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      3Q: Why Europe is so vulnerable to heat waves

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      This year saw high-temperature records shattered across much of Europe, as crops withered in the fields due to widespread drought. Is this a harbinger of things to come as the Earth’s climate steadily warms up?

      Elfatih Eltahir, MIT professor of civil and environmental engineering and H. M. King Bhumibol Professor of Hydrology and Climate, and former doctoral student Alexandre Tuel PhD ’20 recently published a piece in the Bulletin of the Atomic Scientists describing how their research helps explain this anomalous European weather. The findings are based in part on analyses described in their book “Future Climate of the Mediterranean and Europe,” published earlier this year. MIT News asked the two authors to describe the dynamics behind these extreme weather events.

      Q: Was the European heat wave this summer anticipated based on existing climate models?

      Eltahir: Climate models project increasingly dry summers over Europe. This is especially true for the second half of the 21st century, and for southern Europe. Extreme dryness is often associated with hot conditions and heat waves, since any reduction in evaporation heats the soil and the air above it. In general, models agree in making such projections about European summers. However, understanding the physical mechanisms responsible for these projections is an active area of research.

      The same models that project dry summers over southern Europe also project dry winters over the neighboring Mediterranean Sea. In fact, the Mediterranean Sea stands out as one of the most significantly impacted regions — a literal “hot spot” — for winter droughts triggered by climate change. Again, until recently, the association between the projections of summer dryness over Europe and dry winters over the Mediterranean was not understood.

      In recent MIT doctoral research, carried out in the Department of Civil and Environmental Engineering, a hypothesis was developed to explain why the Mediterranean stands out as a hot spot for winter droughts under climate change. Further, the same theory offers a mechanistic understanding that connects the projections of dry summers over southern Europe and dry winters over the Mediterranean.

      What is exciting about the observed climate over Europe last summer is the fact that the observed drought started and developed with spatial and temporal patterns that are consistent with our proposed theory, and in particular the connection to the dry conditions observed over the Mediterranean during the previous winter.

      Q: What is it about the area around the Mediterranean basin that produces such unusual weather extremes?

      Eltahir: Multiple factors come together to cause extreme heat waves such as the one that Europe has experienced this summer, as well as previously, in 2003, 2015, 2018, 2019, and 2020. Among these, however, mutual influences between atmospheric dynamics and surface conditions, known as land-atmosphere feedbacks, seem to play a very important role.

      In the current climate, southern Europe is located in the transition zone between the dry subtropics (the Sahara Desert in North Africa) and the relatively wet midlatitudes (with a climate similar to that of the Pacific Northwest). High summertime temperatures tend to make the precipitation that falls to the ground evaporate quickly, and as a consequence soil moisture during summer is very dependent on springtime precipitation. A dry spring in Europe (such as the 2022 one) causes dry soils in late spring and early summer. This lack of surface water in turn limits surface evaporation during summer. Two important consequences follow: First, incoming radiative energy from the sun preferentially goes into increasing air temperature rather than evaporating water; and second, the inflow of water into air layers near the surface decreases, which makes the air drier and precipitation less likely. Combined, these two influences increase the likelihood of heat waves and droughts.

      Tuel: Through land-atmosphere feedbacks, dry springs provide a favorable environment for persistent warm and dry summers but are of course not enough to directly cause heat waves. A spark is required to ignite the fuel. In Europe and elsewhere, this spark is provided by large-scale atmospheric dynamics. If an anticyclone sets over an area with very dry soils, surface temperature can quickly shoot up as land-atmosphere feedbacks come into play, developing into a heat wave that can persist for weeks.

      The sensitivity to springtime precipitation makes southern Europe and the Mediterranean particularly prone to persistent summer heat waves. This will play an increasingly important role in the future, as spring precipitation is expected to decline, making scorching summers even more likely in this corner of the world. The decline in spring precipitation, which originates as an anomalously dry winter around the Mediterranean, is very robust across climate projections. Southern Europe and the Mediterranean really stand out from most other land areas, where precipitation will on average increase with global warming.

      In our work, we showed that this Mediterranean winter decline was driven by two independent factors: on the one hand, trends in the large-scale circulation, notably stationary atmospheric waves, and on the other hand, reduced warming of the Mediterranean Sea relative to the surrounding continents — a well-known feature of global warming. Both factors lead to increased surface air pressure and reduced precipitation over the Mediterranean and Southern Europe.

      Q: What can we expect over the coming decades in terms of the frequency and severity of these kinds of droughts, floods, and other extremes in European weather?

      Tuel: Climate models have long shown that the frequency and intensity of heat waves was bound to increase as the global climate warms, and Europe is no exception. The reason is simple: As the global temperature rises, the temperature distribution shifts toward higher values, and heat waves become more intense and more frequent. Southern Europe and the Mediterranean, however, will be hit particularly hard. The reason for this is related to the land-atmosphere feedbacks we just discussed. Winter precipitation over the Mediterranean and spring precipitation over southern Europe will decline significantly, which will lead to a decrease in early summer soil moisture over southern Europe and will push average summer temperatures even higher; the region will become a true climate change hot spot. In that sense, 2022 may really be a taste of the future. The succession of recent heat waves in Europe, however, suggests that things may be going faster than climate model projections imply. Decadal variability or badly understood trends in large-scale atmospheric dynamics may play a role here, though that is still debated. Another possibility is that climate models tend to underestimate the magnitude of land-atmosphere feedbacks and downplay the influence of dry soil moisture anomalies on summertime weather.

