 Welcome to the Longmont Museum on the Internet. The Longmont Museum is the Center for Culture in Northern Colorado where people of all ages explore history, experience art, discover new ideas through dynamic programs, exhibitions, and events. My name is Justin Veach. I'm the Manager of the Museum's Steward Auditorium, and we are not coming at you live and direct from the Steward Auditorium this evening. We're coming at you live and direct via Zoom, which explains why I'm at home right now. And while you're at home too, probably. Anyway, tonight's program is being offered as part of our Thursday nights at the Museum series. That's right, every Thursday night at 7.30 p.m. we offer a little something, a panel, a lecture, a conversation, a reading, a performance. You name it. And these programs are made possible by the Scientific and Cultural Facilities District, the Steward Family Foundation, our museum members and museum donors, as well as our media sponsor, the Mighty KGNU out of Boulder, just down the road. Tonight's program is being presented as part of our ongoing collaboration with the National Center for Atmospheric Research, otherwise known as NCARS, Explorer Series. We're very glad to partner with NCAR to present two programs a year, one in the fall and one in the spring as part of their Explorer Series. And tonight's program is the Air We Breathe on Front Range Air Quality. And we'll be joined by scientists Frank Flocka and Gabby Fister. I want to mention that at the end of the program, we will be taking Q&A. So if you have any questions and you're watching on Facebook, please enter them into the comments and we'll be sure to note those questions and pose them to Frank and Gabby at the end. All right. So on with the show. Frank Flocka has been working as a scientist in the Atmospheric Chemistry Observations and Modeling ACOM Laboratory at NCAR for over 20 years. He came to NCAR from the Institute for Tropospheric Chemistry at Research Center, Jules in Germany, after receiving his PhD from the Wuppertal University in 1992. Using mainly aircraft measurements, Frank has been involved in research in the field of air quality pollution transport and chemical interactions and transformations of anthropogenic and natural emissions and how these processes change the chemistry and composition of the troposphere. He served as a principal investigator and chief aircraft scientist for the Front Range Air Pollution and Photochemistry Experiment, otherwise known as FRAPE in 2014. Gabby Fister received her PhD at the Carl Frenzen's University in Graz Austria and has been at NCAR since 2002. Her expertise is in the integration of measurements from satellites, aircraft, and ground with chemical transport models to investigate the links between local, regional, and global air pollution. By combining modeling with satellite and field campaign data, she has made important contributions understanding regional and local air quality, including impacts of natural sources in relation to contributions from human activities or transboundary and long range pollution transport. She is also a principal investigator on FRAPE. Ladies and gentlemen, please welcome Frank Flocka and Gabriel Fister. Thank you very much, Justin, for inviting us, for giving us the opportunity to speak today. And yeah, I'm excited and I look forward to the next hour, hour and a half to exchange information about air quality in the Front Range. It's great to have you. Thank you. So, Frank, if you would like to start us off with the slides, maybe. Yes, good evening, everyone. Thanks for being here. I'm going to try and share my screen. And I hope you are seeing our presentation now and I will give it back to Gabby to start out the presentation. Okay, well, thank you very much. So we are here to discuss a topic that's really of relevance and importance to all of us, and that is the air that we all breathe. When we talk about Front Range air quality, there are two questions that come to our mind. And Frank, if you can please advance. Yes, here we are. So the two questions that come to our mind are how healthy is the air that we breathe? And the other that comes to our mind is, well, we have one of these beautiful clear sky days in summer, where we all want to be outside and enjoy the outdoors. When I have these blue skies, do I still need to worry about the quality? It looks pretty clean to me, right? So the very short answers, our air is better than it was years ago, but it's far not healthy enough yet. And yes, also on these blue sky days, we have to worry about the air quality, because our main pollutant is ozone. And ozone is an invisible gas and is often highest on the clear and sunny summer days. So that's the short answers. But in the next hour, we are going to look a little bit more in detail into the more lengthy answers to these questions. We are going to tell you some basics on air pollution and why we do care about ozone and also how it is formed in the atmosphere, which is very important to know. We want to know about the characteristics of ozone pollution in Colorado, and we want to know what we know and what we don't know. We want to demonstrate to you how research can support policymaking and finally also discuss what steps each of us can take towards cleaner air. So let's get started with some definitions. So when we talk about air pollution, we are not talking just about one compound. We are talking about the range of different compounds that include six criteria pollutants, which I'll talk a little bit more about them. And as well, we talk about air toxics and volatile organic compounds. The complication with all these pollutants is that frequently one or more of these occur together. You might have a high day where you have one pollutant, where you have multiple pollutants, and some of them share the same sources and some don't. So it's not just one fits all scheme. So what are these criteria pollutants? Criteria pollutants are the six listed pollutants here, carbon monoxide, sulphur dioxide, nitrogen dioxide, lead, ozone, and particulate matter. All of these criteria pollutants have negative health effects, and they are regulated in the US for the Clean Air Act. So our main focus for today is going to be on ozone, because this is also our biggest concern in the Colorado Front Range. When we talk about ozone, we need to make another distinction and we need to look at primary and secondary pollutants. Primary pollutants are those that are directly released from the source into the air. So you can imagine if you have another pollution coming out right from the source and the further away from the source it gets, the more diluted it gets. So you have the largest impact of this primary pollutants right near to the source where it's being released. Secondary pollutants and ozone is a secondary pollutant. They are not emitted from any sources. They are formed in the atmosphere from what we call precursor emissions. So you need to emit something in the atmosphere that then forms ozone. And that makes it more complicated, because now the impact of secondary pollutants like ozone can be highest much further away from a source. So it's not necessarily right where the source is. So why is ozone such a big concern to all of us? Because of its very serious health effects. High ozone mostly impacts our respiratory symptoms, your system, which leads to symptoms such as inflammation of airways. We start coughing, we get soreness, scratchy throat. You can start developing pains with deep breathing and it also aggravates asthma. As a result, it impacts our lung function and our growth, which increases emergency room visits, hospitalizations, and a number of sick days. Exposure to ozone can increase the risks of permanent lung damage, premature death, and cardiovascular effects. And the health costs associated with it can be ranging in the range of millions of dollars. It's not only us who are impacted by high ozone, but it can be also our environment. For example, high ozone interferes with the ability of plants to produce and store food. And Frank, if you stay on the plants, then that makes life easier. Yes, here we are again. And this compromises the growth, the reproduction, and the overall health of our plants. This makes the plants also more susceptible to diseases, to