Solving air chemistry puzzles from the sky

[music] Whether you are here or joining us virtually, thank you for sharing your time with us today for this NSF Encar Explorer Series lecture, solving air chemistry puzzles from the sky. with um Eric Aole uh Teresa Campos and Alisandro uh Franken. I am Elizabeth Maize and I am part of the education engagement and early career development or EDC team that shares the National Science Foundation National Center for Atmospheric Research [music] and the worldclass research that we do here through the explorer series. Uh NSF ENCAR is a US um sorry is a worldleading organization dedicated to the understanding of Earth system science including our atmosphere, weather, and the sun and the importance of all of these systems in building national resilience and protecting communities. So for tonight's event, you'll be able to ask Eric, Teresa, and Ali questions after their presentation. If you are in person, you can raise your hand and I will come to you with the microphone and um we will have a our speaker our speakers will sit in a panel over here. If you're joining us virtually, you can ask your questions using the Slido platform. So, if you scroll to the bottom of the web page that you're watching this on, you can see the Slido window just below. And if you haven't already, go ahead and click on the green join event button and you can ask questions on the Q&A tab. So our speakers also have a few questions for us. So for both our inperson and virtual audience, you can respond on Slido. So, if you're in person, you can use your phone or laptop to na navigate to the slido.com and enter the codeexplorer series or scan the QR code. And just a reminder, this event is being recorded and will be available on the explorer series website. And with that, I would like to formally introduce our three speakers. So each of our speakers is a scientist within the NSF ENCAR atmospheric chemistry observations and modeling laboratory or ACOM. Dr. Apal Eric Ael is a is the head of the experimental science section and brings more than 345 years of experience studying atmospheric chemistry. His work focuses on measuring trace gases and understanding their roles in air pollution, hazardous air pollutants, and wildfire smoke. Eric is a leader in research to understand the role of volatile organic chemicals in our atmosphere. Dr. Terresa Compost also works within the NSF Encar Earth Observing Laboratory as well as ACOM and has spent 35 years leading airborne measurements of key atmospheric gases including carbon dioxide, methane, ozone, and water vapor. And her research has contributed significantly to our understanding of the carbon cycle and atmospheric composition through field cam campaigns around the world. Dr. Dr. Allesandre Francin has over 15 years of experience in experimental atmospheric science and his research focuses on airborne and field measurements of reactive gases and aerosols advancing our understanding of ozone chemistry, aerosol formation and atmospheric processes. His work illuminates many of the complex interactions between these gases and aerosols. together with their expertise. Together their expertise spans atmosphere chemistry, air quality, and advanced observational techniques providing a unique perspective on the science of Earth's atmosphere, which we will hear more from them shortly. But first, we want to hear from you all as to what you think of when you hear the term air pollution. So, let's go to that word cloud. Take it in. We have smog. Wow, that's really a lot of people must have thought that. And then a lot of other variety of ideas. So, um I will hand over the mic and get your response or reaction to that world uh word cloud. >> Here we go. Thank you so much for the introduction. Thank you all for coming here tonight. It's nice to see you guys. And uh thanks for everybody online who's uh tuning in to listen to the talk. So Theresa Eric and I are scientists at ACOM. AOM stands for atmospheric chemistry and observation and modeling and it's a laboratory that combines groundbased measurements, lab experiments, and atmospheric model to to study air chemistry in the atmosphere. All right. Climb. Climb. Now, descend. Descend. This is the robotic voice that I heard in my headset while we were taking off uh from a US air base in South Korea. And my colleague turns to me uh on the across the aisle and asked me, "Is this normal?" No, that wasn't normal. Uh we learned only the full story after landing after sampling for eight hours as at 40,000 ft that a distracted fighter jet pilot was in a collision course with our heavy and relatively slow research aircraft. But luckily our uh very good pilots took care of the situation and avoided a collision. No big deal. Uh, another another time I found myself in a pool in an FAA facility uh, in Oklahoma strapped on a mocked air aircraft seat upside down in a cage. And that was I was um inside uh a a training program for um, learning how to escape a plane that land crashes on the water. Uh, another time, uh, I was, uh, in Guam near the runway on the tarmac with a pillowcase that I might or might have not borrowed from the hotel full of a huge chunk of dry ice, smashing it on the ground to try to get it into smaller pieces to fit my instrument that requires dry ice in order to cool down the photo multipliers. So I wouldn't say that our job is dangerous but it can definitely be exciting. Uh can be a little tedious too because before all these measurement campaign intensive periods we spend weeks in the lab testing at nauseium our instruments to make sure that they're going to perform well during the measurement campaign. And after the measurement campaign, we spend a ton of time in front of the computer looking at data, making sure that they're quality controlled and doing data analysis to try to find something interesting, a new discovery in them. But you know uh tedious or exciting. We believe that our job is important and we are willing to go to great length lengths to uh ensure that we collect a lot of high quality data because we know that the more data we get, the more chance we have for a discovery. And more discoveries mean deeper understanding on how gases and particles interact with each other affecting our health and the atmosphere of our planet. So in this talk we're going to talk about air chemistry. what it is, why we studied, how we studied, a couple of example of of things we learned while we studying it and what challenges and some of the challenges that remain. All right. So, what do we mean with air chemistry? Air chemistry is the study of the molecules and aerosol that interact in the air in the sky. And studying it is important because we can predict for example uh when smoggy days are going to appear and sometimes even trace back the pollution to its source like we see on this image here from a waka model that shows how um Canadian fires last last summer affected the northern uh or northern east of the US. By understanding air