      Potential trends in floods are more difficult to assess because floods result from a multiplicity of factors, like extreme precipitation, soil moisture levels, or land cover. Extreme precipitation is generally expected to increase in most regions, but very high uncertainties remain, notably because extreme precipitation is highly dependent on atmospheric dynamics about which models do not always agree. What is almost certain is that with warming, the water content of the atmosphere increases (following a law of thermodynamics known as the Clausius-Clapeyron relationship). Thus, if the dynamics are favorable to precipitation, a lot more of it may fall in a warmer climate. Last year’s floods in Germany, for example, were triggered by unprecedented heavy rainfall which climate change made more likely. More

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      Small eddies play a big role in feeding ocean microbes

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      Subtropical gyres are enormous rotating ocean currents that generate sustained circulations in the Earth’s subtropical regions just to the north and south of the equator. These gyres are slow-moving whirlpools that circulate within massive basins around the world, gathering up nutrients, organisms, and sometimes trash, as the currents rotate from coast to coast.

      For years, oceanographers have puzzled over conflicting observations within subtropical gyres. At the surface, these massive currents appear to host healthy populations of phytoplankton — microbes that feed the rest of the ocean food chain and are responsible for sucking up a significant portion of the atmosphere’s carbon dioxide.

      But judging from what scientists know about the dynamics of gyres, they estimated the currents themselves wouldn’t be able to maintain enough nutrients to sustain the phytoplankton they were seeing. How, then, were the microbes able to thrive?

      Now, MIT researchers have found that phytoplankton may receive deliveries of nutrients from outside the gyres, and that the delivery vehicle is in the form of eddies — much smaller currents that swirl at the edges of a gyre. These eddies pull nutrients in from high-nutrient equatorial regions and push them into the center of a gyre, where the nutrients are then taken up by other currents and pumped to the surface to feed phytoplankton.

      Ocean eddies, the team found, appear to be an important source of nutrients in subtropical gyres. Their replenishing effect, which the researchers call a “nutrient relay,” helps maintain populations of phytoplankton, which play a central role in the ocean’s ability to sequester carbon from the atmosphere. While climate models tend to project a decline in the ocean’s ability to sequester carbon over the coming decades, this “nutrient relay” could help sustain carbon storage over the subtropical oceans.

      “There’s a lot of uncertainty about how the carbon cycle of the ocean will evolve as climate continues to change, ” says Mukund Gupta, a postdoc at Caltech who led the study as a graduate student at MIT. “As our paper shows, getting the carbon distribution right is not straightforward, and depends on understanding the role of eddies and other fine-scale motions in the ocean.”

      Gupta and his colleagues report their findings this week in the Proceedings of the National Academy of Sciences. The study’s co-authors are Jonathan Lauderdale, Oliver Jahn, Christopher Hill, Stephanie Dutkiewicz, and Michael Follows at MIT, and Richard Williams at the University of Liverpool.

      A snowy puzzle

      A cross-section of an ocean gyre resembles a stack of nesting bowls that is stratified by density: Warmer, lighter layers lie at the surface, while colder, denser waters make up deeper layers. Phytoplankton live within the ocean’s top sunlit layers, where the microbes require sunlight, warm temperatures, and nutrients to grow.

      When phytoplankton die, they sink through the ocean’s layers as “marine snow.” Some of this snow releases nutrients back into the current, where they are pumped back up to feed new microbes. The rest of the snow sinks out of the gyre, down to the deepest layers of the ocean. The deeper the snow sinks, the more difficult it is for it to be pumped back to the surface. The snow is then trapped, or sequestered, along with any unreleased carbon and nutrients.

      Oceanographers thought that the main source of nutrients in subtropical gyres came from recirculating marine snow. But as a portion of this snow inevitably sinks to the bottom, there must be another source of nutrients to explain the healthy populations of phytoplankton at the surface. Exactly what that source is “has left the oceanography community a little puzzled for some time,” Gupta says.

      Swirls at the edge

      In their new study, the team sought to simulate a subtropical gyre to see what other dynamics may be at work. They focused on the North Pacific gyre, one of the Earth’s five major gyres, which circulates over most of the North Pacific Ocean, and spans more than 20 million square kilometers. 

      The team started with the MITgcm, a general circulation model that simulates the physical circulation patterns in the atmosphere and oceans. To reproduce the North Pacific gyre’s dynamics as realistically as possible, the team used an MITgcm algorithm, previously developed at NASA and MIT, which tunes the model to match actual observations of the ocean, such as ocean currents recorded by satellites, and temperature and salinity measurements taken by ships and drifters.  

      “We use a simulation of the physical ocean that is as realistic as we can get, given the machinery of the model and the available observations,” Lauderdale says.

      Play video

      An animation of the North Pacific Ocean shows phosphate nutrient concentrations at 500 meters below the ocean surface. The swirls represent small eddies transporting phosphate from the nutrient-rich equator (lighter colors), northward toward the nutrient-depleted subtropics (darker colors). This nutrient relay mechanism helps sustain biological activity and carbon sequestration in the subtropical ocean. Credit: Oliver Jahn

      The realistic model captured finer details, at a resolution of less than 20 kilometers per pixel, compared to other models that have a more limited resolution. The team combined the simulation of the ocean’s physical behavior with the Darwin model — a simulation of microbe communities such as phytoplankton, and how they grow and evolve with ocean conditions.