pests, and to environmental stresses. Again, here we have a huge economic impact in the range of billions of dollars. Just imagine all of our food production is impacted by high ozone concentrations. Now, ozone, we said, is an invisible gas, so we cannot see it, but there is a way to make the pollution actually more visible. And one such a way is an ozone garden. And one of these ozone gardens we have at the Anchameza Lab. There is actually also one at CU Boulder. And an ozone garden is really what it says. It is a garden with different plants that have a different sensitivity to ozone pollution. And here I just show an example from 2015. On the top is an image from early August, where all the plants in the garden look very healthy. And that was before there was very high ozone pollution. A month later, early September, that was after an August of very high ozone pollution, lots of wildfire smoke in the area. You can see that some of the plants that are more sensitive to ozone pollution have been suffering serious damage already. Well, some other ones, the reference plant in the back, still looks pretty healthy. So an ozone garden is a really good way to visualize the impacts of an invisible pollutant like ozone. So now how about the quality in the U.S.? Over the recent decades, there's been the U.S. has actually really made a lot of success in cleaning up our emission sources. This is due to emission controls, but also due to advanced technology. And just think about our cars. They have gotten way, way cleaner. And you can see that it's also from space. Spaceborne measurements are really an important aspect to monitor and characterize our air pollution. So here you see nitrogen dioxide, which is emitted mostly from traffic, industries, human activities. And you see here the concentrations for 2005 I've seen from space by the OME instrument. And you can see in red are the really high concentrations. And you see this really high values over the east coast, California, and you see also Denver popping up here. Now let's compare the 2005 picture to a more recent one, 2019. And you can see that this, the very high concentrations that were indicated in red significantly have gone down and also over the Denver area. We can also look at just the concentrations over the Denver area as a time series going back to the early 2000s. And you can see this clear decline in NO2. Also, if you look at that a little bit more in detail, we can see that the reductions seem to have been leveling off over the recent years. We also see this reduction in emissions in the number of high pollution days. So here I'm showing you a graphic that comes from the US EPA that shows you going back to 2000s, the total number of days where the air quality in the US has reached unhealthy levels for sensitive groups. And you can see that that's really good. There's been an overall downward trend in this number of unhealthy days. So great, right? Problem solved, nothing to worry about. Let's all go home. Not as easy. So because if you look at this statistics here, also from the US EPA, which gives you the number of people that are living in counties where the air quality levels are above the most recent standards. And these are data for 2019 here. And you can see that there's over 80 million people in the US still living in counties that violate one or more of these health standards. And for ozone, that's over 70 million people. So the major concern also across the US is actually exposure to ozone. So by far, we cannot say yet that our air is healthy. Our air has gotten better, but it's by far not healthy enough. So I list this acronym here, this NAAQS, the NEX. This stands for the National Ambient Air Quality Standards. And let's just look at a few numbers so that then further into the talk when we show various results, you also get a better feeling for what is high and what is low. So the health standards, the NEX that's set by the US EPA, has been revised over the over the years as health studies have given new evidence of higher or lower thresholds. And it has been an hourly standard in the range of 80 to 120 PVB back in the 70s. And has now been the most recent from 2015 is a standard of 70 PVB averaged over eight hours. So this is the value where we say if you are below, we can't say that it's healthy, but it's probably not of that much concern. But if you're above 70 PVB, then definitely we have to start worrying. We can compare that to standards in Europe or in Canada, which are actually below our standards here, even the most recent lower 70 PVB standard. And that's also the WHO, the World Health Organization, has actually a much lower standards that they recommend that would be 50 PVB. 50 PVB would be pretty tricky to achieve, given that the ozone in the remote atmosphere, let's say by far out of a Pacific Ocean or somewhere, is in the range of 20 to 40 PVB. And the background ozone in Colorado, which means the ozone that comes in from outside of Colorado and bear be on top, create our own pollution then is already in the order of 45 to 50 PVB. But still, if this background is 45 to 50 PVB, what comes in the Colorado, we still need to create at least 20 PVB of our own ozone, so to speak, to get over the 70 PVB threshold. So how does ozone in the front range look? How well are we doing here? So what I'm showing you here is going back to the 1990s, the what we call the policy relevant eight hour ozone, which is an ozone where we look at three consecutive years and look at the forest highest daily eight hour maximum. Sounds complicated, this kind of complicated, but that's the standard that's set by the US EPA. And here you see in the different colors, you see this policy relevant ozone at different monitoring sites across the front range. And what you also see is in the dashed red line, the health standards that, as we said, has been higher and over the recent years has been reduced down to 70 PVB. First, what you can see is that, well, there isn't really this clear downward trend in ozone that we see in the front range. And the other one you see is that with the next going down, actually now pretty much most of our monitoring sites are above the health standards. So yes, we do have a problem here in the front range. And the problem has actually also been recognized as getting worse by the US EPA. And the front range has been in for many, many years now, declared as what we call a non attainment area for ozone means for many years we have violated the health standards for ozone and have been declared as a non attainment area. And this last year we were bumped up to from a moderate level to being a serious violator of federal air quality standards. We are not alone in this category session, you see Los Angeles, Texas, also some areas on the east coast. But it's definitely not a label that we want to carry with us. So now I've talked for I'm not sure how long, but probably for a long time how bad ozone is. And now you're probably wondering, what is she talking about in the news that talk about the ozone is shrinking and how bad it is in the Montreal protocol and she tells us how bad ozone is. Well, and that's where maybe we should take a step back and say, the tail of two ozone there is a good and there's a bad ozone. The good ozone is that ozone that we really want to have a lot of it. But that's not down here at the surface that good ozone is located in the stratosphere. And the stratosphere is a part of our atmosphere that's about 15 miles above our heads. Up there we want to have a whole lot of ozone because that's where the ozone blocks damaging UV radiation. And actually without having ozone up there, none of us would be here. Down here where we are all living and breathing, that's where we don't want ozone because that's where it is damaging our health, that's where it is damaging our ecosystems. So up there, very high up 10, 15 miles above our heads, all the ozone that's that's where we want it. Down here, we don't want to have the ozone. So just to make sure that you understand the distinction. And we are here talking really about the bad ozone, that ozone that we have around us where we live and breathe. So now, how is ozone created? I mentioned earlier, it's a secondary pollutant. So ozone needs ingredients, like you need ingredients to