Wednesday, June 17th, 2020

Time	Event
9:55a	Why the Mediterranean is a climate change hotspot Although global climate models vary in many ways, they agree on this: The Mediterranean region will be significantly drier in coming decades, potentially seeing 40 percent less precipitation during the winter rainy season. An analysis by researchers at MIT has now found the underlying mechanisms that explain the anomalous effects in this region, especially in the Middle East and in northwest Africa. The analysis could help refine the models and add certainty to their projections, which have significant implications for the management of water resources and agriculture in the region. The study, published last week in the Journal of Climate, was carried out by MIT graduate student Alexandre Tuel and professor of civil and environmental engineering Elfatih Eltahir. The different global circulation models of the Earth’s changing climate agree that temperatures virtually everywhere will increase, and in most places so will rainfall, in part because warmer air can carry more water vapor. However, “There is one major exception, and that is the Mediterranean area,” Eltahir says, which shows the greatest decline of projected rainfall of any landmass on Earth. “With all their differences, the models all seem to agree that this is going to happen,” he says, although they differ on the amount of the decline, ranging from 10 percent to 60 percent. But nobody had previously been able to explain why. Tuel and Eltahir found that this projected drying of the Mediterranean region is a result of the confluence of two different effects of a warming climate: a change in the dynamics of upper atmosphere circulation and a reduction in the temperature difference between land and sea. Neither factor by itself would be sufficient to account for the anomalous reduction in rainfall, but in combination the two phenomena can fully account for the unique drying trend seen in the models. The first effect is a large-scale phenomenon, related to powerful high-altitude winds called the midlatitude jet stream, which drive a strong, steady west-to-east weather pattern across Europe, Asia, and North America. Tuel says the models show that “one of the robust things that happens with climate change is that as you increase the global temperature, you're going to increase the strength of these midlatitude jets.” But in the Northern Hemisphere, those winds run into obstacles, with mountain ranges including the Rockies, Alps, and Himalayas, and these collectively impart a kind of wave pattern onto this steady circulation, resulting in alternating zones of higher and lower air pressure. High pressure is associated with clear, dry air, and low pressure with wetter air and storm systems. But as the air gets warmer, this wave pattern gets altered. “It just happened that the geography of where the Mediterranean is, and where the mountains are, impacts the pattern of air flow high in the atmosphere in a way that creates a high pressure area over the Mediterranean,” Tuel explains. That high-pressure area creates a dry zone with little precipitation. However, that effect alone can’t account for the projected Mediterranean drying. That requires the addition of a second mechanism, the reduction of the temperature difference between land and sea. That difference, which helps to drive winds, will also be greatly reduced by climate change, because the land is warming up much faster than the seas. “What’s really different about the Mediterranean compared to other regions is the geography,” Tuel says. “Basically, you have a big sea enclosed by continents, which doesn’t really occur anywhere else in the world.” While models show the surrounding landmasses warming by 3 to 4 degrees Celsius over the coming century, the sea itself will only warm by about 2 degrees or so. “Basically, the difference between the water and the land becomes a smaller with time,” he says. That, in turn, amplifies the pressure differential, adding to the high-pressure area that drives a clockwise circulation pattern of winds surrounding the Mediterranean basin. And because of the specifics of local topography, projections show the two areas hardest hit by the drying trend will be the northwest Africa, including Morocco, and the eastern Mediterranean region, including Turkey and the Levant. That trend is not just a projection, but has already become apparent in recent climate trends across the Middle East and western North Africa, the researchers say. “These are areas where we already detect declines in precipitation,” Eltahir says. It’s possible that these rainfall declines in an already parched region may even have contributed to the political unrest in the region, he says. “We document from the observed record of precipitation that this eastern part has already experienced a significant decline of precipitation,” Eltahir says. The fact that the underlying physical processes are now understood will help to ensure that these projections should be taken seriously by planners in the region, he says. It will provide much greater confidence, he says, by enabling them “to understand the exact mechanisms by which that change is going to happen.” Eltahir has been working with government agencies in Morocco to help them translate this information into concrete planning. “We are trying to take these projections and see what would be the impacts on availability of water,” he says. “That potentially will have a lot of impact on how Morocco plans its water resources, and also how they could develop technologies that could help them alleviate those impacts through better management of water at the field scale, or maybe through precision agriculture using higher technology.” The work was supported by the collaborative research program between Université Mohamed VI Polytechnique in Morocco and MIT. (Comment on this)
