 Good afternoon, everyone. My name is Megan Larry. I am a media officer at the National Academies of Sciences, Engineering and Medicine. Thank you for joining us here today this afternoon for a webinar on the report that was just released Wednesday, titled, Airborne Platforms to Advance NASA Earth System Science Priorities. You can now download a copy of the full report and other supporting materials at www.nap.edu. And a recording of this webinar will be available on our website in the coming weeks. For those of you who are not familiar with the U.S. National Academies of Sciences, Engineering and Medicine, we are private nonprofit institutions that provide independent objective analysis and advice to the U.S. to solve complex problems and inform public policy decisions related to science, technology and medicine. For each requested study, panel members are chosen for their expertise and experience and they serve pro bono to carry out the study statement of task. The reports that result from the study represent the consensus view of the committee and they must undergo external peer review before they're released as did this report. I have a few members of the committee that wrote the report here with me today to talk about their work, but before I introduce them, I wanna go over just a few reminders about the session. Please note that the webinar is scheduled to last one hour, so we'll start off with a presentation from the committee summarizing their findings and then we'll open it up to any questions you may have afterwards. And to ask a question, you can just click the Q and A button at the bottom of your screen and type in your question and you can submit a question at any time during the presentation. All right, so now I'd like to introduce the members of the committee that wrote the report who are here with us today. Bill Brune, chair of the committee and distinguished professor of meteorology and atmospheric science at the Pennsylvania State University. Sarah Gilley, professor at Scripps Institution of Oceanography, University of California, San Diego. Jim Crawford, senior scientist for atmospheric chemistry at NASA's Langley Research Center. Ann Nolan, professor at the University of Nevada, Reno. Song Liu, Schuller-Foske, professor of Earth Sciences at Southern Methodist University. And with that, I will turn it over to Dr. Brune. Okay, thank you. So next slide, please. Okay, so what is the Earth system? This is really the focus of this study and really the focus of a lot of our research. Basically, it's everything around us. It's the trees that we see. It's just land that we see. It's the ocean, it's the water, it's the air. All those things make up this very complex system. And what we're interested in is that it's constantly changing and it's constantly changing on a variety of timescales all the way from sub-second, all the way up to millions of years. And all these are connected together. So this is a very difficult system to study. And we need to observe it in order to have any chance of really understanding what's happening. Now, these observations come from a variety of sources. And so what we're talking about today is the integrated observing system and particularly how aircraft measurements and airborne measurements fit within that context. Next slide, please. So NASA plays a major role in their system science in the United States and the world. And part of its role is essentially to have a fleet of aircraft that essentially fill that need for measurements of certain types. And so the fleet that NASA maintains is probably one of the most extensive and diversified for Earth system science anywhere in the world. And it's really important to as an element of sort of the Earth observing system. Next slide, please. Okay, so the basic science that we take and the roadmap that we're using is from essentially the Decadal Survey of Earth Science and Application from Space, which was in 2017. And this, it was aimed really at space-based observation needs. On the other hand, before it talked about the needs, it talked about the science that had to be done. And so it looked at all different areas, what needed to be measured there in order to solve complex problems. And also to look at what was happening in terms of interdisciplinary science, which is an emerging field that's been there, but it's gonna be growing in the future as we try to sort of resolve societal needs as they come up. Next slide, please. So what is the integrated observing system? It consists of several elements that are listed here and you can see them in this figure. It obviously has a space-borne observations because that's what NASA does. And it also has surface measurements. That includes remote sensing of systems and ground-based systems and ocean-based systems and even systems that look underneath the ocean surface. And the aircraft then are linked between those two, the space-based and the surface-based. And so it consists of piloted aircraft, both propeller and jet, and now increasingly even more uncrewed aircraft systems, which is shown over on the right, and then also balloons, which is shown over on the left. And so these make up a lot of the observations. In addition to that, there are laboratory studies that feed information into all aspects of these observations and then understanding them. And finally, all this is kind of put together with modeling of various sorts, where the modeling sort of is really embodies everything we know about the Earth system and also allows us to predict what'll happen as the Earth system keeps changing. And last of all, and most important of all is the people that do all of these things and make all of these things work. And we need a diverse array of people with a diverse array of skills to do this. So next slide please. Okay, so a topic of this report is really the NASA DC-8 aircraft, which was acquired in 1987. And its very first mission was to go help study and understand and test the hypothesis of chlorofluorocarbons destroying ozone in the ozone hole. It's a long range and heavy lift aircraft, which means it can go far and it can carry many people and many instruments. It has many ports and whatnot to try to, that many instruments can