      The team ran the combined simulation of the North Pacific gyre over a decade, and created animations to visualize the pattern of currents and the nutrients they carried, in and around the gyre. What emerged were small eddies that ran along the edges of the enormous gyre and appeared to be rich in nutrients.

      “We were picking up on little eddy motions, basically like weather systems in the ocean,” Lauderdale says. “These eddies were carrying packets of high-nutrient waters, from the equator, north into the center of the gyre and downwards along the sides of the bowls. We wondered if these eddy transfers made an important delivery mechanism.”

      Surprisingly, the nutrients first move deeper, away from the sunlight, before being returned upwards where the phytoplankton live. The team found that ocean eddies could supply up to 50 percent of the nutrients in subtropical gyres.

      “That is very significant,” Gupta says. “The vertical process that recycles nutrients from marine snow is only half the story. The other half is the replenishing effect of these eddies. As subtropical gyres contribute a significant part of the world’s oceans, we think this nutrient relay is of global importance.”

      This research was supported, in part, by the Simons Foundation and NASA. More

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      Divorce is more common in albatross couples with shy males, study finds

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      The wandering albatross is the poster bird for avian monogamy. The graceful glider is known to mate for life, partnering up with the same bird to breed, season after season, between long flights at sea.

      But on rare occasions, an albatross pair will “divorce” — a term ornithologists use for instances when one partner leaves the pair for another mate while the other partner remains in the flock. Divorce rates vary widely across the avian world, and the divorce rate for wandering albatrosses is relatively low.

      Nevertheless, the giant drifters can split up. Scientists at MIT and the Woods Hole Oceanographic Institution (WHOI) have found that, at least for one particular population of wandering albatross, whether a pair will divorce boils down to one important factor: personality. 

      In a study appearing today in the journal Biology Letters, the team reports that an albatross couple’s chance of divorce is highly influenced by the male partner’s “boldness.” The bolder and more aggressive the male, the more likely the pair is to stay together. The shyer the male, the higher the chance that the pair will divorce.

      The researchers say their study is the first to link personality and divorce in a wild animal species.

      “We thought that bold males, being more aggressive, would be more likely to divorce, because they would be more likely to take the risk of switching partners to improve future reproductive outcomes,” says study senior author Stephanie Jenouvrier, an associate scientist and seabird ecologist in WHOI’s FLEDGE Lab. “Instead we find the shy divorce more because they are more likely to be forced to divorce by a more competitive intruder. We expect personality may impact divorce rates in many species, but in different ways.”

      Lead author Ruijiao Sun, a graduate student in the MIT-WHOI Joint Program and MIT’s Department of Earth, Atmospheric and Planetary Sciences, says that this new evidence of a link between personality and divorce in the wandering albatross may help scientists predict the resilience of the population.

      “The wandering albatross is a vulnerable species,” Sun says. “Understanding the effect of personality on divorce is important because it can help researchers predict the consequences for population dynamics, and implement conservation efforts.”

      The study’s co-authors include Joanie Van de Walle of WHOI, Samantha Patrick of the University of Liverpool, and Christophe Barbraud, Henri Weimerskirch, and Karine Delord of CNRS- La Rochelle University in France.

      Repeat divorcées

      The new study concentrates on a population of wandering albatross that return regularly to Possession Island in the Southern Indian Ocean to breed. This population has been the focus of a long-term study dating back to the 1950s, in which researchers have been monitoring the birds each breeding season and recording the pairings and breakups of individuals through the years.

      This particular population is skewed toward more male individuals than females because the foraging grounds of female albatrosses overlap with fishing vessels, where they are more prone to being accidentally caught in fishing lines as bycatch.  

      In earlier research, Sun analyzed data from this long-term study and picked up a curious pattern: Those individuals that divorced were more likely to do so again and again.

      “Then we wanted to know, what drives divorce, and why are some individuals divorcing more often,” Jenouvrier says. “In humans, you see this repetitive divorce pattern as well, linked to personality. And the wandering albatross is one of the rare species for which we have both demographic and personality data.”

      That personality data comes from an ongoing study that began in 2008 and is led by co-author Patrick, who has been measuring the personality of individuals among the same population of wandering albatross on Possession Island. In the study of animal behavior, personality is defined as a consistent behavioral difference displayed by an individual. Biologists mainly measure personality in animals as a gradient between shy and bold, or less to more aggressive.

      In Patrick’s study, researchers have measured boldness in albatrosses by gauging a bird’s reaction to a human approaching its nest, from a distance of about 5 meters. A bird is assigned a score depending on how it reacts (a bird that does not respond scores a zero, being the most shy, while a bird that lifts its head, and even stands up, can score higher, being the most bold).

      Patrick has made multiple personality assessments of the same individuals over multiple years. Sun and Jenouvrier wondered: Could an individual’s personality have anything to do with their chance to divorce?

      “We had seen this repetitive divorce pattern, and then talked with Sam (Patrick) to see, could this be related to personality?” Sun recalls. “We know that personality predicts divorce in human beings, and it would be intuitive to make the link between personality and divorce in wild populations.”