bake a cake, you need ingredients to form ozone. And the ingredients are emissions of nitrogen oxides, NOx and of all the telegenic compounds, VOCs. And they are being emitted from a number of different sources. Most of them are human activities from industry and traffic. There is also wildfires and plants actually also emit a certain amount of all the telegenic compounds. So they all get into the atmosphere from these multiple activities. Then we need sunshine. And here you are and we create ozone. Seems pretty easy, right? So what's the complication there? Well, it's actually quite a bit complicated. And when life gets complicated, I like to take the backseat and I'm handing over to Frank. Thanks, Gaby. So I'll take over the chemistry here and tell you a little bit more about how ozone is created. And I call this the ozone machine. And the ozone machine runs, and Gaby already alluded to that, runs on sunlight, on VOC, and on NOx. And here is how it works. When VOC gets into the atmosphere and the sun is shining, the sun enables certain radicals to be formed that enable VOCs to react with oxygen and essentially get burned, oxidized in the atmosphere. And one of the intermediate products of those is we call those peroxy radicals. They are VOCs that have an oxygen hanging off of them. And this oxygen can get transferred to NO and turn NO into NO2. So the VOC and the NO are the primary emissions. And then NO gets oxidized to NO2 by burning a VOC. That VOC becomes an oxygenated VOC and it can go back into the cycle and it goes around and around until it ends up as CO2 or possibly rains out or goes on an aerosol or something, but it gets totally oxidized and taken out of the atmosphere that way. This is our cleaning process. Unfortunately, during this process, NO gets oxidized to NO2 and when the sun is shining on NO2, one of the one of the oxygens on NO2 can get transferred to oxygen and turned into O3, which is ozone. And so this keeps going around and around and around as long as the VOC are being fed in. This NO and NO2 are going around and they're churning out an ozone every time they go through this cycle. And as long as the sun is shining, as long as you have fuel, as long as you have an O and NO2, this keeps going. So to put this in writing, the NO and NO2, they are essentially the truck to bring the oxygen atoms to O2 to form ozone O3. And O and NO2 are interconverted in the process, but they are not destroyed. So they kind of are the catalyst for the ozone formation, if you wish. The VOC, and there are hundreds, if not thousands of VOCs emitted from all kinds of sources, as Gabi already alluded to. I get into this a little bit more in to detail later. They are the fuel and they are burned in the process. They're oxidized. And ultimately, this results in their removal from the atmosphere. This is the cleaning process of the atmosphere. The sunlight is the accelerator. It's needed to keep the chemistry going. The more sunlight you have, the faster the chemistry goes. And the relative amounts of the fuel and the catalyst and the composition of the fuel, that means the composition of the VOC, the composition of the emissions, they determine how much ozone can be formed in polluted air and how quickly it can be formed in polluted air. So to address our ozone problem in the front range, and here again is the outline of the non-attainment area. Non-attainment area, those are the counties that frequently violate the ozone standard here, and they are therefore designated. This is Boulder, half of Laramine. We're County Adams, Rapport, Douglas, Jefferson, and Denver County. So this is kind of like where most of the people live. We want to know what are the drivers behind this summertime ozone? Where are the VOCs coming from? Where is the NOx coming from? And how does it conspire to make ozone here a problem? So the questions we are looking to answer is what and where are the relevant sources? How are these sources mixed together and where are they transported to? How are they chemically processed in order to form the ozone? We also want to know how much pollution comes into Colorado from the outside. Does it play a role? Is it really a factor? And then of course, finally, we want to recommend ways to improve the air quality around here. So the challenge for air quality management normally, for regulatory agencies, when they are trying to get a grip on their air quality problems, is that the atmosphere is three-dimensional. But the measurements that are done of air quality are measured at the surface at fixed sites. So for example, throughout the non-attainment area, there are 10, 15 sites that measure ozone. There are a few that measure particles. And very few pollutants are measured on a regular basis. The atmosphere, however, is a three-dimensional system. Pollutants move and mix vertically and horizontally. And all these processes are time dependent. Many of them are non-linear. They conspire together. It's a very complicated problem. And with just measuring a few pollutants in ozone itself, you can't really get to the bottom of this very easily. Also, there's not just NOx and VOC. As I already alluded to and Gaby said, VOC are comprised of hundreds of different species with varying roles and varying speeds of chemistry with which they react in the atmosphere. And they come from different sources. So this is a complicated system that needs to be looked at. Another thing is that reducing VOCs or NOx, one of them, doesn't necessarily decrease ozone. Sometimes the ozone even increases because the chemistry is dependent on the mix of ingredients and not just on how much of one or the other is present. So we have to be a little smart about where and how we reduce emissions and what the best impact is and what we do. So this is where a scientific field campaign comes in. So the Frappe campaign took place in 2014, can't believe this is over six years ago already, getting pretty good mileage out of that, between in July and August of 2014. And this was a collaborative effort between the state of Colorado, the EPA, NCAR, NASA, NOAA, the National Park Service and many university partners. Gaby and I were, and I hope you can see my mouse here. Gaby and I were the principal investigators for Frappe and we were able to convince NASA to come and play with us for the time that we were out in the field. They had a campaign going on to enhance the utility of satellite measurements for ground level pollution prediction. And they had already done three experiments in this framework and they were looking for a place to do their fourth. And because we were doing ours, they came and helped us and increased the number of resources that we could throw at this problem by quite a bit. The funding sources for these are, you know, as I already mentioned, the National Science Foundation funds NCAR, the state of Colorado contributed the lion's share of the money to fund our aircraft mission and the university partners, discover a queue was funded by NASA and then all these other agencies were also involved in funding for this. Aside from ozone, we also looked into some other front-range air pollution issues, which we won't talk about this time, but we looked at benzene toluene, you know, other air toxics that are coming from industrial activities and oil and gas activities. We looked into methane, looked at emissions from concentrated animal feeding operations versus oil and gas emissions, and also front-range nitrogen emissions that have been shown to contribute to fertilization of lakes and ecosystems in Rocky Mountain National Park, which can have unforeseen consequences. So what field campaigns do for you, they give you a high resolution 4D picture of the atmosphere from close to the ground to high in the atmosphere. We can, with our aircraft, we can follow the pollution plumes, we can fly repeatedly over the area and look at how the emissions compare with what we predict with our models. We can not only measure the emissions themselves, but we can measure also the intermediates and the products. There are other products, other than ozone, that can tell us how well we are doing trying to predict the air quality. So what we had is we had the C-130, which is the main aircraft I'm talking about today. We had three aircraft from NASA that were doing