chemistry, we can effectively fight air pollution and we'll see some of the examples uh later on. We also can study by studying air chemistry, we can also um understand stuff like the thinning of the ozone layer and what causes it and provide viable solution to fixing that problem. So why would we care about air pollution? Well, air pollution affects um our health. Uh 99% of the world population lives in places that are somewhat polluted and uh um outdoor pollution uh is estimated to cause millions of premature deaths worldwide per year. It also causes environmental impacts. For example, interferes with plant productivity. Uh so affects the food chain. Um, also of course, uh, greenhouse gases, uh, lead to warmer temperature that change habitats for animals that need to adapt really fast, and if they don't do it, simply, um, die off. So, let's see uh, what you guys answered. I think I can have maybe the answers of the question. So, what fraction of the air we breathe do you think we are studying? All of it, [clears throat] half of it, 10% or a teeny tiny amount, like what? Way less than 1%. Let's see. Yes, somebody knows here. Way less than 1%. They are the winner. Uh, let's go back to presentation. Let's go back to the presentation. Yes, that's way less than 10%. If you, as many of you here probably know, the air is composed mostly of nitrogen, which is in Earth, and um we don't care about that. Uh of oxygen, we do care about that, but we don't study that that much. It's super important because it allows us to breathe and allows uh life on Earth. But what we're really interested in is down here. And if we we don't have a slice because if we would make a slice in here, it would be invisible. In fact, we uh we measure the the components of the atmosphere um that we're interested on in ppm, part per million, ppb, part per billion, and ppt part per trillion. Part per million is like finding a specific person inside the population of Denver. Part per billion is like finding a handful of people within the population of Earth and PPT is like finding a foot of a person inside the population of the earth. They're really tiny amounts but they're very important. uh the sources of pollution uh can be primary which means that they're directly pumped inside the atmosphere and um those primary uh pollutants here there are some uh like NO2 nitrogen dioxide sulfur dioxide particles VOCC's carbon monoxide and those can be uh generated by human activity like exhaust of cars and trucks factories but also natural activity wildfires volcanoes lightening even uh there are of course if there are primary pollutants there must be also secondary pollutants and those make up the bulk of the air chemistry we study. We are really interested in those and for us um they are particularly interested because they're tricky to predict where they're going to be, how much they're going to be and they have a really substantial health implications like ozone and particulate matter are secondary pollutants for example some of the particulate matter secondary. So ozone is a a prime example of secondary pollutants and uh we need three ingredients to make ozone. Sunlight, NOx and VOCC's. NOX is a shortand for the combination of nitrogen oxide N and nitrogen dioxide NO2. And those are emitting usually by burning things at high temperatures like engines, factories, power plants. they can be emitted by lightning too. Uh VOCC's uh stand for volatile organic compounds and those are chemicals that are organic which means that they contain carbon and hydrogen and volatile means that they evaporate easily so they get into the atmosphere relatively easily. O also ozone is interesting because we can have good ozone and bad ozone and sometimes this can be confusing. Uh, good ozone is located in the stratosphere and that's important because it's protecting us for damaging UV radiation. So, it's about 12 miles up and it's awesome to have it up there. But, uh, there is bad ozone uh, which is located in the lower troposphere where we live and breathe. And that's bad because it's a very powerful oxidant that damages lungs and plants. I always think of it like a toilet brush that is great to have next to your toilets, but it's pretty bad to have it on the counter of your kitchen for example. Uh so something really cool that I don't think that uh people appreciate enough is that pollution has been decreasing uh since the 70s and there are a ton of success story about decreasing pollution uh and that's been thank thanks to the successful implementation of legislation that regulated emissions. In fact, we don't hear anymore about acid rains because SO2 has been decreasing dramatically from uh filtering out at the source. We don't we don't hear too much about ozone hole because uh all the refrigerant have been changed into stuff that doesn't harm the ozone. We don't hear anymore about lead poisoning from breathing air because all the all the gasoline has been changed in unled. Of course, there are still issues like CO2 is still increasing. New pollutants are coming up like those PAS those forever chemicals, but in general um stuff a lot of stuff has been going down. Here is an example of PM2 PM2.5 aerosols from 2000 to 2016. And it's really cool to see how dramatic the difference is. And we can say the same for almost any of the primary pollutants SO2. This is NO2 for example. And this is a movie that goes from 2007 to 220ish. And you can see everything decreases. Now it's like New York and Los Angeles left and they're decreasing as well. Uh so and this has been also reflected and and maybe the fact that we don't appreciate enough is because while those pollutants are decreasing the EPA also tightens the limits of for for these pollutants. Here is an example of a NX which is a national ambient air quality standard for ozone. They started out kind of optimistic. Then they realized let's put it at 120 ppb in 79. But then after that uh they've been decreasing it fairly steadily until until 2020. And those are the current um we we're sort of plateaued now a little bit. Uh and those are still the current uh limits. Of course we're still far from an ideal situation. So around 40 50 ppb where it would be kind of uh background but uh yeah there's been progress and um similarly PM 2.5 uh limits have been decreasing as well. All right now I'm going to switch out to Teresa. Hi, I'm going to talk about the tools that we use to uh quantify the composition of the air. Um, and I'm first want to compare the different platforms and the types of uh places we can and and and why would we bother to make measurements from an aircraft? We have you could make a measurements from a ground station, from satellites, from unmanned aerial systems or drones and also from airplanes. Uh that's those are current methods that we use. Uh and first I'll go to uh ground stations and compare them. And here's a photo of a nice um network station that's around in Boulder as you can see. Um now with um a measurement on the ground you