      Shy birds

      In their new study, the team used data from both the demographic and personality studies to see whether any patterns between the two emerged. They applied a statistical model to both datasets, to test whether the personality of individuals in an albatross pair affected the fate of that pair.

      They found that for females, personality had little to do with whether the birds divorced. But in males, the pattern was clear: Those that were identified as shy were more likely to divorce, while bolder males stayed with their partner.

      “Divorce does not happen very often,” Jenouvrier says. “But we found that the shyer a bird is, the more likely they are to divorce.”

      But why? In their study, the team puts forth an explanation, which ecologists call “forced divorce.” They point out that, in this particular population of wandering albatross, males far outnumber females and therefore are more likely to compete with each other for mates. Males that are already partnered up, therefore, may be faced with a third “intruder” — a male who is competing for a place in the pair.

      “When there is a third intruder that competes, shy birds could step away and give away their mates, where bolder individuals are aggressive and will guard their partner and secure their partnership,” Sun explains. “That’s why shyer individuals may have higher divorce rates.”

      The team is planning to extend their work to examine how the personality of individuals can affect how the larger population changes and evolves. 

      “Now we’re talking about a connection between personality and divorce at the individual level,” Sun says. “But we want to understand the impact at the population level.”

      This research was supported, in part, by the National Science Foundation. More

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      High-energy and hungry for the hardest problems

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      A high school track star and valedictorian, Anne White has always relished moving fast and clearing high hurdles. Since joining the Department of Nuclear Science and Engineering (NSE) in 2009 she has produced path-breaking fusion research, helped attract a more diverse cohort of students and scholars into the discipline, and, during a worldwide pandemic, assumed the role of department head as well as co-lead of an Institute-wide initiative to address climate change. For her exceptional leadership, innovation, and accomplishments in education and research, White was named the School of Engineering Distinguished Professor of Engineering in July 2020.

      But White declares little interest in recognition or promotions. “I don’t care about all that stuff,” she says. She’s in the race for much bigger stakes. “I want to find ways to save the world with nuclear,” she says.

      Tackling turbulence

      It was this goal that drew White to MIT. Her research, honed during graduate studies at the University of California at Los Angeles, involved developing a detailed understanding of conditions inside fusion devices, and resolving issues critical to realizing the vision of fusion energy — a carbon-free, nearly limitless source of power generated by 150-million-degree plasma.

      Harnessing this superheated, gaseous form of matter requires a special donut-shaped device called a tokamak, which contains the plasma within magnetic fields. When White entered fusion around the turn of the millennium, models of plasma behavior in tokamaks didn’t reliably match observed or experimental conditions. She was determined to change that picture, working with MIT’s state-of-the-art research tokamak, Alcator C-Mod.

      Play video

      Alcator C-Mod Tokamak Tour

      White believed solving the fusion puzzle meant getting a handle on plasma turbulence — the process by which charged atomic particles, breaking out of magnetic confinement, transport heat from the core to the cool edges of the tokamak. Although researchers knew that fusion energy depends on containing and controlling the heat of plasma reactions, White recalls that when she began grad school, “it was not widely accepted that turbulence was important, and that it was central to heat transport. She “felt it was critical to compare experimental measurements to first principles physics models, so we could demonstrate the significance of turbulence and give tokamak models better predictive ability.”

      In a series of groundbreaking studies, White’s team created the tools for measuring turbulence in different conditions, and developed computational models that could account for variations in turbulence, all validated by experiments. She was one of the first fusion scientists both to perform experiments and conduct simulations. “We lived in the domain between these two worlds,” she says.

      White’s turbulence models opened up approaches for managing turbulence and maximizing tokamak performance, paving the way for net-energy fusion energy devices, including ITER, the world’s largest fusion experiment, and SPARC, a compact, high-magnetic-field tokamak, a collaboration between MIT’s Plasma Science and Fusion Center and Commonwealth Fusion Systems.

      Laser-focused on turbulence

      Growing up in the desert city of Yuma, Arizona, White spent her free time outdoors, hiking and camping. “I was always in the space of protecting the environment,” she says. The daughter of two lawyers who taught her “to argue quickly and efficiently,” she excelled in math and physics in high school. Awarded a full ride at the University of Arizona, she was intent on a path in science, one where she could tackle problems like global warming, as it was known then. Physics seemed like the natural concentration for her.

      But there was unexpected pushback. The physics advisor believed her physics grades were lackluster. “I said, ‘Who cares what this guy thinks; I’ll take physics classes anyway,’” recalls White. Being tenacious and “thick skinned,” says White, turned out to be life-altering. “I took nuclear physics, which opened my eyes to fission, which then set me off on a path of understanding nuclear power and advanced nuclear systems,” she says. Math classes introduced her to chaotic systems, and she decided she wanted to study turbulence. Then, at a Society of Physics Students meeting White says she attended for the free food, she learned about fusion.

      “I realized this was what I wanted to do,” says White. “I became totally laser focused on turbulence and tokamaks.”

      At UCLA, she began to develop instruments and methods for measuring and modeling plasma turbulence, working on three different fusion research reactors, and earning fellowships from the Department of Energy (DOE) during her graduate and post-graduate years in fusion energy science. At MIT, she received a DOE Early Career Award that enabled her to build a research team that she now considers her “legacy.”