various things, including remote sensing and satellite work, these two aircraft here, and also in situ polluting measurements from their main aircraft, the P-3. We had the stations from the state of Colorado that are always measuring anyway. We augmented those with additional measurements on the ground. We had tethered balloons that were measuring the lower atmosphere where our aircraft can go very easily. We also had some mobile labs that were mounted in trucks that were driving around and could look at individual sources, like the refinery in Commerce City or some of the feedlots or some of the oil and gas sites. We had measurements at the Tower Tower in Erie, which is unfortunately now gone. That was really a great place to do experiments out here because it's centrally located and it allowed us to make measurements up to a thousand feet in elevation of the ground. This is what it looks like in the aircraft. I just wanted to give some of you an idea. We have all these instruments mounted in the aircraft here when we fly. All these measurements are being done while we fly in real time. This is while the instruments are warming up and being calibrated and before we go fly, we do this about for three hours on the ground. Make sure everything's working all right before we fly. It's really not fun. You're sitting in an aircraft down in front of your instrument. You can't see where you're going. Some people are lucky enough to have a window, a small window where they can look outside, but it is really not a joyride by any means just to give you an idea on what this looks like. So what are the air pollution sources in the front range? We all know about the extensive oil and gas activities that are going on in Weld County to the northeast of the area. Here we also have embedded in those oil and gas areas. We have concentrated animal feeding operations of feedlots, dairies, and you can see here these pink dots. Each of these pink dots is an active oil and gas site. This is for 2014. At that time, there were about 30,000 of them across the northern front range. We have a number of power plants, some of which have been shut down in the meantime, but they were still all operating in 2014 industrial areas. And of course, we have all the traffic and everything being moved around and all the urban emissions and the highway emissions from the major activities here. If you look at this from the aircraft, this is here the power plant. This is the Rawhide power plant up north that's sitting pretty much by itself, but it's not always this easy. You can see here there's a large feedlot here and right along this feedlot are three new well sites being put in. And here's already a very large processing facility being built of oil and gas. And so those emissions are harder to tease apart. And it requires some trickiness with how you fly and how you design the flight plans to tease this out. And then of course, there's the urban area where you can see the main conglomeration of the urban area here plus the industrial area along I-70. We have the refinery up here and we have DIA out here. So in order to find out which emissions are the responsible ones, we go back again to just refresh your memory. We knock some VOC in sunshine. We have plenty of all of these three ingredients in the front range, but we want to know which of them contribute how much to our ozone problem. So normally when we don't have the research going on and just the ground based observations I alluded to this earlier, what we have to work with is very limited ground observations from a observation network that is run by the state. And there are a few sites here. You'd see those white dots where ozone is measured and a few other things. We have an emission database that emission database comes from often self-reported emissions. There's very few places that have actual read of time monitors on them, just power plants and a few other things. So the industry often self-reports emissions. Some of the emissions are estimated. We know from our aircare program roughly what comes out of our cars and we know how much traffic there is, and so we calculate those emissions and we stick this into a model and see how well the model does for producing the few ozone measurements on the ground we have. And that's really all we can do. Very often this is not an ideal. You really cannot really grasp what is happening here. And you can see this is a model here of a tracer that is being emitted and you can see how this is transported around and you need to get this from just a few points on the ground and that's really very, very hard to do. So if we have comprehensive observations we are much better off. So from the aircraft and the satellites and with high quality observations we can measure the meteorology, we can measure the wind in 3D and we can measure all our emissions and all our chemical products. So we can look at our chemical processes and we can refine and evaluate them with the model using our measurements and see that everything has to fit together. We can also evaluate and compare our emissions. So we can look at what the aircraft sees and what the model predicts it should see based on the emission inventory that we feed into the model. And if that is not right then we can use our aircraft measurements to adjust those emissions and make them more precise for our problem. So what we then can do once we have our emissions and our chemical processes and everything nailed down then we can use the model to create robust pollution control strategies and and eventually you know have cleaner air as a result and how we get there I'm going to tell you now how this process works. So let's start with the meteorology. So we have a relatively complicated meteorology in the front range which is driven by our north-south oriented mountains. So what happens in the morning when the sun comes up, the sun warms up the slopes of the Rocky Mountains and that creates what we call an upslope flow. It creates a heating effect that pulls air up into the mountains and essentially this little vacuum that's being created here pulls air from the plains over all our emission sources into the mountains where it then can react with either the overall flow from the west that is the prevalent flow from the west to east in the free troposphere so it can be turned around and maybe mixed down back into the front range and react more or it can get over the mountains and flushed into the valleys on the western side and you can't really figure this out until you throw an aircraft into the mix. So let's look now at an aircraft flight track and this is a little bit complicated. So the red colors are high concentrations of whatever we're looking at every you know the molecule of interest here or the emission of interest. The blue colors are low concentrations. These little barbs here are the wind direction. This is the wind goes from east to west as you can see here and the reason they are stacked on top of one another is that we flew the same pattern at different altitudes again and again with the aircraft. And this flight track here is colored by ethane. An ethane is a tracer that is almost exclusively emitted from oil and gas operations and what you can see here is that this transport this airflow from the southeast to the northwest transport this ethane which is really high over the oil and gas area transports it efficiently into the mountains here you know into west Larimer County and northern Larimer County as we fly with the aircraft. Down here and then where the ethane concentrations are are comparably low. Now if we use the same flight track and color it by NOX emissions you can see that the urban emissions from all the traffic and all transportation including power plants you can see the NOX is higher in Denver but there's also high NOX in Greeley and downwind of the oil and gas operations because there's also quite a bit of truck traffic here. There are compressor stations and various generators and those are used in the oil and gas but also in the NOX but again the NOX emissions in the urban area are much higher. However if you color this now by ozone you can see that both the oil and gas area which is more transported this direction also the urban area efficiently produce ozone downwind. You can see right over