can get high temporal resolution continuous long-term record like the monoloa measurements of CO2 that have been going on since the 1950s. Uh however the air has to come to you and so you're a little bit at the mercy of um of mother nature to bring you the interesting data. And if you place it carefully, as has been done by my colleagues in EOL on many very successful uh um uh flux network experiments funded by the National Science Foundation, um you can you can place it well enough to really do some outstanding science. Uh but it's they're also not easily movable and and um stationary. Next we have um satellite measurements and they're super powerful. Uh you can get global or synatic coverage depending on the type of satellite. uh multiple scans um if it's geostationary multiple per day and and you get a moderate term of observations and by that I mean that you you get you it's you're not going to leave it up there for 50 years and take data for 50 years from the same satellite. Uh so it's it's uh not quite as easy to have a continuous long-term record with satellites as you do with ground stations. uh a it is it does come at a high cost for both uh uh creating and maintaining uh and processing well the processing data is the same and the resolution is a little bit coarse and clouds can obscure the most the the the phenomena you're interested in in some cases and sometimes you're interested in the clouds and then then that's okay. um for UAS's um they're it's super popular right now and it's an emergency emerging field in in observational science. They uh are highly portable, lower costs than some of your other uh platforms. Uh some of the disadvantages however are there's a short duration for most of the Oh, I didn't advance the slide. I advanced the wrong one. There's a shorter duration for the um for the small smaller drones like this uh hexacopter and and it has a limited payload capacity and it currently the FA is still working things out but there are some operational constraints in some areas. This particular video is of u uh a UAS measurement system developed in Eric's lab that uh it's called the UWAS and it's a it's a whole air sampler but it also has met meteorological data and it can acquire up to 15 samples in the MIDI cartridge uh for each flight and then you take the cartridges back to the lab and do offline analysis and determine over a hundred volatile organic compounds and so so we're super excited and they they were even able to patent this particular UAS. Now we're all airborne scientists. So I want to spend the most time focusing on airborne platforms. Uh and the advantages of airborne platforms are that you can get a high resolution 3D picture of all the gases that matter. Well, most of the gases that matter for the scientific question you're interested in and also particle distributions, uh size distributions and number concentration. You you can design your flights to measure uh vertical distributions all the way from the ground level to the lower reaches of the stratosphere. And airplanes can help you bridge a ground monitoring network data to satellite data. And we we take line measurements whereas the ground station take takes point measurements. [snorts] And the data we collect, if you construct your design your experiment appropriately, the data we collect can directly test atmospheric chemistry and transport models. Our payloads tend to include uh sophisticated instruments on the bigger aircraft to make measurements of of primary and secondary pollutants that Ali referred to but also some of the intermediate uh re intermediate species that we see out there like formaldahhide and also products some of the weaknesses. Oh, I forgot to say we can follow track l in a lrangeium manner. We can track emissions and see how the chemical composition changes as a function of time including how pollutants are formed as well as how the atmosphere cleanses itself by uh some oxidation reactions that occur there. Obviously, one of the ne negatives there are a couple I forgot to mention, but one of them is it it's not a great platform for long-term monitoring, at least the big he heavy heavy lift uh aircraft that we support. Um the the phenomena we tend to measure can frequently be episodic in nature. And so you have to always ask yourself the question, how representative are the is the data set that we collected? and you need to put it in a temporal context a of a longer term measurement record. Uh another thing uh that can happen is that these can be quite expensive to feel because we take a whole team of support folks with us everywhere we go. And now here are our airplanes. Uh our our I call this one our bus. Our uh four turborop C130 uh is a heavy lift uh transport category plane that we inh that we bought from the Navy for $1. And we outfitted it for uh atmospheric research including a research power distribution system and uh inlets that are appropriate for sampling uh gases and particles as as well as wing stores. the um I'm going to use this the um this pylon this uh pylon hanging down was originally a second fuel tank on on each of the wings. And we outfitted a research pod so that we can make measurements uh from wing locations both inside the pod and also from these canisters that we can mount up to three on that pod on each wing. The C130 has a maximum range of 2900 nautical miles in the way that we configure it. Um, uh, duration, flight duration, maximum of 10 hours. We can only go to 27,000 ft and once you load it up and make it aerodynamically heavy on the wings, that tends to drop to more like 25 26,000 ft. And our max payload with full fuel is 13,000 lbs. Once you once you fill it up on the inside, this is a photo of a recent experiment that we took and chemists uh fill it as as much as it as we can hold. We tend to hit the limits of weight. We hit the limits of uh rack space. We cram three together so that you don't have operators for the poor person stuck in the middle. And that's usually me. and um and so you can't do maintenance if if an instrument goes bad uh or suffer some other technical difficulty. But that's what a full C130 looks like. And uh their next aircraft is our G5. We call this one the Ferrari if the other ones are bus. [sighs] Uh it has um a similar 10-hour uh flight limit. 