      As she expanded her research portfolio, White was also intent on incorporating fusion into the NSE curriculum at the undergraduate and graduate level, and more broadly, on making NSE a destination for students concerned about climate change. In recognition of her efforts, she received the 2014 Junior Bose Teaching Award. She also helped design the EdX course, Nuclear Engineering: Science, Systems and Society, introducing thousands of online learners to the potential of the field. “I have to be in the classroom,” she says. “I have to be with students, interacting, and sharing knowledge and lines of inquiry with them.”

      But even as she deepened her engagement with teaching and with her fusion research, which was helping spur development of new fusion energy technologies, White could not resist leaping into a consequential new undertaking: chairing the department. “It sounds cheesy, but I did it for my kid,” she says. “I can be helpful working on fusion, but I thought, what if I can help more by enabling other people across all areas of nuclear? This department gave me so much, I wanted to give back.”

      Although the pandemic struck just months after she stepped into the role in 2019, White propelled the department toward a new strategic plan. “It captures all the urgency and passion of the faculty, and is attractive to new students, with more undergraduates enrolling and more graduate students applying,” she says. White sees the department advancing the broader goals of the field, “articulating why nuclear is fundamentally important across many dimensions for carbon-free electricity and generation.” This means getting students involved in advanced fission technologies such as nuclear batteries and small modular reactors, as well as giving them an education in fusion that will help catalyze a nascent energy industry.

      Restless for a challenge

      White feels she’s still growing into the leadership role. “I’m really enthusiastic and sometimes too intense for people, so I have to dial it back during challenging conversations,” she says. She recently completed a Harvard Business School course on leadership.

      As the recently named co-chair of MIT’s Climate Nucleus (along with Professor Noelle Selin), charged with overseeing MIT’s campus initiatives around climate change, White says she draws on a repertoire of skills that come naturally to her: listening carefully, building consensus, and seeing value in the diversity of opinion. She is optimistic about mobilizing the Institute around goals to lower MIT’s carbon footprint, “using the entire campus as a research lab,” she says.

      In the midst of this push, White continues to advance projects of concern to her, such as making nuclear physics education more accessible. She developed an in-class module involving a simple particle detector for measuring background radiation. “Any high school or university student could build this experiment in 10 minutes and see alpha particle clusters and muons,” she says.

      White is also planning to host “Rising Stars,” an international conference intended to help underrepresented groups break barriers to entry in the field of nuclear science and engineering. “Grand intellectual challenges like saving the world appeal to all genders and backgrounds,” she says.

      These projects, her departmental and institutional duties, and most recently a new job chairing DOE’s Fusion Energy Sciences Advisory Committee leave her precious little time for a life outside work. But she makes time for walks and backpacking with her husband and toddler son, and reading the latest books by female faculty colleagues, such as “The New Breed,” by Media Lab robotics researcher Kate Darling, and “When People Want Punishment,” by Lily Tsai, Ford Professor of Political Science. “There are so many things I don’t know and want to understand,” says White.

      Yet even at leisure, White doesn’t slow down. “It’s restlessness: I love to learn, and anytime someone says a problem is hard, or impossible, I want to tackle it,” she says. There’s no time off, she believes, when the goal is “solving climate change and amplifying the work of other people trying to solve it.” More

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      Using seismology for groundwater management

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      As climate change increases the number of extreme weather events, such as megadroughts, groundwater management is key for sustaining water supply. But current groundwater monitoring tools are either costly or insufficient for deeper aquifers, limiting our ability to monitor and practice sustainable management in populated areas.

      Now, a new paper published in Nature Communications bridges seismology and hydrology with a pilot application that uses seismometers as a cost-effective way to monitor and map groundwater fluctuations.

      “Our measurements are independent from and complementary to traditional observations,” says Shujuan Mao PhD ’21, lead author on the paper. “It provides a new way to dictate groundwater management and evaluate the impact of human activity on shaping underground hydrologic systems.”

      Mao, currently a Thompson Postdoctoral Fellow in the Geophysics department at Stanford University, conducted most of the research during her PhD in MIT’s Department of Earth, Atmospheric and Planetary Sciences (EAPS). Other contributors to the paper include EAPS department chair and Schlumberger Professor of Earth and Planetary Sciences Robert van der Hilst, as well as Michel Campillo and Albanne Lecointre from the Institut des Sciences de la Terre in France.

      While there are a few different methods currently used for measuring groundwater, they all come with notable drawbacks. Hydraulic heads, which drill through the ground and into the aquifers, are expensive and can only give limited information at the specific location they’re placed. Noninvasive techniques based on satellite- or airborne-sensing lack the sensitivity and resolution needed to observe deeper depths.

      Mao proposes using seismometers, which are instruments used to measure ground vibrations such as the waves produced by earthquakes. They can measure seismic velocity, which is the propagation speed of seismic waves. Seismic velocity measurements are unique to the mechanical state of rocks, or the ways rocks respond to their physical environment, and can tell us a lot about them.

      The idea of using seismic velocity to characterize property changes in rocks has long been used in laboratory-scale analysis, but only recently have scientists been able to measure it continuously in realistic-scale geological settings. For aquifer monitoring, Mao and her team associate the seismic velocity with the hydraulic property, or the water content, in the rocks.