the area the ozone hasn't been formed yet but as the air travels the ozone is getting higher and higher as we go into the mountains. The other thing we can see here this particular flight we did a missed approach on the airport in Grandby here in the Fraser Valley and you can see that the ozone in Fraser Valley is also high and as I will show you in a little bit this is a result of transport of air masses across the continental divide into the adjacent valleys. So if you look at this flight track from the side now here is the profile the altitude profile of the here's the continental divide here's the Fraser Valley Denver is here Greeley is here and these are the same flight tracks colored by ozone again just looked at from the side from the south looking north and you can see that this upslope flow transports the ozone up to the mountains over and spilling over into the Grand Valley. At the same time you can see this flow being caught up in the westerlies which is this flow that goes comes across at high altitude and it's being recirculated these are the model results for the same day and you can see that the model does an exceptional job of predicting this on this day. So this is one of those days where we can use the aircraft observations to make our model smarter and the model predicts everything correctly we can go in and compare everything that the model has our emissions and all these things with the input data that we put in and see whether this input data needs to be adjusted in order to get our ozone right. So when we do this now we start as far as emission inventories go we use this these aircraft observations compare them with what the model predicts we should see and we do this you know often enough we get enough statistics on our emission inventories and our flights pointed to arrows in those emission inventories. So what we did is we started with the best estimate based on the EPA and CDPHE data the CDPHE is the Colorado Department of Public Health and the Environment they're the ones that create those inventories together with the with the EPA and our observations could only be brought into agreement with the predicted amount of pollutants if we increase the NOx emissions from traffic outside of the Denver urban area so up in Fort Collins and down south of Denver by a factor of two. So the NOx emissions as estimated in the emission inventory for outside of Denver were much lower than what our measurements showed we also had to double oil all oil and gas natural gas emissions except ethane and that shows us something that actually the pipeline leaks are pretty well known but all the other emissions from the oil and gas operations are not so well known so we had to double all those emissions we also had to make some other smaller adjustments to the individual species and so now what we have we have a model that adequately predicts our metrology and we have an emission inventory that has been adjusted and essentially made smarter so we have the correct emissions we have a good representation of the metrology in the model and we understand the chemical processes in the model so now that we know that and we have everything verified we can use the model to play games with those human cost emissions so one of the games we can play is we can say here on the left side is our eight hour average ozone over the average over the entire campaign period and again the warm colors here are high numbers and the cold colors are low numbers and you can see this 45 to 50 parts per billion ozone background that's being transported in from the west at high altitude the mountains are here this is our continental divide right here and you can see that our ozone in the front range is elevated and on average again should quite close to the 70 ppb standard even on average so what would happen if we turned off all human cost emissions in the front range and this is what this graph shows this is the reduction of ozone that would be achieved if we turned all human cost emissions off and if you look at those numbers here there are somewhere between around 15 parts per billion 15 to 20 parts per billion so if we subtract 15 to 20 parts per billion from this we are at the background so what this shows us is that our ozone problem is homemade all of the ozone that is pushing us over the edge pushing us over the the air quality standard is produced from our local emissions it's not brought in from anywhere else we can do the same thing for a high ozone day so this is a high ozone there's a 28 of july of 2014 and you can see that on this day much of the front range was above 80 parts per billion and again if we turn all the human cost emissions off we reduce our ozone by almost 40 parts per billion here so we go back to the background so this holds true for for average for high ozone days for low ozone days you can do this and you can see this is all homemade so there's no transport we are all responsible for our own problem here now we can also go a step further and we can turn off individual sectors so this is for that same day for the 28 of july and you can see again what the difference would be if we turned off individual sectors here so let's turn off all the oil and gas sources if we turn off all our oil and gas sources and again we have the the the high numbers here are about 10 excess of 10 parts per billion so the oil and gas sources alone would bring ozone down by more than 10 parts per billion in this area here if we turned all our mobile sources off so we all would stop driving and transporting things around we would also achieve a dramatic reduction in ozone across the entire front range again with a little bit more emphasis on the city here whereas the oil and gas has a little bit more emphasis on the north because of the physical separation of those two sources if we turned all our industrial sources or all our power plants off you can see the impact is visible but it is much smaller so what we conclude here is that traffic and oil and gas are our main contributors to ozone formation and about 40 percent each of those and with that i will turn it back to Gaby right thank you very much frank so now frank has shown us that traffic placed really a very important traffic and oil and gas are the major contributors to our ozone pollution problem so now we would think that with covid and the restrictions that came with it and many of us no longer commuting and you know not driving around from restaurants or shopping you would think that that really has helped our ozone problem right so well let's look at that so this is now some preliminary analysis that we have been doing but I think it's some very eye opening results that we see here so what i'm showing you here is a graph of traffic counts so there is various stations in the Denver area where you are measuring continuously the traffic numbers and this is from one of the stations on i-25 and 6th avenue and i'm showing you here traffic counts that go back to the early 90s and the earlier years are in lighter blue color the later years are in darker colors 2019 is in a very thick dark blue and 2020 is shown as this red line uh frank you are too fast thank you and what you can see is that if you look over the course of the year that we see in 2020 compared to 2019 we see a significant reduction around april which goes down to about 40 but then it recovers fairly quickly around june and it's really only about 10 at the most 20 lower than in 2019 so if we think about how significantly covid and the restrictions have impacted our life the reduction that we see in the traffic has actually been by far not as dramatic and maybe one other point that the also one to make here is if you look just at the different years you see the significant increase in traffic over the past 20 years so for those of us who have been living here in the front range for the last 20 years if you had the feeling that things are getting more busy well things have gotten way more busy um so yeah so how this this change in traffic now impact our NOx or in this case I show measurements of NO2 which is a major part of the NOx and as we know now a precursor to ozone production so this is just examples for measurements at an i25 hybeicide in denver in red you see the observations for 2019 and in blue you see the