6,000 nautical mile range, 51,000. were certified to fly up to 51,000 ft. When you aerodynamically load the aerodynamic drag of wings, structures, and inlets hanging off the fuselage, it will limit your altitude to something more like 47,000 ft for max altitude. And you can typically only hit the max altitude for the last half hour of every research flight. And then the payload's about 6,000 pounds with full fuel fuel. And our rule of thumb is about two times the range and altitude and half the payload capacity of the C130. Next, this is a photo of the inside of the G5 for a relatively full project. Um, and you can see there are many fewer racks uh that will fit and the aisle is much narrower. Uh, on this 1C130 flight, we were we were up at 3 in the morning and trying to not fall asleep. So, we were doing jumping jacks in the aisle and the back of the airplane. You really couldn't do that in the G5, but it is a very comfortable ride. It's about half the noise level. It's only 65 dB inside the G5 when it's in flight. So, it's a nice nice aircraft as well. Other community aircraft, uh, we're going to present data today from the NASA DCA, which was recently retired. It's a it's an old brand of airline 707 that was modified and beefed up with with nicer engines to uh turn it into a research platform. Um and Ali's going to talk a lot about some of the very interesting data they observed recently on it's one of his last projects, maybe the last one. He'll he'll tell you. Um now then I just want to to put up again this view of the C130 empty of people but full of instruments and show you all of the ACOM um supported and EOL supported uh gasphase measurements. It includes actctinic flux which is basically uh a passive radiation detector and it can also detect uh uh photochemical reaction rates by uh mathematically um calculating them from the actctinic flux data. The Togat measures volatile or organic compounds. That's Eric's instrument. Um, I have uh uh the three major carbon species in one of these racks. An ozone instrument, another carbon monoxide, nitrous oxide, which is laughing gas. I measured that. And then Ali measures across the aisle NOx um all of the oxidized species of the sum of all oxidized species of nitrogen which is NO and ozone. Similarly in the front of the aircraft with uh that's that's on the left side but its name is on the right is an uh iodide chemical ionization m spectrometer which was recently uh developed here in house. This lovely uh graph created by Chris Cruzie of EOL is um kind of gives you a a map of all the flights we've taken between 2005 and 2024 on the NSF aircraft. And we covered a lot a big part of the globe, but you'll notice that the southern area uh on both sides of Africa are an understled part of the world. and we'd like to see that someday. We'll we'll we'll we'll work on addressing that at some point. Now then, the four experiments we're going to present data from are included here. And the first one is Gotham, which we did last August, and it was a New York City-based C130 experiment where we were studying regional air quality there. The Gotham logo stands for uh uh oxidant, trace gas, h hallogen and aerosol. I don't know what the M is metro area maybe. And then uh Asia air quality Asia AQ was an air NASA experiment on the DCA studying airborne and satellite investigations as well as air quality in Asia. The eclipse experiment is another Asian experiment uh where we focused on the upper tropospheric composition and dynamics in during the Asian summer monsoon. And then the fire mission was a local Boise Idaho experiment uh studying uh funded by NASA to study fire influence on regional to global environments and air quality. And now back to Ali. All right, remember remember this uh three ingredients to make ozone. Sunlight, NOX and VOCC. Um bear with me. Uh the ozone production is a nonlinear uh process as represented by this squiggly line. There not many straight lines over here. And nonlinear means that sometimes if you increase one of the ingredients you might have a decrease in ozone or vice versa which is very tricky. We like to to um think of that uh by using isoplasts that are represented here. They might look kind of weird. And this is a heat map, but you can think of it as a hiking map. And this could be your 13er you want to go up to or 14er, sorry. You want to go up to 13er if you're really cool. Um and uh but instead of um instead of wanting to go up, we want to go down. So the altitude is the ozone concentration and the east west can is the NOX ingredient and the north south is the VOCC ingredient and in this case we have a ridge most of the time we have a ridge that divides in two valleys a no sensitive valley and a VOC sensitive valley. If a hiker ends up in the no sensitive valley and follows the north south direction a VOC and we want to decrease the VOCC's for example we can see that not much happens in terms of altitude which means that the ozone stays the same but if we go east west the NOX way and we want to decrease the amount of NOx then we cross the isoliance and we decrease the goes and we go downhill which we want to do in uh vice versa. If we are in the VOCC sensitive area, we want to cross the isoline. So it means that we get a good decrease of ozone if we decrease VOCC's. So all of these now that you know all of these I can tell you about what we learned about Asia Asia IQ. So we we flew um over uh in a project organized by NAZA over four different countries. The Philippines, uh Thailand, um Taiwan and South Korea. And in this particular study, we focused on four mega cities, Metro Manila, Bangkok, uh Tynan in Taiwan, and the sale metropolitan area. We started from the data uh that gave us our starting point. Data gave us a good snapshot of what's there. And in order to give context with the data, we use a chemistry model, a box model that tell us on which mountain we are on which mountain those little hikers that are the data um are placed. And once we describe the status quo in this way with the data and the modeling then we can play the game of what if. We did it for four countries and uh we for all the four countries and then we played uh a game of what if and by modifying the model uh inputs then we looked at the outputs and we looked how much ozone would be produced if for example we will be decreasing um VOCC's by 20% and for Metro Manila we found that we we will get a decrease of about 5% % of ozone. Instead, if we would be focusing on decreasing NOx by 20% the same amount, we would get almost twice as much the decrease in ozone. So, in this case, for example, would be smart to focus on decreasing NOx. We did this game for all four uh of the of the locations and there are similarities and and differences. um especially um Manila and Taiwan are kind of similar in a in a way. Um um Bangkok uh sort of but for example in Korea if we look at the red line which is the NOx decreasing um attempt that would produce more ozone. So that's for example the wrong way to go. And uh this is a first uh a first uh sort of attempt at understanding the air quality in these four mega cities. Um and um and the next step will be to put this information in a transport model and look at sources to see which sources produce which VOCC's and which NOx uh which uh is going to be the next step. And back to Teresa. >> Our next example is going to focus on an experiment we did studying the Asian summer monsoon in 2022. And first I'm while I describe what we were doing, I'm going to show you a video of a simulation of the Asia monsoon that was put together by my colleagues in ACOM and also uh sizzle a sizzle colleague and I've [clears throat] given credit at the bottom to all of our guys. And