11:00a	Astronomers detect regular rhythm of radio waves, with origins unknown A team of astronomers, including researchers at MIT, has picked up on a curious, repeating rhythm of fast radio bursts emanating from an unknown source outside our galaxy, 500 million light years away. Fast radio bursts, or FRBs, are short, intense flashes of radio waves that are thought to be the product of small, distant, extremely dense objects, though exactly what those objects might be is a longstanding mystery in astrophysics. FRBs typically last a few milliseconds, during which time they can outshine entire galaxies. Since the first FRB was observed in 2007, astronomers have catalogued over 100 fast radio bursts from distant sources scattered across the universe, outside our own galaxy. For the most part, these detections were one-offs, flashing briefly before disappearing entirely. In a handful of instances, astronomers observed fast radio bursts multiple times from the same source, though with no discernible pattern. This new FRB source, which the team has catalogued as FRB 180916.J0158+65, is the first to produce a periodic, or cyclical pattern of fast radio bursts. The pattern begins with a noisy, four-day window, during which the source emits random bursts of radio waves, followed by a 12-day period of radio silence. The astronomers observed that this 16-day pattern of fast radio bursts reoccurred consistently over 500 days of observations. “This FRB we’re reporting now is like clockwork,” says Kiyoshi Masui, assistant professor of physics in MIT’s Kavli Institute for Astrophysics and Space Research. “It’s the most definitive pattern we’ve seen from one of these sources. And it’s a big clue that we can use to start hunting down the physics of what’s causing these bright flashes, which nobody really understands.” Masui is a member of the CHIME/FRB collaboration, a group of more than 50 scientists led by the University of British Columbia, McGill University, University of Toronto, and the National Research Council of Canada, that operates and analyzes the data from the Canadian Hydrogen Intensity Mapping Experiment, or CHIME, a radio telescope in British Columbia that was the first to pick up signals of the new periodic FRB source. The CHIME/FRB Collaboration has published the details of the new observation today in the journal Nature. A radio view In 2017, CHIME was erected at the Dominion Radio Astrophysical Observatory in British Columbia, where it quickly began detecting fast radio bursts from galaxies across the universe, billions of light years from Earth. CHIME consists of four large antennas, each about the size and shape of a snowboarding half-pipe, and is designed with no moving parts. Rather than swiveling to focus on different parts of the sky, CHIME stares fixedly at the entire sky, using digital signal processing to pinpoint the region of space where incoming radio waves are originating. From September 2018 to February 2020, CHIME picked out 38 fast radio bursts from a single source, FRB 180916.J0158+65, which the astronomers traced to a star-churning region on the outskirts of a massive spiral galaxy, 500 million light years from Earth. The source is the most active FRB source that CHIME has yet detected, and until recently it was the closest FRB source to Earth. As the researchers plotted each of the 38 bursts over time, a pattern began to emerge: One or two bursts would occur over four days, followed by a 12-day period without any bursts, after which the pattern would repeat. This 16-day cycle occurred again and again over the 500 days that they observed the source. “These periodic bursts are something that we’ve never seen before, and it’s a new phenomenon in astrophysics,” Masui says. Circling scenarios Exactly what phenomenon is behind this new extragalactic rhythm is a big unknown, although the team explores some ideas in their new paper. One possibility is that the periodic bursts may be coming from a single compact object, such as a neutron star, that is both spinning and wobbling — an astrophysical phenomenon known as precession. Assuming that the radio waves are emanating from a fixed location on the object, if the object is spinning along an axis and that axis is only pointed toward the direction of Earth every four out of 16 days, then we would observe the radio waves as periodic bursts. Another possibility involves a binary system, such as a neutron star orbiting another neutron star or black hole. If the first neutron star emits radio waves, and is on an eccentric orbit that briefly brings it close to the second object, the tides between the two objects could be strong enough to cause the first neutron