use. And it can fly all ranges in terms of up and down in the lower atmosphere. And so because of all these strengths, it can really address some really unique questions. So far, there've been more than 140 campaigns and the use has been evolving. So if you look over on the right, you can see for different decades, what the main uses of the DC-8 were. And you see that in the 87 to 99 in that period, that really it was a lot of surface measurements for ecology and for surface science and for water and energy. And the atmospheric composition was important and weather was important. And then in 2000 and 2009, it was mostly atmospheric composition but there were surface still and growing cryosphere. And then in 2010, 2019, you see cryosphere was dominant with atmospheric composition next to weather. So you see there's been an emergence and a change over time of which areas have used the aircraft the most but we see that they all have been involved with that. And so the picture on the left is really from a poll to poll study looking at atmospheric composition. And you can see that this aircraft can carry many, many scientists operating many, many instruments at the same time. Next slide please. So the committee was charged at sort of looking at a studying with the idea of guiding NASA in their choice of future investments in suborbital airborne facilities with a particular role on this idea of the large airborne facility such as a NASA DC-8 that has this unique combination of many, many different characteristics including long range and heavy lift and vertical profiling and other properties and being able to carry a lot of people and all those properties. And so the DC-8 of course is at the end of its useful life. Now, in addition to that is interest in how can smaller aircraft be used and how can new newly available platforms like UISs and balloons make contributions to answering these science questions that are being asked. Okay, next please. So the Academy put together a committee that has very, very diverse background, this one backgrounds and technical backgrounds. And Shuie Chen was a co-chair and then Christy Boring, Catherine Cahill, James Crawford, Dave Fahey, Sarah Gilley, Bonner Grubisick, George Komar, Eric Court, Zhang Liu, Greg McFarquhar, Walt Meyer, Charles Miller and Nolan, Biat Schmidt and Susan Houston were all members of this committee. And so with this committee, we had expertise in atmospheric chemistry, meteorology, climate science, cryosphere, land surface properties, hydrology, ecology, physical oceanography, geosciences, as well as expertise in satellite-based Earth observations in aviation and UISs in technology and instrument development, ground-based observations and modeling. Next slide, please. So the study approach was to have virtual meetings from May 2020 to March 2021. And I think everyone knows why they were all virtual. And we had information gathering workshop, which was in July of 2020 with requests for written input, which we got several different, we got input from several different people for that in summer 2020. The sessions were aligned on the three days. Along the lines of what we decided were sort of three very important discipline areas that were based on ESAS, the Decadal Survey, in different areas. And these were the ones that we thought really had used and were likely to use into the future aircraft as part of their research. And so they were surface dynamics and geological hazards and disasters, ecosystem change both on land and ocean, air quality and atmospheric chemistry, chemistry coupled to dynamics, physics and dynamics for improving weather forecasts, sea level rise in a changing climate and coastal impacts, and coupling of the water and energy cycles. So these are what we chose as disciplinary areas, representing the major, major, major components of the ESAS study upon which everything is based. Okay, next slide, please. All right, so what we did first was we took the ESAS questions, which are in the Decadal Survey Report, so 2017, and we said, okay, what needs to be measured? What variables need to be measured? And that's over on the table on the right. And then we mapped that on to questions where aircraft and airborne measurements had a major role in essentially helping to answer those questions. And so this is an example from sea level rise and coastal impacts here. We have one for each area, and so we just chose this one by random to show, but they all have essentially the same sort of mapping all the way from ESAS all the way over to sort of what the aircraft can do. And then to be responsive to our statement of task, we then asked the following questions, which questions are best addressed with large aircraft? Which ones are well suited for a combination of smaller aircraft? What about other platforms like balloons and UASs? And finally, what other benefits are there to earth system science and applications that the airborne platforms provide? And this includes things like satellite calibration and validation, instrument development, model testing, and essentially workforce training and development. Next slide, please. But we know that we have these six science areas and we recognized early on that really there's science and even emerging science that we haven't even thought of yet that's going to require interdisciplinary work and interdisciplinary research where you take expertise from different areas and you bring it together to solve a problem that's at the boundaries of these six areas that we set up. And so we're looking at collaborations across these and of course, there are many, many of these sort of interdisciplinary science that exist and we know there are many that are gonna come in the future. And so in this section here, we sort of tried to lay out two examples where large aircraft could play a role and these were just examples and not prescriptive in any way. And in all of these cases, like in many cases that we've already done, we know that there are going to be impacts on societal decision-making so that the science actually is connected to societal decisions. And so we needed this section on interdisciplinary to look to the future as well as to answer some of the science priority