the Asian summer monsoon is um it's a large convective system kind of continental scale that is seasonally c located over central Asia and it can transport gases and particles from the surface to the top of the troposphere and even into the lower stratosphere in some cases. In this case, the peak concentrations were about at 150 mil millibar, which is close to the top of the troposphere. Now, we uh sampled uh some of our biggest uh enhancements in uh in chemical tracers occurred in air that had been over East Asia and was transported uh by the monsoon into uh over toward Korea where we were based. And East Asian emissions come from heavily industrial industrialized areas. Eclipse was an experiment. The Asian summer monsoon chemical and climate impacts project was is a project that deployed a multi- platforms and some groundbased and balloon measurements to the uh peninsula Korean peninsula in order to study the outflow from the uh Asian monsoon. Two of the research aircraft that were uh deployed there were are the ENCAR NSF G5, NSF Encar G5. I got to get that right. I got to practice more. And also the NASA WB57 high altitude uh platform and it's not advancing. Can I Oh, there we go. If I can just show you briefly. I won't really talk about it much, but we'll go back to the slide that Ali covered very early where we talk about good ozone and bad ozone. And up in the stratosphere, ozone is a good thing. It absorbs and blocks damaging uh UV radiation. UV radiation that's high enough energy to to to create skin cancer, for example. Now this is a history of the ozone hole that chemistry humanmade chemicals uh were found to transport could that contain chlorine and I'm thinking of freons here in particular can be transported to the stratosphere and their reactions that they undergo uh that the chlorofllorocarbons ultimately destroy ozone and and that's what creates the ozone annually over um over uh I'm going to show this movie now because it shows the ozone hole over the southern hemisphere seasonally during southern hemisphere winter. Now the chemistry of is that that happens is a chain reaction. So the step that actually depletes the ozone and turns uh 03 into O2 uh is involved when a chlorine atom uh reacts with the ozone and pulls and pulls an oxygen off. Um and as a result of discovering the ozone hole, the Montreal Protocol treat developed the treaty that banned freons and other chloroarbons from uh being released into the atmosphere. And because of that, because of that success story, the ozone hole is now recovering. However, there are new threats emerging as and we discovered that and quantified some of that uh during the eclipse aircraft campaign. For example, a a chlorine containing compound called dchlorommethane, otherwise known as methylene chloride. It's an industrial solvent. It's emitted from the surface, but it's not covered by the Montreal protocol. It was not known to be involved able to it wasn't known to be uh of significant concentration at high enough altitudes to participate in destruction of the stratospheric ozone layer. It is however increasing in the atmosphere as a function of time and East Asia is is a large source of of dicchloromthane uh in the on globally. So what I'm pli I'm going to show you one of the results that was uh published uh not too long ago and it's a vertical profile of dicchloromethane that we sampled during the eclipse project. Um and the cyan data are shown on the vertical profile. Those were captured by Eric's Togat during the uh uh from the G5 platform. And the royal blue colored uh points in the vertical profile are data sample from the B-57. The red and the pink trans uh lines define for us the transition layer where the tropopause happens. And the uh red the black line is a is an estimate of where exactly the tropop the interface is between the tropopause uh troposphere and the uh stratosphere known as the tropopause. So, um, but what we saw when we looked at this data is that we saw unexpectedly high concentrations of dchlorommethane that made it up into the top of the troposphere and also as well into the lower stratosphere. Um so the success story is that the even though it's a concerning result a clip observations have helped us to identify a new threat to ozone hole recovery and that's it for me. Oh yeah. Okay. Um hello everybody. I'm going to switch gears a little bit and talk about um some other chemistry we studied. And so this is the Gotham study which um you heard a little bit about. Um it's it's a study we did. It's out of the New York City uh area. It was stationed out of uh Long Island. I'll show that a little bit. And this area is particularly interesting to study from a chemistry chemist point of view because there's a lot of different sources in the in the area. So there's um people who are familiar with this area know it's on the coast. Um there's marine influences on coastal cities. Um New York has huge you know urban concentration of of sources and but then you know if you got a little bit um west you'll just see these gigantic forests everywhere. So so there's lots of lots of potential sources there of interesting things that we study. Um, you know, we did this with the C130 and that's some of the crew there. And also, and this picture on the bottom kind of sort of uh highlights how urban dense this is. So, it's a picture taken at night and it shows all the lights, but on superimposed on that are the flight plans, flight paths that we did during this study, those blue blue lines. Um, I'm going to show you a movie and you can kind of climb into the C130 cockpit as we fly around in one of our one of our flights. Um, this is uh I'm going to I'm going to explain what's kind of going on as the movie proceeds. I'll have to stop it here and there. So, let's see. I think I have to do this. Okay. So, I'm going to stop it and tell you a little bit what's going on here. So, in the panel on the left, we have the C130 and um we are in the middle of one of our flight p plans. Um so, we started this flight out of Icelip, Long Island, right here. We flew over here, then we flew here, and then we went across Connecticut, and now we're heading towards New Jersey. Um, this flight path is colored by u a tracer for particles in the atmosphere. So, it's a UHSAS volume it's called. But the way to kind of think about that is is how much volume do the particles take up in a given volume. So, one way to maybe think about that is these like if you had a snow globe, you shake it and the the volume of the white little specks in there are kind of analogous to the volume of particles in the atmosphere in the air. So, um that's what we're looking at. But really all it is is it's a kind of a uh you know it'll it gives you a sense of what the pollution uh levels are and we can track that over here uh on this graph as we go in real time. So now we'll start the movie again. I'll show you where we're going. So we're heading down to um New Jersey and we're going to turn left and we're you can