star to deform and burst briefly before it swings away. This pattern would repeat when the neutron star swings back along its orbit. The researchers considered a third scenario, involving a radio-emitting source that circles a central star. If the star emits a wind, or cloud of gas, then every time the source passes through the cloud, the gas from the cloud could periodically magnify the source’s radio emissions. “Maybe the source is always giving off these bursts, but we only see them when it’s going through these clouds, because the clouds act as a lens,” Masui says. Perhaps the most exciting possibility is the idea that this new FRB, and even those that are not periodic or even repeating, may originate from magnetars — a type of neutron star that is thought to have an extremely powerful magnetic field. The particulars of magnetars are still a bit of a mystery, but astronomers have observed that they do occasionally release massive amounts of radiation across the electromagnetic spectrum, including energy in the radio band. “People have been working on how to make these magnetars emit fast radio bursts, and this periodicity we’ve observed has since been worked into these models to figure out how this all fits together,” Masui says. Very recently, the same group made a new observation that supports the idea that magnetars may in fact be a viable source for fast radio bursts. In late April, CHIME picked up a signal that looked like a fast radio burst, coming from a flaring magnetar, some 30,000 light years from Earth. If the signal is confirmed, this would be the first FRB detected within our own galaxy, as well as the most compelling evidence of magnetars as a source of these mysterious cosmic sparks. (Comment on this)
2:15p	Building a framework for remote making Making is central to MIT’s identity. It is the embodiment of MIT’s motto, "mens et manus" — "mind and hand." For many students, making is more than designing, engineering, arts, and crafts; it is an act of community. But as campus closed in response to the Covid-19 pandemic in March, makerspaces were shuttered across campus and many students had to abandon their projects. With most of these spaces remaining closed to students over the summer, a remote making resource site for students was recently launched to enable safe making from home. Developed by MIT Project Manus and MIT Environment, Health, and Safety (EHS), the site functions as a wiki guiding students and their faculty supervisors’ decisions about how to make remotely while still putting safety first. “We created this framework for decision-making about what is and what is not okay to do off campus in terms of making things for MIT-sponsored purposes,” says Martin Culpepper, professor of mechanical engineering and director of Project Manus. The idea for the framework stemmed from a number of conversations Culpepper and Tolga Durak, managing director of EHS Programs at MIT, had with faculty and students shortly after campus closed in March. Many were unsure what, if any, kinds of making activities were safe for students to do remotely. Out of an abundance of caution, some faculty didn’t feel comfortable asking students to do even simple, elementary-level making remotely. “We want to say 'yes' as much as possible to students asking to make things at home. But making doesn’t matter at MIT if it isn’t done safely,” Culpepper adds. Culpepper teamed up with Durak to create a set of guidelines that provided a clear path to students and faculty interested in making remotely this summer. Together, their teams developed a wiki that details how to approach remote making by different activity types such as chemistry, woodworking, and 3D printing. “We are trying to find ways to enable activities that are in MIT’s core DNA to take place even during these difficult times," says Durak. Color coding by risk The wiki is informed by a color-coded key that clearly indicates what steps to take depending on the tools and materials a student will be using for their MIT-sponsored projects. Green tools include a set of low-risk tools that don’t require tool specific training. Things like scissors, latex house paint, and sewing machines fall under the green category. Students aren’t required to ask for permission to use these items for MIT-sponsored making. “Green light items are low-risk enough that even grade school aged kids can use them,” explains Culpepper. “The framework gives students and faculty members peace of mind that they don’t have to ask and can proceed with using these tools.” The next tier of tools, yellow, are also considered low-risk but may require additional training, preparation, or PPE. These include many items found a local hardware stores such as hand drills or Dremel tools. Students who need to use these items to complete their work for MIT must sign a risk acknowledgement form and fill out a safety checklist. The Project Manus and EHS teams will then review the checklist and give written permission for students to use them. Tools that pose moderate risk are classified as orange. Items such as table saws, wood lathes, propane torches, and many chemicals are included under this category. “Orange tools fall in the middle. Many students have probably used them at home before, but when using them for