questions from ISIS. Okay, thank you. Thanks, Bill. I'm gonna continue from here. Next slide, please. So as Bill said, the study was built around six science areas and the committee looked at ISIS questions that arose from those where a large aircraft such as a DC-8 or airplane with DC-8 capabilities would be helpful. The study found that to meet basic disciplinary needs, large aircraft was really essential for three of the areas, atmospheric physics and dynamics for atmospheric chemistry and for the atmospheric component of coupling of the water and energy cycles. And for this, the aircraft plays a role for simultaneous observations of rapidly changing phenomena. It has a payload size and flexibility that allows large instruments to be put on an airplane to make measurements and it has the long range capability to access remote locations. For three of the areas, the committee found that a large aircraft was useful for innovative approaches to multi-instrument remote sensing and it could be envisioned to address some key questions. So this applied for ecosystem change, both for land and ocean, for surface dynamics, geological hazards and disasters and for sea level rise in a changing climate and coastal impacts. So for these areas, a large aircraft is valuable because it's able to do multi-sensor measurements and to access remote regions. And then for the interdisciplinary science that the committee looked at, an aircraft provides flexibility to accommodate and enable new approaches and needs for multi-instrument and air deployable payloads and to collect novel combinations of observations simultaneously. Next slide, please. Beyond the science questions, the committee looked at the other things that a large aircraft can do. Some of that involves instrument development. So instruments that are likely to be large and heavy that might be designed to go on a satellite, eventually it may need a large amount of power can be tested from a large aircraft with operated by the people on board. A large aircraft is also essential for testing future measurement concepts that may be tied to multi-sensor capabilities that allow new discoveries. And having a large aircraft available fosters innovative thinking for comprehensive airborne studies of global atmospheric composition, for example, and potentially for other areas in the future. And there's a real need to have an aircraft large enough to compare new instruments with legacy instruments so that we can verify that legacy instruments that are being replaced so that we understand the performance of legacy instruments relative to the new instruments that are being evaluated. Calibration and validation is an important area for NASA science and for a large aircraft and that need is expected to grow both airborne and space-based observations are needed for, well, airborne and space-based observations are used for models to constrain chemical transport and climate models to address the earth's system science questions and that's an important application. And satellite remote sensing of surface properties and phenomena requires a large aircraft with multi-sensor payloads to carry out the calibration and validation of the sensors and that's especially true for remote regions. These needs are likely to become more critical in the future as the satellite observations become more complex and require more complex satellite calibration and validation strategies. Training is a big area. Large aircraft will continue to have the benefit of allowing a large number of investigators on board to run instruments and it provides opportunities for students and early career scientists to participate in airborne missions. A large aircraft is also an effective facility for attracting training and developing a diverse workforce which will be critical for attacking rapidly advancing or for addressing advancing technologies and meeting the challenges to study our complex earth system in a changing climate. And then the other thing that report emphasizes is that there are plenty of unexpected things that happen in the earth's system. Unexpected phenomena can have detrimental effects on human health and society and on the economy and they need immediate research responses so that we can address the challenges they raise. So the example of the Antarctic ozone hole is a good one where the fact that a large aircraft was available and the instruments were available meant that the science community was able to rapidly respond and carry out observations to address and figure out how to mitigate that problem. Next slide please. So the recommendations that come from this are that NASA should acquire, maintain and operate a large aircraft as part of its aircraft fleet in order to address priority questions developed for the 2017 earth science and applications from space to CATL survey and to support satellite calibration and validation computer model testing, instrument development and workforce training and development. Next slide please. In addition, a second recommendation is to meet NASA objectives. A new large aircraft must have characteristics that are comparable to or better than those of the DC-8 in terms of payload capacity, altitude and distance ranges, instrument sampling, port versatility, instrument integration and durability. Next slide please. Now what that means requires a little thought and the committee has provided a list of essential characteristics and desired values of some of the characteristics for a large aircraft. These characteristics are not meant to be prescriptive but they provide guidance for selecting a new large aircraft and the committee recognizes that optimizing performance specifications of a new large aircraft may involve some trade-offs. But the basic combination of these characteristics is essential. So that includes having an instrument payload weight of 14,000 kilograms or more, flight duration on the order of 12 hours and range of 10,000 kilometers to reach remote regions of the world an altitude ceiling of at least 12 and a half kilometers and the capability to profile vertically from the planetary boundary layer to the altitude ceiling. In-flight seating for on the order of 42 or more researchers in addition to the