observations for 2020 and overall we see that the change in NO2 is in line with the change in traffic counts where we see some of this largest difference or the larger reduction in 2020 for April and May but we also see that the difference is actually quite smaller than what we've seen from the traffic counts and what we assume and believe is because of the different contributions of track traffic versus passenger cars overall track traffic has a more significant contribution to NO2 emissions than passenger cars they are just basically more more dirty they are mid more fuel they are much heavier much bigger um and our transportation of goods hasn't really changed that much um so it's really this in you know this this relative difference between the track traffic that hasn't changed that much and the passenger cars and the fact that passenger cars just emit less NO2 than track traffic that causes this discrepancy between traffic counts changes and NO2 changes um better also impacts our chemical concentrations and we have done a very preliminary analysis and that indicates that better played really a minor role to these changes so did this so the changes are rather small did it help with our ozone well that's where we need to go back that we need sunshine to create ozone and the highest ozone concentrations we find typically in summertime and that's really when the changes in NO2 were not very pronounced on top of that 2020 had a very high number of hot and sunny days we had a really extreme hot and dry summer everything that really helps to produce ozone and then when you look at the graph here that's from the regional air quality council you can see that for 2020 the number of high ozone days indicated in orange and yellow is actually has actually been higher than in 2019 and was actually definitely higher also than some of the other years so really COVID as much as it has impacted our daily lives and our you know we have the feeling that nothing is the same it unfortunately has not really helped with our ozone problem um now I want to just take one other side step and that is we have talked so far everything about summertime and ozone when we have eight to ten inches of snow outside um and now you wonder probably what are they talking about because what about all these air quality alerts that we have seen over the recent weeks um you know that they have been happening on days when it's cloudy when it's cold and they say that that's only happening summertime well this is a different problem that we have in wintertime most of our problems are with particle pollution and then the problem comes because we have what we call the inversion layers um and inversion temperature in inversion layers are basically temperature inversions so what we have typically we have warm air at the surface and our air gets colder with altitude when we go up which means our warm air rises and we can ventilate and loft out the pollution and we get things well mixed around now during an inversion we have the opposite we have actually cold air at the surface with a layer of warm air above so that is like now a lid uh that traps all the pollutants at the surface doesn't let them go anywhere and all these particles that we generate from human activities from traffic from road dust all that accumulates them so just to make clear to you that we also see our quality alerts in wintertime but they are most uh most of the time they're related to particle pollution and when we have these cold pools at the surface and warm air above uh so I just wanted to make sure that uh we bring also this point across so now um I would like to finish with just making a few remarks on we don't have to just take pollution as a given we all can actively work towards protecting ourselves but also help to reduce the pollution that we have in our atmosphere first of all in order to protect ourselves we really need to stay engaged stay aware and really live smartly um limit our outdoor activities specifically on poor air quality days either on these bad days just you know stay a couch potato sometimes it might be healthy um but also we can look at the timing of different pollution so ozone typically is highest in the afternoon in the evening well if I go outdoors in the morning I just do a much better um service to my health than if I go in the afternoon or early evening just when the pollution is the highest and we also all need to understand that each of us can make a difference uh in reducing the emissions and reducing the pollution that is um benefiting our driving uh carpooling helps uh don't let your car idle don't let it sit in a parking lot and idle for 10 minutes while you're checking you know your iphone or send a text message these are all unnecessary activities that just create extra pollution um in summertime fill up gas tanks and mow your lawns in the evening and not during the day uh when the emissions get in the atmosphere when there is still plenty of sunshine to create ozone uh recycle your materials that contain solvents and where volatile organic compounds could evaporate into the air so really don't just drop your paint into a trash can really bring it to a recycle center conserve energy whenever possible I don't have to sit in winter time with a t-shirt and in summertime Mrs. Weather uh use your thermostat smartly and be also conscious about what you consume it's not just the amount of traffic that we ourselves are driving around it's also when I order something when I go and I buy now I'm not sure a pineapple that comes from somewhere all the goods have to be transported around and all this transport causes emissions and if I buy something that is coming from miles and miles and miles away I am also responsible for part of these emissions and specifically also stay aware stay informed uh know when there are days with good air quality when there are days with bad air quality there is a lot of great resources out there such as the Colorado department of public health environments the regional air quality council has a very good website um air now there is actually for air now the US US EPA air now has now the air quality awareness week coming up in May and many of the media outlets and with our forecast centers also bring the information about air quality so really be engaged stay aware and most of all also protect yourself and with that I would like to say thank you very much for listening to us this evening and Frank and myself are happy to take any questions now thank you Gabby and Frank um we do have some questions from Facebook and if folks think of more questions out there who are watching on Facebook feel free to post them and we'll see if we can get to them um the first question comes from Joe Henderson he noted an ozone non-attainment area in rural Wyoming do you happen to know the cause uh Frank you need to unmute yourself else we cannot hear you unmute myself there we are yes there's actually uh and this is uh this is a very special uh place uh this place actually has ozone problems in the winter uh and that's a very interesting phenomenon um there's a very extensive oil and gas area in the uh pine pine dale valley in in Wyoming uh it's a a classic situation where you have mountains on both sides pollution gets trapped in the winter in the uh inversion uh and there's very often long periods of persistent snow on the ground uh and we talked about sunlight uh in the winter there's less sunlight because the sun is lower in the sky uh the days are shorter but if you have snow on the ground you essentially have a mirror on the ground so the sunlight you can imagine goes through the atmosphere and it hits the ground and it goes away and it warms up the ground if there's snow on the ground it gets reflected back so the sunlight goes through the same air mass twice if that makes sense and in the case of pine dale and that's also true for the um winter basin uh they frequently violate ozone in the winter time because of the oil and gas emissions being stagnant trapped in those valleys uh and because of snow on the ground uh the sunlight is enough to make considerable amounts of ozone there so that is why they are violating the standards it's a very interesting and special it's a a keen observation uh to to see that yeah and there is actually a standing joke