see what's going on over here. the the part the particles are are high here, but now we're heading towards the towards the ocean [snorts] and we're almost to the ocean and it's there's stuff starting to fall because the emission sources are less there. Now we cross into the ocean. You can see that on the camera and particles have gone way down. We do spinnies around and then then we head back to to land. And now what's going to be interesting to show you is we're going to fly up the Hudson um right in through New York, New York City. And I'll show in the next slide or next uh yeah, the next slide a little more detail of that. But this this will go fast. This is kind of sped up, but check it out. Check out the Manhattan skyline on the right as you go. And you see the particles increasing. And you know, we're we're flying at about 1500 feet, which is about the height of the buildings, which is kind of amazing. And here we go. And we're crossing. That was probably the George Washington Bridge, I think. I don't know. And then what we do is we we now are going to turn and we're going to head home. And so we go across the Long Long Long Island Sound and towards our landing spot. Um we also studied so we studied this area um both in the daytime but we also did nighttime flights. So there's a lot of interesting chemistry that happens at night and it influences what happens the next day. It can get the chemistry really started on on in the next day. So it's kind of brutal doing this. Um, you know, it doesn't sound that bad, but when you have when you do like a 3:00 a.m. flight, you have to get to the airport by 1 and then you have a long day ahead of you or a long night ahead of you and part of a long day ahead of you. So, it's it's pretty taxing to do that, [snorts] but we did it and pulled it off. Um, now I'm going to show you a little interest better movie of just going through this uh Manhattan skyline. And this is this is a testament to our pilots. Okay, I'm going to stop just for a sec. The reason we're doing this is because we're in a really like urban impacted area, but that area is also influenced by um uh by the biogenics which wind is blowing in from the from the west and it's mixing with the air that is the emissions from the urban center and there's emissions also coming from the uh from the ocean. Anyhow, so you could see this uh skyline. It's pretty. And you know, we never really got we did this a lot. We did this almost every flight. And we never got tired of looking at this crazy skyline. I think we'll see Central Park coming up right after this. Um really something. You could see these urban canyons. And you know these urban canyons really are a place where pollutants can be trapped as well. Um anyhow um okay so um another thing I'd like to just chat uh touch on is you know we did see some pretty clean air in New York and um we also saw times when you know the air quality was strongly affected by fires and so um you see this this these two photographs were taken within a couple days of each other and we saw a tremendous influence from those Canadian fires and you know I don't know some of you are from that area or something but this is kind of a new phenomenon you know from people talking talking to the people that grew up there and stuff they're like well we never we never really saw that when I was younger and stuff so but it's it's it's it's gotten their attention that this can you know these fires can impact their air um so we one of The things we do at ACOM in the community is we measure um you know we measure fires. [snorts] And so during this experiment which was uh called Fire X I guess maybe we' heard about that a little bit. We did on the DC8 um we targeted um really um detailed measurements of the chemistry of fire of smoke that comes from fires. And we did it for both western uh wildfires um which we we had this system based in Boise, Idaho and we did I think 13 flights and we targeted fires um for each of those flights and we also looked in the east out of Salina and we measured agricultural fires and so we got good chemical data on those fires and this is the way we did it. So this is we're in the we you know we do a lot of sat satellites help us to identify where these fires are um news sources um and we do a lot of atmospheric chemical modeling before we take the plane out. Here we took the plane out. This is looking at one of the fires which is uh burning in northeastern Washington. And then we can look at the satellite view of this as well. So this is the satellite view and it shows the smoke and we we we measure this um uh plume basically. So what we do is we go back and forth with the airplane and we measure the what's going on in for the chemical components of that plume and how those are changing as the plume evolves downwind. And in this case we see on the far right this is this is a this shows the track. The plane comes in and just transverses this plume. And what we get outside of the plume, you'll see these these cool colors show low concentrations. The warm colors are in the smoke and those are high concentrations. In this case, this is carbon monoxide. Um, but we also can measure a lot of other things. Um, one of the things of interest are hazardous um, air pollutants. And so um we have a means to measure a lot of those hazardous air pollutants. This um graph shows what we call a time series. So the concentrations are on the y ais. Time is on the x axis. And then here we're going in and out of plume. Well, here we're out of the plume. So the concentrations are uh kind of background levels. Here we're going in and out of plumes. And so all of these uh toxic compounds are tracking each other. So these fires are producing these compounds and we're studying them and we're finding out what kind of emissions rates that they come out in. Um and you know benzene uh benzene's here. Well, there's three of them right here. And also shown is is carbon monoxide as well. It goes up up and down with these as well. Um so what we do then is we take that data and we determine for hazardous pollutants for example um there it's a we can determine their emissions relative to carbon monoxide and so these for this is for western wildfires and what I'm showing you is this ratio to carbon monoxide for all of these fires um these these are the fires right here that we studied and this ratio remained pretty constant. So we can use that ratio then to um um model to put into our atmospheric models and then we can get a sense of what globally that those uh that particular compound what we might expect to see if we were to go out and study it and also gives us a sense of future experiments and what to look for. Um and and this and this is the global map over here on the right and this is showing emissions and it basically is a one-year um average of emissions um through and showing the fire influence of this particular compound which is ethylene oxide. I think that's all I had. >> Yep. >> Yeah. One more little set of