crew, instrument payload integration and operation flexibility, durability, precision autopiloting to allow exact repeats of the same ground tracks for example and in-flight satellite communication links to operations on the ground. Next slide please. A large aircraft is just part of the NASA fleet but it's only one key contributor to a very diverse array of airborne platforms that are needed to address earth system science objectives. Airborne platforms with diverse specifications of payload, range, altitude, onboard pilot and operational flexibility form a complimentary fleet currently that meets a wide range of mission objectives often in collaboration with airborne platforms and the fleets of other research agencies, private organizations and other countries. A substantial amount of past airborne science has used more than one airborne platform together in research studies often deploying different types of aircraft to perform different roles and NASA often contributes its platforms including the DC-8 in collaborative efforts with other US agencies, other countries, universities and private organizations. So these efforts will become more essential as earth system science questions become more interdisciplinary and more complex and a new large aircraft capability and NASA is expected to continue to play an essential and enabling role in many of these interdisciplinary efforts. Airborne science today is accomplished using many aircraft that are smaller than a DC-8 for several reasons listed on this slide including the payloads are small, rapid deployment is needed, the observing requirements for some combinations of remote sensing instruments may require different aircraft and it may be desirable to have them in different operations and the DC-8 has a high operating costs that exceed some available budgets. So it's part of a broad portfolio. Next slide please. And UASs are also an important part of this they're being deployed for a wide range of in situ and remote sensing applications. As sensors continue to get smaller and lighter the role of UASs in earth system science research is expected to expand. Large helium filled balloons are also important. They're currently the only way to sample the middle stratosphere in situ. And for some stratospheric wind conditions they can stay aloft over a specific region for many days to allow in situ or remote sensing. So while there are promising developments in high altitude long duration UASs and in steerable balloons these technologies may not advance quickly enough to contribute significantly to earth system science research within the next decade. Next slide please. That leads to the recommendation that NASA should continue operating a diverse array of airborne platforms in addition to a large aircraft as part of the broader government university and commercial fleet in order to meet the evolving airborne needs for advancing earth system science research. Next slide please. Then as Bill mentioned earlier an important part of the ESAS 2017 an important part of this study was to look at integrating themes and the role of, in this case in the role of aircraft to address some of these interdisciplinary science topics. The report covers two of the two examples wildfires which are shown on this slide and extreme precipitation and flooding. In the case of wildfires climate change combined with weather past fire suppression efforts and other factors have led to hotter, more damaging wildfires in recent years longer fire seasons and high price tags. And this has impacts on human health through direct exposure. It has impacts on infrastructure. And it leads to knock on effects for further hazards for example, resulting from say landslides in burned areas after heavy precipitation. So rapid earth system science changes like this highlight the need for interdisciplinary research and for simultaneous measurements. Next slide please. And that leads to a recommendation that NASA should continue to solicit large aircraft requests that span the breadth of NASA earth system science especially encouraging those for interdisciplinary science across the interfaces of earth system components with integrated multi-instrument payloads and novel strategies for remote sensing and in situ observations. Earth system science is increasingly interdisciplinary and the committee felt that NASA should proactively seek proposals for innovative approaches for using a large aircraft to accomplish interdisciplinary and surface remote sensing in addition to supporting the new disciplinary research. And that by doing this NASA will increase the impact that a large aircraft can have on achieving NASA's earth system science research goals. Next slide please. Training outreach and workforce development is an important part of what an aircraft can do. Future advances in NASA earth system science research depend on the continual emergence growth of early career scientists to develop new measurement concepts to make measurements and eventually to take over field studies themselves taking leadership roles. So a large aircraft is a really important facility for attracting training and developing this diverse workforce. And it also plays a role in engaging the public because it provides the space to accommodate additional passengers beyond the core scientists and crew needed to carry out the mission. Next slide please. So recommendations that come from this are that NASA is encouraged to build on the training and outreach opportunities that has established using the DC-8 and use a future large aircraft to expand its efforts to attract, develop and train the next generation workforce with particular emphasis on diversity, equity and inclusion to foster capacity to conduct international earth system science research and to inform the public. And NASA is encouraged to continue building on its use of the large aircraft capacity to enable scientists with next generation measurement concepts and especially early career scientists to become active participants in earth system science research even beyond airborne science research. Next slide please. So some concluding thoughts. Airborne observations have enabled exciting and transformative science for the past three