frank meant we also need this inversion layers there in winter time so which means that the air is really trapped in the surface but often these inversion layers are very shallow so that people say if you want to breathe fresh air jump because you only need to jump up a few meters and above it will be just fine so like frank said it's a really really interesting phenomena the snow on the ground exacerbates this because you know the sunshine warming the ground is the reason for the mixing that happens you know it's warming up the air and if that doesn't happen it it can it can be weeks where the same air is trapped in the same place without a big front going through us some sort of storm coming through fascinating uh and then we have another question here from Michael Belmont he wants to know to what extent is fracking in particular contributing to ozone do you have a sense of that my cat's joining us that's also frank believe it or not hi frank hey there you are see i think you have to be careful fracking is really on only one small part of the entire process of uh getting oil and gas out of the ground it's actually it's really only the start of of a well basically and it's only very a short time i mean i'm not sure it's maybe a few days at the most or something like that versus the majority of the emissions the majority of the impact comes really during the production phase which can go on for years and years when you basically get that oil and gas out of the ground so we often use fracking as a term to this to you know describe the entire process of natural gas but that's not quite right because fracking is really this one special process in a lifetime of the entire well and so and then in our our work actually has not been able to look into different processes uh because i mean we you know you look at at oil and gas as an entire sector and we didn't do detailed studies you don't need an aircraft to do a detailed study to understand the emissions during each step of the lifetime of a well and there is actually other works that's been done by CSU where they have really done very detailed studies on individual wells to understand the emissions from these different stages of of a well thank you and michael belmont wants to know if he says didn't the trump administration decommission a very important aircraft that was critical in sampling air particulates to combat air pollution if so can that be recommissioned have you heard about this i'm not aware of that uh the president can't really decommission a research aircraft you know i mean that's not how it works that there's other people other layers in between i'm i'm not aware of anything like that okay um maybe if he has specifics i you know i i i don't know uh there's a fleet of um you know probably somewhere around 25 or so research aircraft from different agencies uh that that that are available uh in north america uh the europeans also have fleets and they they're sometimes uh part of um that some of them are part of nasa some are part of nsf noah has a fleet of aircraft that they're using the department of energy uh has a fleet of aircraft um there are some private companies that that do air quality work uh and and europe is kind of the same so so if you know if you if there was for some reason one aircraft that wasn't flying for a while it wouldn't be the end of the world either uh you know there's we have fairly good resources uh in in that respect here in the united states that's good news uh joe henderson wants to know if if uh well how much might pollution be contributing to the increase in forest fires that we've seen there um pollution doesn't really i mean pollution doesn't increase the forest fires but of course increased forest fires will increase our pollution uh but then we get a little bit also it's still a very interesting question actually because increased pollution uh also might be linked to an increase in greenhouse gases that contribute to climate change and in a warming climate we know that the risk for more and specifically more intense wild fires is increasing which then in turn will increase our pollution but also increase greenhouse gases again so it's you know climate change and air pollution to some degree are closely interrelated because many of the sources that emit air pollutants also emit greenhouse gases that uh leads to climate change and yes there is there is strong indications and i would say to some degree it has happened already that uh with climate change we have seen more intense more devastating wild fires and this trend is only to get worse in the future if we are not able to reverse um climate change or at least stop let's see our friend Lorena Medina wants to know does rain help clean up the air near the surface to decrease ozone? Yes uh it it does to some extent uh so rain rain means the sun is not shining all right and so when it's raining it's cloudy and when it's cloudy uh you typically don't have enough sunlight to make ozone uh the other thing that rain does is it takes particulates out of the air so if you had a day with high particulates the air would feel cleaner after our rainstorm as a result of that rain also takes some of the products out of the air some of the the the end products of of chemical processing of air pollution are water soluble for example nitric nitric acid is one of the the end products of NOx and that stays in the air you know until it rains out it's very water soluble every time it rains it would completely take it out uh but the reason ozone is low on a rainy day is really the fact that there's lack of sunlight rather than uh you know that it's being washed out or anything and of course when it's raining then I go indoors so then I'm not exposing myself to air pollution anyway it's raining well this is Colorado we like to go out in the rain because it doesn't happen very often it does I find you know yeah Michael Schnatzmeier uh wonders what policies you might not be able to answer this but he wonders what policies can the Biden administration implement to address our front range ozone issues and then he wonders further is uh representative Jonah Goose aware and on it you may not know this well you know yeah well maybe you know and as I said I'm not a policy maker we are here researchers and we are also not here to make any rules and uh we are here to provide scientific facts to enable policy makers to develop the right uh response to to problems but from my understanding is there is various first of all there is a lot that the state of Colorado has to do in order to uh address our problem it's really they are they are primarily responsible for it but there is of course also a lot of uh rule making that can be done on the federal level such as the clean power plant rule that was implemented on the federal level benefits basically the entire US and every single state so I think there can be actions being taken on on the different levels um I'm not aware to I mean Jonah Goose I'm sure he's aware of the different activities in the front range he's aware of all the reports that have come out I know that he actually had recently also a meeting uh with anchor management so I think he's very engaged and seeking information but unfortunately um we don't really have any more insight in that so but as I said for us I think it is important that we communicate and the interact with stakeholders but we are not the ones who really um we are not even the ones who suggest policy making or rules uh we only provide the scientific evidence I think we probably have time for maybe two more questions here uh Melanie Smith uh asks if oil and gas production is responsible for the problem is it because of natural gas escaping from the well rather than the machinery associated with producing the oil and gas it's it's all of the above all there's a number of processes that we think are the culprits um so one is leakage from the pipelines and as I said you know we didn't have to adjust the ethane and that tells us that that is likely relatively well known in the emission inventory so we we know how much comes from just leakage uh and uh and that's you know they know what they put in and they know what comes out on the other end it's pretty easy to do these balances uh the the um um compressor stations so so in order to when