slides about what the challenges that remain and um one of the challenges that still remain is predictability. Despite uh we have been uh working on modeling uh the secondary pollutants uh for a while, it's still hard to get to reproduce observe observed ozone trends in specific regions and in specific time periods. There is a lot that needs to go right in order to do that. We need to know the emissions well enough, the sinks, the chemistry, the methology, the transportation. Um so that that is still challenging in some in some regions and of course uh we have to deal continuously with ever changes ever changing conditions. Um the air that we measure today is not the same that we measured 20 years ago and it's not going to be the same of uh of the air that we're going to measure 101 15 years from now because the sources are changing continuously. And finally is uh the unders sample regions of the world. Uh last but not the least we are blind to large parts of the world. Uh Africa and South America are a clear example here for uh geostationary satellites. Um and when we have spars observations and that's the same for ground measurements and when we have sparse observations it's harder to validate models so the uncertainty of the models outputs becomes larger for these regions and uh in conclusion uh I want to point out that a lot of these results a lot of the work we do is possible because we can combine lab experiments model and observations in ACOM in ACOM and uh we are able to work really closely together within the same lab which is pretty special and if one of these um pieces of the puzzle doesn't work in synergy with with the other we end up with a puzzle that doesn't match and we end up with blind spots stuff we don't know we don't know sometimes and uh lastly uh none of these is a product of one single person. None of these none of this can happen in vacuum and it's a it's a constant effort of a team of highly driven people that are convinced that their work is important because can uh improve our understanding of nature of the environment and of our health. And with this I thank you for your attention and uh we are ready to get some questions going. You mentioned dicchloro methane I believe and the concern is that is a new threat to the ozone. How big a concern is it? >> Um it's it's not a gigantic concern. the concern is that it is going to um lead to a uh the ozone recovery will be slowed. So it's it's it's a you know it's it's what it is. It's a so the original freons were really longived compounds that would stay in the air and continually destroy ozone in the stratosphere. This is a what we call a shorterlived species. And so it's it has a lifetime of six months versus like many many years. And so the good news about it is it it can impact ozone. But the good news is that that's the bad news that it can impact ozone. The good news is it can be controlled. In other words, if you stop the emissions of it that it will very quickly um not impact the ozone anymore. >> And one thing I forgot to mention is that that that that chain reaction is catalytic and so a single chlorine atom can destroy several ozone molecules before it is taken out of the uh uh reactive state. So, >> so thinking back to those graphs you had about the cities in Asia with the nonlinear relationships, what drives the differences in the nonlinear relationships between different cities and what causes them to kind of react differently? One of the main differences is um the composition of those VOCC that we for simplicity we lump into one word but those are like hundreds sometimes close to thousands of compounds and depending on what kind of compounds you have in sort of these kind of zoo of volatile organic compounds that drives uh how ozone uh gets formed. All right, a question from Nicole is, "What inspired you all or each of you to follow in this career path?" >> Um, well, I I'm originally from Italy. I was born there and I was born in a specific place in Italy that is the poval. And if you look at a satellite image of a pali of any kind of pollutants, you see that it lights up uh because it's very pollutant polluted. It's it's enclosed between the Alps on one side like an arc and the other chain of mountains a panini on the south. So it's like a basin and and everything stays there uh mostly in the winter but also in the summer to some extent and every like everything like cooks there and uh so pollution was like every other day on the news and uh and that sort of uh drove me to study um atmospheric science to to tackle this these kind of issues. I would love to take the aircrafts in the pal and solve that puzzle. >> [laughter] >> Okay. So, I was in middle school. I'll tell you how old I am right now. I was in middle school when we had the energy crisis in the early '7s. And so, at that point, I joined founding member of my grade school ecology club. And so, that's when I developed an interest in in environmental science. And that laid dormant while I became just a straightup chemist, nothing gas phase. And then I wandered over to Encar and fell in love with the field and wandered over to Jeffco airport and fell in love with the airplane. So that's my story. >> And I came about a little bit more by accident than these two. So I I studied laser spectroscopy basically in in when I was in graduate school. We used to study small molecules like formaldahide and we would say this has atmospheric significance and that was about it. Um, and then, um, I moved did I ended up moving to Los Alamos and then to industry. And then my wife, who's sitting in the audience, she found a little ad for a job at Encar. And uh, she said, "You got to apply for that." And I'm like, "Yeah, I don't think I'd get it." Or whatever. And I did. And I ended up getting the job. And then um, I had a background in the chemistry part of things. And so it was kind of a natural fit. and then I kind of went went from there. >> Awesome. Thank you for sharing your stories. Um, any other questions in the room? I promise I will go to the other side too, just you know. >> Um, two quick question. One, we saw the inside of the airplane, but what what we don't know is how do you actually take the measurements? Do you have a little little things sticking up or how do you take the measurements? That was And then I have another question, but >> you want me to take that one? We we um our standard inlet is a 12-in tall pylon with what we call a cigar that is mounted uh parallel to the direction of air flow when the plane is in flight. And we stick a straw through there and we stick a pump on the end of it and pull air into the in into the airplane and into our instrument and spit it back out at the back of the airplane. And uh the thing has to be a foot off of the fuselage because an airplane moving through the sky distorts the pressure and temperature field. And so you really want to get out of that what we call the aircraft boundary layer so that we can do uh accurate sampling of free stream air that's