decades. A large aircraft is expected to remain essential to NASA's earth system science research to fulfill the vision of ESAS to embrace emerging science and technology and train future generations of scientists. A new large aircraft will provide capacity to address increasingly complex science questions, enable innovative observations using multiple platforms and multiple instruments and address growing societal needs for decision making in a rapid changing climate with rising seas in the coming decades. Next slide please. The study of course would not have been possible without an enormous number of people including the committee members and National Academy staff. The report review monitors, whose names are on the screen and report reviewers kept this report honest and their health was absolutely invaluable. And of course we thank the study sponsor who's NASA. And that's the end of our presentation. We're gonna take questions now. We thank you for attending and we welcome questions, which... Yes, thank you all for that wonderful presentation. Sarah said, so we're gonna open it up to questions now. If you'd like to ask a question again, you can do so just by clicking Q&A at the bottom of your screen and typing in your question. So the first one that I wanna start us off with is for those of us who are not working at this field at the moment, what is earth systems research and what can we learn from it? Do you wanna take this one? Thanks, could you repeat the question please? Yeah, of course. So just for those of us in the audience who do not work in this field, what is earth systems research and why is it important and what do we learn from it? Okay, so earth system, let me just say first what earth systems science is and then I'll talk about what we learned from earth system research. So I would say traditionally years ago, decades ago, we used to think of the earth components as individual disciplines and oftentimes we would learn and our research would focus on a particular discipline. So back in the day, oceanographers would only look at the ocean atmospheric scientists, would only look at the atmosphere, terrestrial scientists, hydrologists like myself would only look at the water as, and now we've realized it's a whole system. These things are fully coupled. So for instance, when I think about water, where does it come from? Well, it depends on where you start. It could start in the ocean and then you have the evaporation into the atmosphere, clouds forming and moving and atmospheric dynamics and circulation and precipitation with the water landing on the land surface being used by vegetation, moving into soil moisture into deep subsurface for groundwater and flowing into our rivers and so on and being connected to people and all the ecosystems connected. So this is the earth system. It's all of these systems working together with people in all of this. And so our research has really transitioned from disciplinary to coupled systems. And that's one of the reasons why my part of this report was called the coupled water and energy cycles. And of course, these are all coupled to other cycles like the carbon cycle, for instance. So our next question is, to what extent did your committee consider opportunities for these airframe platforms to advance or system research that's sponsored by other federal agencies, NSF, for example, the National Science Foundation? Do you wanna take that one? Do you call me on that one, Bill? Yes. Yeah, so one thing that I would acknowledge in this is that the report states pretty clearly that the NASA aircraft are very often used in larger efforts, along with interagency aircraft. And so many times you see multiple aircraft working on a problem. And so in the sense that those aircraft all come together to tackle the same problems that's covered in the report. Great, thank you. So I'm hoping that you can explain for me how the DC-8, excuse me, is used today in climate research, climate change research. And how do you think that your recommendation to continue using another large aircraft may impact climate change research? So Sarah, do you want to try that? I can start. The report outlines a very broad range of uses for the DC-8 for climate change research. As a table that Bill Brunsch showed indicated that usage has changed over time in the most recent decade. There's been quite a bit of work in the cryosphere, but that's probably changed now again. And a lot of the work with the DC-8 has been atmospheric research. We expect that that will continue to change in the future as new science emerges. I can add a little bit to that. And again, it's gonna be anecdotal because we each have different disciplines. And as Sarah noted, the table in each of the disciplinary chapters of the report all refer to climate-related ESAS questions that we're each trying to address. But a good example of how climate research benefits from large platform goes back to the fire example that Sarah mentioned. For instance, when we flew recently looking at the fire activity in the atmosphere as part of FireXAQ, the atmospheric portion of that science was complimented by an instrument on board, which could look at the fire radiative power, the energetics of the fire. And on a smaller aircraft, we could only look at the atmospheric part of the question. But by being able to combine an instrument that looks at the fire behavior on the ground and then combine that with atmospheric measurements of what's coming out of the fire, you begin to see the interdisciplinary aspect of what a large platform can enable as an example. I'll add one component to that. And that's the fact that the DC-8 can carry a lot of people. And one of the most important things for climate change research is workforce development. Because the scientists who are going to be addressing the current and future challenges and need to be trained and need to have that experience of being able to operate instruments in a team environment on board a large aircraft. So it has to have large capacity for lots of students and postdocs and so on. Another component of the climate change research is the fact that we are seeing more really unexpected and extreme events. And so we need to be able to