MIT purposes we really want to make sure they understand all the hazards and make a plan to use them safely,” Culpepper says. As with yellow tools, students are required to sign a risk acknowledgement form to use orange tools. They are also required to develop a safety plan which they will then discuss with a member of the Project Manus and EHS teams. Tools in the red category are considered high risk tools and technologies that would typically only be used under supervision on campus. Nuclear materi­­­als, composites and resins, and industrial adhesives are some of the items that fall under this category. Permission to work with any of these tools or materials at the request of MIT faculty would be exceedingly rare and only permitted under extraordinary circumstances. Culpepper acknowledges that some students will have access to tools at home, while others may not. Ensuring equity in tool access is an important component of remote making. In cases where a tool or material is required for an MIT sponsored project, the research lead or faculty member would be responsible for providing their students with tools. If a tool or material can’t be shipped to a student’s address, the Project Manus and EHS team will work with them on identifying open makerspaces nearby that might be able to help. The framework will be piloted over the summer. In particular, the Project Manus and EHS teams hope faculty and students participating in the summer Undergraduate Research Opportunities Program (UROP) will be able to utilize it. “This framework will help us rejuvenate the UROP program in a different mode than we are used to,” adds Durak. “We aren’t going to stay stagnant just because everyone is remote. We want to focus on doing things safely instead of being in a state of paralysis.” Connecting the making community Each maker space and making program at MIT has its own culture and community. Since shifting to remote education this spring, these communities have had to be agile and develop new ways to foster that sense of community. Angelina Jay, technical instructor at Project Manus and director of the MakerLodge Program, turned to Zoom to keep the making community connected. “We’ve been hosting a crafting corner each week for students, faculty, and staff to hang out on Zoom,” Jay explains. “It’s a great way to carve out some time each week for making – whether it’s coloring for an hour, making origami, or building a robot.” While this crafting corner and other similar remote meet-ups like it focus on personal projects that aren’t part of an official MIT research or learning, Jay expects the framework could help guide students’ personal making projects as well. Whether it’s for informal crafting corners or UROP research projects, the framework can help re-establish the sense of community that was lost for many in the transition to remote work. “There is a significant concern that people are feeling isolated right now,” says Durak. “The hope is that this framework will help us feel like a community again while also keeping people safe.” Looking to the future Culpepper and Durak expect to iterate and improve the framework and related resources throughout the pilot phase this summer. Regardless of which scenario is chosen for fall semester, the framework will likely be a tool faculty can utilize in their courses. “Even in the best-case scenario for fall, there will still be value in facilitating remote making for students who, for whatever reason, are unable to be on campus,” adds Durak. “In the worst-case scenario, then the framework makes us far better prepared.” The Project Manus and EHS teams will be running a class this summer to train faculty, EHS and safety professionals, and technical staff on how to facilitate remote making safely. Using the information learned over the summer, the team will also share their experiences with peers at other institutions. “MIT is in a position to lead the charge. Even when things go back to normal, we can use what we learn through this framework and find a “second gear” for what is possible with both on site and remote making at MIT,” says Durak. (Comment on this)
3:50p	Ice, ice, maybe From above, Antarctica appears as a massive sheet of white. But if you were to zoom in, you would find that an ice sheet is a complex and dynamic system. In the Department of Earth, Atmospheric and Planetary Sciences (EAPS), graduate student Meghana Ranganathan studies what controls the speed of ice streams — narrow, fast-flowing sections of the glacier that funnel into the ocean. When they meet the ocean, losing ground support, they calve and break off into icebergs. This is the fastest route of ice mass loss in a changing climate. Looking at the microstructure, there are many components that can affect the speed with which the ice flows, Ranganathan explains, including its interaction with the land the ice sits on, the crystalline structure of the ice, and the orientation and size of the grains of ice. And, unfortunately, many models do not take these minute factors into consideration, which can impact their predictions. That is what she hopes to improve, modifying the mathematics and building models that eliminate assumptions by fleshing out the details of exactly what is happening down to a microscopic