the natural gas comes out of the ground it has all kinds of other stuff in it that needs to be removed in order to be able to feed it into the distribution system if you were to use it as it is it would clog up the line so that doesn't work everything that's condensable has to come out and so there are big machines that do that those machines run sometimes they run on diesel sometimes they run on natural gas but a lot of them run on diesel so it's essentially having a bunch of buses idling you know around across the area the entire time so that is one reason for emissions they also need to be fueled in such these condensates uh sometimes get moved around by trucks and those trucks will leak they get pumped from a truck into a tank or from a tank into a truck and vice versa they are being brought to um facilities that split them up into useful things that can go into a refinery or butane that can be used in uh butane lighters or whatever you know things like that all these processes are subject to leaks and and and and volatilization and so all of these things come together uh the oil and gas industry has in the last five years or so increasingly uh gone to pipelining those those condensates which helps reduce the emissions because if they are not trucked that helps quite a bit uh but you know there's the wells are in place and there's a lot of you know things that will continue to be done so there's a myriad of different places where where those those leaks happen and where those vscs get emitted and of course all of these compressors and generators and those they all emit knocks as well because they're just engines like in in a car essentially so it's a complicated system and there are lots of places where you could you know make improvements of course all that costs money and you know and it has to go through a process you know where where they are essentially forced to do that you know and and that's not an easy thing to do there there's always a political process that that has to happen before that takes place thank you and our last question comes from the great journalist local journalist Susan Moran uh she says thanks for a great presentation uh it's kind of a two-part question she wonders uh is the cus csu research you referred to that of jeff collett yeah yeah yeah that's that's jeff collett and he he really is a very good source of knowledge when you want to have the nitty gritty detail of the processing and then her other question is despite recent reduction in oil gas production overall including in weld county do you expect it to increase soon after covered and if not do you think it's dangerous to live near how close to an oil gas well well um i sure would not want to live downwind of an oil and gas well um and you know thousand feet or two thousand three thousand feet as far away as possible downwind that's that's for sure um it's really i think it's really hard to give a one distance for everything it's like you know what's the magic number uh there is not really a magic number and you know this is where very scientists don't have to give the answer that nobody likes to hear well it depends it really depends uh how clean the ball is some balls are cleaner than others um it depends on the metallurgical conditions on the winds um it depends on the number of factors but one number isn't satisfying everybody i mean if you if you live 10 miles downwind of it i say yeah that's that's probably fine right but then things have diluted enough but if it's a thousand feet two thousand feet or three thousand feet um i would not dare making an estimate like that you know um the other thing is that if i mean i would not want to live downwind of a processing facility uh you know always come and go once they are completed they're they're probably okay to live close to you know relatively close to uh but i wouldn't want to live to one that is being put in because for the first year you you know you have all the noise and all that so and that's probably worse than than than the emissions i mean you know it's it's there there's an overall impact on uh you know i i just recently got a phone call from someone that had looked us up on the internet or whatever and and they wanted to know whether they should move to eerie uh this was in the news yesterday that they just started uh putting in a couple of wells across from across the street from where there's a new neighborhood going in in in eerie uh and they were wondering that they asked me should we move there i was like you know man that that's a deep question right yeah so we talked for about half hour and uh and um and uh it's it's such a complicated thing to answer there are so many factors that go into this uh and uh and and so many factors that are individual for people that you know i mean i would personally be bothered by the noise and the light uh you know also uh that's that that's going on for a year and then you know after the well is completed that's probably okay but if there's a big pumping station or a big processing facility right next to it uh and you are downwind of it that's a whole different issue you know and and again this is uh as is personal it's everyone has a threshold for for everything and and everyone has a different threshold for chemicals too uh what we can tell you is that we made measurements in Plattville on the ground for about six weeks right straight in the summer of 2014 and uh the nighttime concentrations of some of the voc uh that are of possible health impacts they were high enough that i would not want to live there personally um and uh and that's a result of all the facilities that are surrounding that area uh you know that that's the Plattville site where where NOAA makes their measurements it's it's off of uh of uh a highway 85 uh between LaSalle and and and and greedy them and you know Plattville and LaSalle so uh you know this there are guidelines for concentrations of benzene and whatnot that you can be exposed to over long periods of time short periods of time um and you know there are there's just numbers uh you know and maybe just to add to that that actually um CDPHE the Colorado Department of Public Health and Environment they do have now a mobile van uh that was kind of an idea that was brought up as part also as a follow-up from Frappé and they have a mobile van that can measure really all these uh uh very specific vocs and also a lot of other compounds and they park it or they deploy it across the front range at crucial locations where there is maybe significant potential impact on uh human health or um you know or where there is serious complaints and they will try then to to really bring their mobile van to that to that site and to extensive measurements and really characterize if there is indeed a problem on to people or not and so I think this is a really great resource that we have in the front range and I think that that's really a really big help for uh for establishing a very safe to live and very not yeah as far as I know they are working on putting together a second one Excellent yeah well thank you both so much um you know on behalf of the city of Longmont and the city's sustainability program and the Longmont Museum I just want to thank you for all of your important work and for sharing it with us this evening it's just been terrific I also want to thank Lorraine and Medina and NCAR in general uh for working with us we're really glad of that glad for that partnership um and look forward to doing many more of these kinds of programs in the future within CARM I do want to mention that uh next week if you were planning on tuning in for our divided we stand on the future of democracy panel that has been postponed until the fall so we'll be doing that again fall our next program is two weeks from today March 4th oh no that's not March 4th that would be March 11th it's a program uh an evening of storytelling and piano music presented in collaboration or in conjunction with our current exhibition enduring impressions is an impressionism uh exhibition and an evening celebrating impressionism two weeks from today um thanks again to you both um take care be well and see you all see our audience in a couple weeks thanks for having us you save everyone and everybody for for joining us have a good evening bye thanks again