests and Measurements out in the middle of the ocean and and sort of the lusher and greener the trees are the more Rapidly they're taking up co2. So In the middle of the afternoon over wisconsin, you tend to see lower co2 concentrations just because the forest is denser and there's more sort of moisture for those trees out here the trees are spread out further and it doesn't go down Quite as much in the afternoon. We did a test with the we had tim bike right into the middle of a tree Up here. It was kind of windy We didn't see much so then we had him bike into the middle of uh, there's something up here called the ozone garden which is a bunch of plants that are sensitive to Ozone and we saw co2 go down by I think 10 or 20 parts per million in the middle of the clump of of plants Oh interesting. That's a that's a cool way to test that Well, and there's one more question This is this is a little bit related to sort of the plants and trees question Somebody's wondering, you know, we hear a lot about co2 carbon dioxide these days and global warming and climate change And somebody's asking does the co2 that we breathe out actually contribute to global warming? That's a great question Only if you had coal or oil for breakfast So it depends what you ate and the things people eat or tend to be either plants or animals that ate plants so the carbon that's in Cheerios that you have for breakfast came Um from a plant that grew quite recently probably within the last year Um and when it grew it took co2 out of the atmosphere and when you eat the Cheerios and you Add oxygen to that co2 and turn at oxygen to that carbon and turn it back into co2 and breathe it out You're completing a cycle and it's a cycle that happens really quickly So within a year the co2 goes out of the air into the plant into you and back out again Cycles like that have been going on for thousands of years and are Essentially in balance. So the concentration of co2 never Actually changes. It's only when we take something from out of this System, it's naturally in balance and add it. So we take Fossil fuels have been buried for millions of years and earn them we add them and that that has an effective change in the concentration so Although we can measure co2 from breath. It's not bad for the environment and There are actually ways to measure isotopes of co2 and tell the difference between co2 that's coming from fossil fuels or from people Okay, so as long as my breakfast is like all of chef Nancy's super science snacks with popcorn balls and marshmallows and And snow crisps and i'm good to go. I'm not My my my co2 isn't contributing, huh? Yep, exactly Okay, well, I don't see any other questions coming in and I will say it's just about time to get ready for our grand finale if anyone has joined us In previous years for super science saturday, you know that the annual ping pong ball launch Is always the big event at the end of our day So brit, I know you want to get out there and watch that So, uh, everyone's getting set up and we'll say goodbye to you and thanks so much for for sharing your experiment And your information everyone for joining. Um, that was a lot of fun Thanks so much and we will see everyone in a few minutes for the final event of super science saturday