      Seismic velocity measurements make use of ambient seismic fields, or background noise, recorded by seismometers. “The Earth’s surface is always vibrating, whether due to ocean waves, winds, or human activities,” she explains. “Most of the time those vibrations are really small and are considered ‘noise’ by traditional seismologists. But in recent years scientists have shown that the continuous noise records in fact contain a wealth of information about the properties and structures of the Earth’s interior.”

      To extract useful information from the noise records, Mao and her team used a technique called seismic interferometry, which analyzes wave interference to calculate the seismic velocity of the medium the waves pass through. For their pilot application, Mao and her team applied this analysis to basins in the Metropolitan Los Angeles region, an area suffering from worsening drought and a growing population.

      By doing this, Mao and her team were able to see how the aquifers changed physically over time at a high resolution. Their seismic velocity measurements verified measurements taken by hydraulic heads over the last 20 years, and the images matched very well with satellite data. They could also see differences in how the storage areas changed between counties in the area that used different water pumping practices, which is important for developing water management protocol.

      Mao also calls using the seismometers a “buy-one get-one free” deal, since seismometers are already in use for earthquake and tectonic studies not just across California, but worldwide, and could help “avoid the expensive cost of drilling and maintaining dedicated groundwater monitoring wells,” she says.

      Mao emphasizes that this study is just the beginning of exploring possible applications of seismic noise interferometry in this way. It can be used to monitor other near-surface systems, such as geothermal or volcanic systems, and Mao is currently applying it to oil and gas fields. But in places like California currently experiencing megadroughts, and who rely on groundwater for a large portion of their water needs, this kind of information is key for sustainable water management.

      “It’s really important, especially now, to characterize these changes in groundwater storage so that we can promote data-informed policymaking to help them thrive under increasing water stress,” she says.

      This study was funded, in part, by the European Research Council, with additional support from the Thompson Fellowship at Stanford University. More

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      From bridges to DNA: civil engineering across disciplines

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      How is DNA like a bridge? This question is not a riddle or logic game, it is a concern of Johannes Kalliauer’s doctoral thesis.

      As a student at TU Wien in Austria, Kalliauer was faced with a monumental task: combining approaches from civil engineering and theoretical physics to better understand the forces that act on DNA.

      Kalliauer, now a postdoc at the MIT Concrete Sustainability Hub, says he modeled DNA as though it were a beam, using molecular dynamics principles to understand its structural properties.

      “The mechanics of very small objects, like DNA helices, and large ones, like bridges, are quite similar. Each may be understood in terms of Newtonian mechanics. Forces and moments act on each system, subjecting each to deformations like twisting, stretching, and warping,” says Kalliauer.

      As a 2020 article from TU Wien noted, Kalliauer observed a counterintuitive behavior when examining DNA at an atomic level. Unlike a typical spring which becomes less coiled as it is stretched, DNA was observed to become more wound as its length was increased. 

      In situations like these where conventional logic appears to break down, Kalliauer relies on the intuition he has gained as an engineer.

      “To understand this strange behavior in DNA, I turned to a fundamental approach: I examined what was the same about DNA and macroscopic structures and what was different. Civil engineers use methods and calculations which have been developed over centuries and which are very similar to the ones I employed for my thesis,” Kalliauer explains. 

      As Kalliauer continues, “Structural engineering is an incredibly versatile discipline. If you understand it, you can understand atomistic objects like DNA strands and very large ones like galaxies. As a researcher, I rely on it to help me bring new viewpoints to fields like biology. Other civil engineers can and should do the same.”

      Kalliauer, who grew up in a small town in Austria, has spent his life applying unconventional approaches like this across disciplines. “I grew up in a math family. While none of us were engineers, my parents instilled an appreciation for the discipline in me and my two older sisters.”

      After middle school, Kalliauer attended a technical school for civil engineering, where he discovered a fascination for mechanics. He also worked on a construction site to gain practical experience and see engineering applied in a real-world context.

      Kalliauer studied out of interest intensely, working upwards of 100 hours per week to better understand coursework in university. “I asked teachers and professors many questions, often challenging their ideas. Above everything else, I needed to understand things for myself. Doing well on exams was a secondary concern.”

      In university, he studied topics ranging from car crash testing to concrete hinges to biology. As a new member of the CSHub, he is studying how floods may be modeled with the statistical physics-based model provided by lattice density functional theory.

      In doing this, he builds on the work of past and present CSHub researchers like Elli Vartziotis and Katerina Boukin. 

      “It’s important to me that this research has a real impact in the world. I hope my approach to engineering can help researchers and stakeholders understand how floods propagate in urban contexts, so that we may make cities more resilient,” he says. More

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      in Environment

      Power, laws, and planning

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      Think about almost any locale where people live: Why does it have its current built form? Why do people reside where they do? No doubt there are quirks of geography or history involved. But places are also shaped by money, politics, and the law — in short, by power.

      Studying those issues is the work of Justin Steil, an associate professor in MIT’s Department of Urban Studies and Planning. Steil’s research largely focuses on cities, drawing out the ways that politics and the law sustain social divisions on the ground.

      Or, as Steil says, “The biggest theme that runs through my work is: How is power exercised through control of space, and access to particular places? What are the spatial and social and legal processes of inclusion and exclusion that generate or can address inequality, generally?”