deploy a large capacity flying laboratories such as the DC-8 in a way that we can really capture that sort of extreme behavior. For instance, what Jim was saying about wildfire and atmospheric chemistry and dynamics. Our next question from the audience is a number of replacement aircraft were suggested in the report. And the audience is wondering, do these aircraft have the same capabilities as the DC-8 when it comes to flying within hurricanes or maybe similar challenging weather conditions where you need, you know, on-site observations? What would your response be to that? So Jim. So I want to emphasize up front that this group was not charged with actually identifying a replacement aircraft. But we did refer to a study that NASA commissioned to look into possible future NASA aircraft. And so if you follow the reference in the document, you'll find that there are more than a few possible candidates that would satisfy the requirements of looking like and acting like a DC-8 or better. So I would just refer people to the Ozurowski et al. reference as some material that can help you look into those possibilities. But that explicitly was not in our statement of past. It was mostly to say, what do we need to do the science? And that that was the key. And how large aircraft, smaller aircraft, new development technologies and UASs and balloons will work into that. And then what are the other benefits? Those are really the four main components of our statement of task. And I think this question is in a similar vein. But did you have a recommendation as to the expected or recommended life span for a future large aircraft? No, once again, that's not really within our statement of task. Our statement of task is, what is it gonna take to do the science that's here and that's evolving through the vision of ESAS? That was really sort of the time scale that we were tasked to look at in particular. Thank you. So one thing I wanna ask you about as you were thinking about creating capacity for the unexpected, as you said in the report, in airborne platforms research, what kinds of scenarios were you thinking about or imagining as a committee research that we might not know that we need now, but that might be essential in the future. Jim. I would just add an example there. So looking at the history of the DC-8 helps with this question of unexpected. Ice bridge was a major user of the aircraft in the last decade and was not expected. And so the idea that we had a plane on hand that could satisfy all the other disciplines and shoulder the burden of those bridging observations that went really beyond what the current satellite does and opened the door to a lot of great research on the crowd sphere is a great example of unanticipated use of an aircraft. So if for some reason the large aircraft platform that your report recommends in NASA go with were to be unavailable. So if we didn't have it for research, what do you think the impact would be on the Decadal Survey science questions that you considered? So, John or Jim or Ann, Sarah, you wanna take the first cut, Ann, please. I think one of the impacts from the perspective in a coupled water and energy cycle part of the report is we identified that a DC-8-like aircraft that could support the SBG, the surface biology and geology mission development calibration and validation. If we didn't have that capacity for a large heavy lift, long duration aircraft, we would I think really miss out on the ability to do CalVal in places like the polar regions which are the fastest changing, you know, due to climate change and that has really important bearing. So. John? Yeah, I want to mention that, you know, even for the geological hazard or surface dynamics, we, in the past demonstrate experiences, we used the small aircraft. So that's the preference of Decadal, one of the important thing is to rapid development and we can critically use the radar data during our weather conditions. But however, if you don't, we currently all the small aircraft, you can only put host one sensor, one band of sensors. So the early system, like to say, how about we put a model of radar data for different applications, for different purpose for them both, we got the digital activation model to look at the data, to look at the definition of dynamics. Without a large aircraft, we cannot accommodate multiple radar sensors alone without mentioning the inclusion of optical data and other data on the same plane. Keep adding to this, to this discussion. And it's always best that we each speak from our discipline. That's why we brought together so many great scientists from different areas. But, you know, you look at the DC-8 as exists and our field fills the plane and continues to want more. And so adding that fire-rated power measurement on the DC-8 would not be possible with any other aircraft. So we wouldn't be able to do atmosphere and the fire itself. And also notice that when we do our campaigns, we're looking at trace gases, aerosols, radiation budget, weather. It really is already interdisciplinary because so many of the things that we're doing rely on us looking at multiple aspects of what's going on in the atmosphere. And so a smaller aircraft would mean a step backwards, really, in terms of the breadth with which we could look at various phenomena with simultaneous measurements. Sarah, do you have something you would like to add? Well, I think I just emphasized the... For work, say, on sea level rise or... And there's a lot of uncertainty about what the next approaches should be. And having a large aircraft provides ways to do unexpected things or to tackle emerging science. So we may not know exactly what we get from it, but there's a lot of confidence that having a large aircraft will allow us to do science that we haven't foreseen yet. And then last of all, there's this issue of capacity to essentially tackle unexpected events that are critical in terms of society, economics, and whatnot. And so without that, as Sarah said, the ozone hole that would have been delayed if that capability hadn't have been there. And that means that really the recovery of the ozone hole would have been delayed and there would have been societal issues associated with that. So