level. Ranganathan is equipped to handle such a topic, holding a bachelor’s degree in mathematics from Swarthmore College, where she generated food chain models to investigate extinction levels. She left her undergraduate studies with a “desire to save the world” and knew she wanted to apply her knowledge to climate science for her graduate degree. “We’re one of the first generations that grew up hearing about the climate crisis, and I think that made quite an impact on me,” she says. It’s also a “sweet spot,” she claims, in terms of being both a scientifically invigorating problem — with a lot of mathematical complexities — and a societal issue: “My desire to use math to discover things about the world, and my desire to help the world intersect in climate science.” A climate of opportunity EAPS allowed Ranganathan the flexibility to choose her field of focus within the wide range of climate science. “EAPS is a great department in diversity of fields,” she says. “It’s rare for one department to encompass so many aspects of earth and planetary sciences.” She lists faculty addressing everything from hurricanes to climate variability to biological oceanography and even exoplanetary studies. “Even now that I’ve found a research focus, I get to learn about other fields and stay in touch with current research being done across the earth sciences,” she adds. Flexibility is something she also attributes to her fellowship. Currently, Ranganathan is sponsored by the Sven Treitel Fellowship, and it’s this support that has allowed her the opportunity to develop and grow her independence, transitioning from student to researcher. “Graduate school is arguably not necessarily to learn a field, but rather to learn how to build on your own ideas,” she explains. Without having her time consumed by writing grant proposals or working on other people’s funded projects, she can divert her full attention to the topic she chooses. “This fellowship has really enabled me to focus on what I’m here to do: learn to be a scientist.” The Sven Treitel Graduate Student Support Fund was established in 2016 by EAPS alumnus Arthur Cheng ScD ’78 to honor Sven Treitel ’53, SM ’55, PhD ’58. “Sven Treitel was a visiting professor at MIT when I was a graduate student, and he was a great role model for me,” says Cheng. Treitel’s contributions to making seismograms more accurate are considered instrumental to bringing about the “digital revolution” of seismology. Years of change Currently in her third year, Ranganathan has passed her qualifying exam and is now fully devoted to her project. That includes facing some challenges in her research, like producing new models or, at least, new additions to preexisting models to make them suitable for ice streams. She also worries about what she calls a dearth of data needed to provide her model some benchmarks. Her excitement isn’t deterred, though, and she’s invigorated by the prospect of self-directing how she tackles these technical obstacles with input from her advisor, Cecil and Ida Green Career Development Professor Brent Minchew. During the Covid-19 crisis, Ranganathan appreciates the EAPS department and her advisor for ensuring that events and check-ins remain a regular occurrence in addition to prioritizing mental health. Although she has adjusted her hours and workflow, Ranganathan believes she has been relatively lucky while MIT campus has limited access. “My work is quite easy to take remote, since it is entirely computer-based work. So, my days haven't changed too much, with the exception of my physical location,” she notes. “The biggest trick I've learned is to be OK with everything not being exactly the same as it would have been if we were working in person.” Ranganathan still meets with her office mate every morning for coffee, albeit virtually, and continues to find encouragement in her fellow lab group-mates, whom she describes as smart, driven, and diverse, and brought together by a love for ice and glaciers. She considers the EAPS students in general a warming part of being at MIT. “They’re passionate and friendly. I love how active our students are in science communication, outreach, and climate activism,” she comments. Ice sheets of paper The co-president of the WiXII (Women in Course 12 group), Ranganathan is well-versed in communication and outreach herself. She enjoys writing — fiction as well as journalism — and has previously contributed articles to Scientific American. She uses her writing as a means to elevate awareness of climate issues and generally focuses on the interplay between climate and society. Her 2019 TEDx talk focused on human relationships with ice — how the last two decades of scientific study has completely changed how society understands ice sheets. Amazingly, all of Ranganathan’s knowledge of earth science, climate science, and glaciology, she has learned since joining MIT in 2017. “I never realized how much you learn so quickly in graduate school.” She hopes to continue down a similar track in her future career, addressing important aspects of glaciology that still need answers. She might want to try field work someday. When asked what’s left to accomplish, she joked, “Do the thesis! Write the thesis!”  (Comment on this)

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