      Those mechanisms can be found all around. Wealthy suburbs with large minimum lot sizes restrict growth and access to high-ranking school districts; gated communities take that process of separation even more literally; and many U.S. metro areas have island-like jurisdictions that have seceded from larger surrounding cities. City residential geography often displays the legacies of redlining (discrimination laws) and even century-old mob violence incidents used to curb integration.

      “I really like to try to get down to pinpoint what are the precise laws, ordinances, and policies, and specific social processes, which continue to generate inequality,” says Steil. “And ask: How can we change that to generate greater access to resources and opportunities?”

      While investigating questions that range widely across the theme of power and space, Steil has published many research articles and book chapters while helping edit volumes on the subject. For his research and teaching, Steil was awarded tenure at MIT earlier this year.

      Combining law and urban planning

      Steil grew up in New York City, where his surroundings helped him realize how much urban policy and laws matters. He attended Harvard University as an undergraduate, majored in African American Studies, and spent a summer as a student in South Africa in 1998, just as the country was launching its new democracy.

      “That had a big impact,” Steil says. “Both seeing the power of grassroots organizing and social movements, to overthrow this white supremacist government, but also to understand how the apartheid system had worked, the role of law and of space — how the landscape and built environment had been consciously designed to keep people separate and unequal.”

      Between graduating from college and finishing his PhD, Steil embarked on an odyssey of jobs in the nonprofit sector and graduate work on multiple academic disciplines, touching on pressing social topics. Steil worked at the City School in Boston, a youth leadership program; the Food Project, a Massachusetts agricultural program; two nonprofits in Juarez, Mexico, focused on preventing domestic violence and on environmental justice; and the New Economy Project in New York, studying predatory lending. In the midst of this, Steil took time to earn a master’s in city design and social science from the London School of Economics.

      “I learned so much from studying city design, and really enjoyed it,” Steil says of that program. “But I also realized that my personal strengths are not in design. … I was more interested and more capable in the social science realm.”

      With that in mind, Steil was accepted into a joint PhD and JD program at Columbia University, combining a law degree with doctoral studies in urban planning.

      “So much of urban planning is determined by law, by property law and constitutional law,” Steil says. “I felt that if I wanted to research and teach these things, I needed to understand the law.”

      After finishing his law school and doctoral courses, Steil’s dissertation, written under the guidance of the late Peter Marcuse, examined the policy responses of two sets of paired towns — two in Nebraska, two in Pennsylvania — to immigration. In each of the states, one town was far more receptive to immigrants than the other. Steil concluded that the immigration-receptive towns had more local organizations and civic connections that reached across economic classes; instead of being more atomized, they were more cohesive socially, and willing to create more economic opportunities for those willing to work for them.

      Without such ties, Steil notes, people can end up “seeing things as a zero-sum game, instead of seeing the possibilities for new residents to enliven and enrich and contribute to a community.”

      By contrast, he adds, “sustained collaboration across what people might have seen as differences toward a shared goal created opportunities for a dialogue about immigration, its challenges and benefits, to imagine a future that could include these new neighbors. There was an emphasis in some of those towns on being communities where people were proud of working hard, and respected other people who did that.”

      From PhD to EMT

      Steil joined the MIT faculty after completing his PhD in 2015, and has continued to produce work on an array of issues about policy, law, and inclusion. Some of that work bears directly on contemporary housing policy. With Nicholas Kelly PhD ’21, Lawrence Vale, the Ford Professor of Urban Design and Planning at MIT, and Maia Woluchem MCP ’19, he co-edited the volume “Furthering Fair Housing” (Temple University Press, 2021), which analyzes recent political clashes over federal fair-housing policy.

      Some of Steil’s other work is more historically oriented. He has published multiple papers on race and housing in the early 20th century, when both violence against Blacks and race-based laws kept many cities segregated. As Steil notes, U.S. laws have been rewritten so as to be no longer explicitly race-based. However, he notes, “That legacy, entrenched into the built environment, is very durable.”

      There are also significant effects stemming from the local, property-tax-based system of funding education in the U.S., another policy approach that effectively leaves many Americans living in very different realms of metro areas.

      “By fragmenting [funding] at the local level and then having resources redistributed within these small jurisdictions, it creates powerful incentives for wealthy households and individuals to use land-use law and other law to exclude people,” Steil says. “That’s partly why we have this tremendous crisis of housing affordability today, as well as deep inequalities in educational opportunities.”

      Since arriving at MIT, Steil has also taught on these topics extensively. The undergraduate classes he teaches include an introduction to housing and community development, a course on land use and civil rights law, another course on land use and environmental law, and one on environmental justice.

      “What an amazing privilege it is to be here at MIT, and learn every day, from our students, our undergraduate and graduate students, and from my colleagues,” Steil says. “It makes it fun to be here.”

      As if Steil didn’t have enough on his plate, he takes part in still another MIT-based activity: For the last few years, he has worked as an Emergency Medical Technician (EMT) for MIT’s volunteer corps, having received his training from MIT’s EMT students since arriving on campus.

      As Steil describes it, his volunteer work has been a process of “starting out at the bottom of the totem pole as a beginning EMT and being trained by other students and progressing with my classmates.”