not influenced by the movement of the aircraft. So that's >> and and the other question was what what about the freon that we have in our old refrigerators that hasn't how do they dispose of that and and and other how do we know other countries aren't still using freon? Okay, I'll answer that one. So, um there are methodologies that are enforced on in how you um manage uh freon that are have been in old refrigerator systems and so people are trained how to extract the freon from them from those old refrigerators and to destroy it. Um now there's leakages that happen of course and there's um it's been a number of years where you know we've seen incre so the atmosphere is being really actively monitored for these compounds. people can do highly accurate measurements of these freons and so we can actually identify um when there's more freons being uh you know a leakage or something and there's been instances in China where we've seen that and so there it's a combination of you know actively um you know taking care of the old freons but also actively monitoring the atmosphere and all in It's the Montreal protocol is holding very well. Most uh countries are abiding pretty well with with the guidelines and so it's it's a real success story. >> Thanks a lot for your talk. uh looks like uh ACOM as well as ENCAR generally has done work all over the world and I'm curious are do other countries or groups of countries also do the kind of monitoring and other work that you're doing and sort of the second part of the question is as support for basic research in this country uh further deteriorates what does that mean for this work being done generally and for the US's leadership in this area I know that's a mouthful You want me to take the because because uh the Korean project we did in 2022, there were a couple of Korean aircraft from their scientific organizations. The NIST equivalent is was one of them. And also there was a Japanese airliner making measurements, monitoring measurements from commercial aircraft. And so we have a lot of collaborators usually on air international projects. And when I went to Brazil in the mid '9s, uh we they wouldn't let us come in if we didn't have local folks and if they didn't own the data and so as well as making it publicly available, you know, after we're done. >> It's rare to have capabilities like this. Those are really remarkable capabilities that we're very lucky to be part of. Uh Germany has a couple of aircrafts. The UK just lost the capability of their own aircraft research. Um so and that really points out to you know the value that we have on our hands. uh especially when it's leveraged together with satellite with ground measurements with drones then aircraft gives you that you know top view that connects all those things and uh yeah and it's important to keep if you ask me >> oh okay right going to the little screen for a question online. What are the requirements for flying over a place? For example, Peru. So, I guess like here in the United States, there's the FAA that regulates um the airspace, but if you're traveling around the world, how does that happen? >> We we tend to negotiate diplomatic clearances for overflights uh uh over other countries and also over the ocean. that is not part of the international waters. Um, I'll give you another Brazilian example. Uh, we had to fly a Brazilian military observer on our flights to make sure we didn't go over their sensitive areas, you know. So, um, uh, it it's different in every country, but we but we try to negotiate um, under friendly terms. Some people are also careful with certain types of data because they don't want their mineral resources to be discovered. That kind of thing, you know, things like that. You have to think about their from from their point of view. What do they care about and how can we work together to to so that we all get what we think is important and what we need. All right, we'll take one more question online and then one more in the room. Um, so this question is, are there studies being done on how our rapidly changing atmospheric CO2 concentrations are affecting human cognition? >> Well, we're not the experts in that. >> Yeah. Um, you know, we we showed you this pie slice there and the pie slice, you know, we do measure CO2. >> Yeah. >> Um, and that's um, you know, Teresa measures it. Um, we, you know, this talk ACOM spends most of their time on those smaller slices, not you know, the reactive, we call them the reactive components. um you know CO2 has is going up dramatically and um it's a concern from many aspects. I didn't really know about that one. >> And the mean concentration uh to be toxic, it has to go up quite a bit more. >> All right, we'll take the last question in the room and then if you have more um our speakers might be able to address them after. >> Thank you. Uh thank you so much for wonderful talk. Um I I was wondering as someone who loves all the resources of a lab on the ground, what's one type of measurement or instrument that you wish you could have in the plane that you don't have currently? [clears throat] >> The list is probably long. [laughter] Uh >> so a groundbased instrument that is not on the plane, is that your question? >> Yeah. Yeah. something that you can't take into a plane currently that would give you a window into something you want to know. >> Okay. Well, I will start out by saying these planes um do have some of the most, you know, sophisticated instruments that are available. Um and we try to, you know, package them and make them as sensitive as possible because when you're up in the atmosphere, you know, the concentrations go way down. So you have to, as Olly was talking about, you have to have an instrument that measures down to parts per trillion for a lot of these compounds. Um, a lot of the groundbased stuff, you don't have to worry about that so much, which is great. Um, and the the information you get from that is great. So I'm sure there's lots of instruments that are um really useful groundbased instruments that, you know, may or may not translate to the air. Um and uh you know certainly our eyes are always open to you know looking at what could really be helpful for some of our studies. >> Yeah. The smaller they are the better they are because they take as the lighter they are the better that the more sensitive they are. The better they are because then we can go faster. We usually measure in 1 second which you know on the ground you can you can do one minute and it's not a big deal but we need to go fast. So, you know, everything that is smaller, more sensitive, faster, we like that. >> And chemically speciated vertical profiles by lidars would be awesome, right? >> Yeah, that's [laughter] a great example. >> Yeah. Well, thank you all so much and let's give another round of applause to our speakers [applause] and thank you all again and I hope you enjoy the rest of your night. And we still have a little bit of sunlight outside. So, have a great evening. [music]