having that ability to respond fairly quickly and really resolve questions in your system like this is really important. Great, thank you all. Our next question is, can you give me some examples of the type of science that large aircraft can do that persistent low earth orbit satellites cannot? Well, I think everyone has examples. Who would like to go first? And do you want to go first? Zhang has his hand up. Oh, sorry. Go ahead. Go ahead, Zhang. OK, I think one of the things, for example, all done for the geological hazards. So while the primary use of remote sensing data to look at the surface depth measure associated with the various geological processes, understanding the mechanism, and even sometimes the use of predictive capacity. So all the satellites are actually all waiting for north to south. And then there's one component. If the ground movement is moving north to south, the satellite really is not a sensitive. So on the other hand, if you fly an aircraft east to west, you can be very sensitive to that component of the world's definition. And there are some other properties, too. So this is really the flexible geometry of our bosons that really complements and actually enhances the characterization of the geological hazards and mirroring the characteristics from different viewing geometry and different timescale. OK, so I did want to add something about this multi-scale component. So Leo, low Earth orbit satellites are great. And we want that because it does provide us with high spatial resolution. And at the same time, multi-scale information is really important and critical for understanding fundamental scaling relationships and being able to characterize the process at the scale of the process, which is something that you can do with a more agile aircraft. And that's probably going to require maybe multiple aircrafts or aircraft flying at different elevations and stacking them or a variety of ways that we can do that, perhaps in conjunction with a low Earth orbit satellite. So we want to be able to represent the processes, in my case, in the water and energy cycles at the scale of the process. And the scale of observation from a satellite is fixed and not necessarily representative of the scale, the temporal or spatial scale of the process that's occurring. And that's especially important when you have events such as flooding going on. Or even longer-term extreme events like drought, where you really need to kind of understand in different ways how the drought is occurring. So I'll stop there. I think somebody else had a comment on this. Yeah, this is Jim. I'll actually build on what Ann's saying because I think it's very important. And so I was going back to read the question to make sure I understood it. And I want to challenge the basis for the question all together, which is that satellites and aircraft are meant to substitute for each other. And when you look in the document and look into the deeper discussion about observing systems, you begin to see that each plays a role and that each looks at something different. From space, you see, at least for atmospheric chemistry, you can count on my fingers how many things you can see. But from the aircraft, we measure hundreds of things. And also when you're looking through the atmosphere, you're measuring the total amount of what's in the atmosphere. Vertical profile information is very difficult to achieve, whereas aircraft can profile institute and provide great information. And then at the ground, it's a very different story. When you're trying to regulate something like air quality, only a ground measurement can truly diagnose what someone's experience on the ground level. And everything else is trying to help the satellite provide information relevant to that perspective. And so you really need to ask yourself how aircraft contribute to the different ways that we look at things and flesh out the picture scientifically. I'll just add that one of the things aircraft do is let us deploy instruments, which we're not able to do from low Earth satellites. So sensors that are dropped into the ocean or dropped through the atmosphere are really important from aircraft. Thank you all. Our next question is also about the size of the aircraft. Could emphasis on making smaller instruments lead to more use of smaller aircraft? Do you think that large aircraft encourage large instruments? I don't. And here's why. There's a reason the DCA is called a flying laboratory. Most of these instruments are moving directly from a lab onto the plane. These development time scales to make things smaller are for things that you want to measure in perpetuity in a monitoring sense. But each time we fly a campaign, there are new instruments. There are new capabilities. There are things that we can't wait for in terms of making measurements in the atmosphere. That's what the large aircraft gives you the chance to do is to bring science quality measurements to the atmosphere on very short time scales. It literally is coming from the laboratory of people who are developing and have developed new technologies in terms of atmospheric measurements. But they aren't necessarily engineers that have experience with packaging it for small platforms and whatnot initially. And so this is a perfect place, as Jim says, a flying laboratory to really try out these new concepts and then move forward from there. Thank you. Did your panel consider procurement, outfitting, and operational costs for a DC-8 replacement? I'll answer that one. And this was not part of our statement of task. We were essentially doing the science to what type of platform is needed to accomplish the science. And then what are the possible other smaller aircraft and what balloons and UASs can do and then what else might happen. And that was really what we were tasked to do and not with any of this other. Great. Thank you for clarifying. Our next question. The audience says, in my experience, the NASA DC-8 has limitations with its available number of mid-year viewing ports relative to other NASA aircraft like the P-3. Was there any consideration toward recommending improved capabilities for hosting additional mid-year-style remote sensing instruments and a future NASA