      It is “amazing,” he adds, to work with students and see “their dedication to this service and to MIT and to Cambridge and Boston, how hard they work and how capable they are, and what a strong community gets formed through that.” More

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      in Environment

      Passion projects prepare to launch

      by

      At the start of the sixth annual MITdesignX “Pitch Day,” Svafa Grönfeldt, the program’s faculty director, made a point of noting that many of the teams about to showcase their ventures had changed direction multiple times on their projects.

      “Some of you have pivoted more times than we can count,” Grönfeldt said in her welcoming address. “This makes for a fantastic idea because you have the courage to actually question if your ideas are the right ones. In the true spirit of human-centered design, you actually try to understand the problem before you solve it!”

      MITdesignX, a venture accelerator based in the School of Architecture and Planning, is an interdisciplinary academic program operating at the intersection of design, business, and technology. The launching pad for startups focuses on applying design to engage complex problems and discovering high-impact solutions to address critical challenges facing the future of design, cities, and the global environment. The program reflects a new approach to entrepreneurship education, drawing on business theory, design thinking, and entrepreneurial practices.

      At this year’s event, 11 teams pitched their ideas before a panel of three judges, an on-site audience, and several hundred viewers watching the livestream event.

      “These teams have been working hard on solutions,” Gilad Rosenzweig, executive director of MITdesignX, told the audience. “They’re not designing solutions for people. They’re designing solutions with people.”

      Solving urgent problems

      Some of the issues addressed by the teams were lack of adequate housing, endangered food supplies, toxic pollution, and threats to democracy. Many of the students were inspired to create their venture because of problems they encountered in their careers or concerns impacting their home countries. The 25 team members in this year’s cohort represent work on five continents.

      “We’re very proud of our international representation because we want our impact to be felt outside of Cambridge,” said Rosenzweig. “We want to make an impact around the country and around the world.”

      John Devine, a JD/Masters in City Planning (MCP) candidate in the Department of Urban Studies and Planning, created a new software platform, “Civic Atlas.” In his pitch, he explained that having worked in city planning in Texas for a decade before coming to MIT, he saw how difficult it was for communities to wade through and comprehend the dense, technical language in city council agendas. Zoning cases, bond projects, and transportation investments are just some of the significant projects that affect a community, and Devine saw many instances where decisions were being made without community awareness as a result of inadequate communication.

      “When communities don’t have access to clear, accessible information, we have poor outcomes,” Devine told the audience. “I realized the solution to this is to make accessible and inclusive digital experiences that really facilitate communication between planners, developers, and members of the community.”

      Seizing the opportunity, Devine taught himself how to code and built a fully automated web tool for the Dallas City Planning Commission. The tool checks the city’s website daily and translates documents into interactive maps, allowing residents to view plans in their community. Devine is starting in Dallas, but says that there are more than 800 cities across the United States with a population greater than 50,000 that present an excellent target market for this product.

      “I think cities have a ton to gain from working with us, including building trust and communication with constituents — something that’s vital for city halls to function,” says Devine.

      Next steps for the cohort

      The judges for this year’s event — Yscaira Jimenez, founder of LaborX; Magnus Ingi Oskarsson of Eyrir Venture Management in Reykjavik, Iceland; and Frank Pawlitschek, director, HPI School of Entrepreneurship in Potsdam, Germany — deliberated to identify the best teams based on three criteria: most innovative, greatest impact, and best presentation. The competition was so strong that the judges decided to award two honorable mentions. This year’s awardees are:

      Atacama, a company that is developing biomaterials to replace plastics, received the “Most Innovative” award and $5,000. The company accelerates the adoption of renewable and sustainable materials through machine learning and robotics, ensuring performance, cost-effectiveness, and environmental impact. Its founders are Paloma Gonzalez-Rojas PhD ’21, Jose Tomas Dominguez, and Jose Antonio Gonzalez.
      Grain Box, a startup focusing on optimizing the post-harvest supply chain for smallholder farmers in rural India, was awarded “Greatest Impact” and a $5,000 award. Its founders are Mona Vijaykumar SMArchS ’22 and T.R. (Radha) Radhakrishnan.
      Lamarr.AI, which offers an autonomous solution for rapid building envelope diagnostics using AI and cloud computing, was recognized for “Best Presentation” and awarded $2,500. Its founders are Norhan Bayomi PhD ’22, Tarek Rakha, PhD ’15, and John E. Fernandez ’85, professor and director of the MIT Environmental Solutions Initiative.
      Honorable Mention: “News Detective,” a platform combining moderated, professional fact-checking and AI to fight misinformation on social media, created by rising senior Ilana Strauss.
      Honorable Mention: “La Firme,” which digitizes architectural services to reach families who self-build their homes in Latin America, created by Mora Orensanz MCP ’21, Fiorella Belli Ferro MCP ’21, and rising senior Raul Briceno Brignole.
      Following the award ceremony, Rosenzweig told the students that the process was not yet over because MITdesignX faculty and staff would always be available to continue guiding and supporting their journeys as they launch and grow their ventures.

      “You’re going to become alumni of MITdesignX,” he said. “You’re going to be joining over 50 teams that are working around the world, making an impact. They’re being recognized as leaders in innovation. They’re being recognized by investors who are helping them make an impact. This is your next step.” More