large aircraft? Okay. Anyone want to take that? I will. I'll just say we discussed it and it was certainly something that came up, particularly in the ice bridge conversations. Bill, did this make it into the report? I don't recall exactly. So, if you look at our recommendation on number two, which is the recommendation on what should the aircraft have, what we say in there explicitly is that we need this combination, unique combination of various characteristics, but really some of what is going to be necessary in the future isn't prescribed yet and needs to be prescribed is what do we think when they put together and think about what kind of aircraft, when they put that together, they need to be thinking about where are the uses going to be and this will help dictate where we go forward in the future, when they make the decisions to move the aircraft and choose an aircraft and then retrofit it for the science. And so that wasn't something that we prescribed nor should we have prescribed in this report, but it is something that we left the possibility wide open. It says, yeah, as things emerge, pay attention to it, please. Thank you. So it looks like we have time for about two more questions. The first, could you elaborate more on your recommendation about training and engaging the next generation of researchers and airborne missions? So what kinds of workhorse changes may we anticipate in earth systems research and how do you think a large aircraft best meets these goals? Jim or Ann? One of the things that I think the report emphasizes is that the DC has already been playing this role. I was a graduate student on the DC in 1991. So this idea that there's a new thing that the DC is going to do is really more about making that better and trying to ensure that science teams include more and more involvement from young scientists who are going to become part of the workforce. And so from my perspective, over the years, things that have changed are that we're more connected. And so we've opened up new roles for young people on these field campaigns, not just being graduate students on the plane making measurements, but now casting on the ground. More and more satellite data is used to guide the aircraft and having graduate students involved in that process is very important. And including graduate students in the field who are just trying to help us gauge what the data is telling us. You don't want to spend a month in the atmosphere flying an aircraft to do something and come back and realize that you didn't get what you wanted. And so monitoring mission success along the way is an important thing to do and data scrutiny, opportunities to present in the field are all becoming more and more prevalent on these campaigns and these DCA campaigns when you have 100, 150 people in the field become great vehicles for not only exercising young people, but exposing them to the community and giving them a face and a voice amongst those of us who are going to be, you know, helping them out in the future. Yeah, I think that mentoring component has been and will be even more important and the idea that you can have, you know, a large number of people involved in DCA, on the DCA means that you're not alone. You're, you know, if you've got questions, you can ask. And so these early career scientists, whether they're undergraduates, grad students, postdocs or early career researchers, they have people that they can work with directly. And the other component here is, you know, we did indicate that this is an opportunity for a more diverse, inclusive way to get underrepresented groups involved in all kinds of science in interdisciplinary or system science. And so we see this platform as also a way to increase the diversity of our colleagues. Thank you all. And sorry, go ahead. Oh, I think I just want to add it. I think, you know, a lot of the most of the data of graduate students can grab here and there about putting them into the aircraft and let them do the designing and get the real time data and look at the anomalies. And I think that's a different experience that will inspire them to follow their future work. I think that will definitely increase our, you know, the potential that continue with the most of the field. I think that will be a tremendous experience for them. Fantastic. All right. Well, as we wrap up here today and finish up our conversation, I just have one last question. As you released your report to the public this week and as you continue disseminating your findings and your recommendations as a committee, what are you most hoping that the people who use these NASA Airborne platforms or the people who use the data that they gather, what are you hoping that they most take away from your report? Jim. I would just emphasize the scientific discourse that took place both in the Decadal Survey and the report, reminding our communities to continue to put their ideas to the agency, to show them the ways the planes can be used to our advantage and to continue to make sure that the fleet is well used and very busy in terms of the science that we want to pursue. I'll add that. I hope that the readers of this report will understand the value of the range of airborne science platforms that are available and we hope more will be available and that the DCA, this DCA-like platform has a really important role in the whole suite of platforms. But that airborne science is a really, really important component for all of NASA research. And I'll just maybe finish with this by saying we also hope that it inspires scientists, early career scientists, existing scientists to sort of really be innovative in thinking about how can I really do a great job of not only my disciplinary research but connecting to do interdisciplinary work as well. And I think that inspiration for new ideas and new approaches to get science data that's going to help us make decidable decisions is really important. Wonderful. Well, thank you all so much for your presentation today and for taking questions as well as for your work and your report, of course. So once we exit this webinar, just a reminder to our audience that you'll be redirected to our report page. So with that, thank you again for participating.