For UMBC alum Nathan Kurtz, the only thing scarier than a surprise visit from a polar bear is a melting ice cap.
When the Polarstern set sail from northern Norway in September 2019, it was looking to get stuck in the ice. But this goal—a death knell for so many historic exploration ships—would be much harder for this modern research vessel to accomplish due to a shrinking ice pack.
The Polarstern was embarking on history’s largest scientific expedition to the Arctic to date. But before the first wave of scientists could start their research, they had to find a suitably robust ice pack, known as a floe, to make their home. This is harder than it sounds in the rapidly warming Arctic. An increasing amount of ice doesn’t survive the summer, which means boats have to travel further north in search of suitably thick ice. But after a nearly two-week journey from Norway, the Polarstern had found its mark.
And this is how Nathan Kurtz, M.S. ’07, Ph.D. ’09, atmospheric physics, ended up standing guard on some floating ice 300 miles from the North Pole armed with a rifle and a mandate to keep an eye out for polar bears.
Kurtz was part of the first wave of more than 600 scientists from 20 different countries who over the course of the year cycled through the ship as it drifted more than 1500 miles locked in a massive sheet of ice. The goal of the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition was to better understand the link between the Arctic environment and climate change.
Polar bear lookout was “not something I saw myself doing when I was in grad school,” says Kurtz, who didn’t see any bears that day, but by the time he returned to civilization a month later he’d had his fill. “However, UMBC really did prepare me to face challenges,” says Kurtz. “For me, grad school was hard, but it helped me with self-confidence—that this can be done and I can do this.”
Neither Kurtz nor his shipmates had traveled all the way to the Arctic to be polar bear sentinels. It was just a necessary part of the journey that allowed them to do their real job: collecting massive amounts of data on the woefully understudied polar environment. Over the course of its Arctic sojourn, the Polarstern hosted scientists studying everything from zooplankton beneath the ice to the clouds floating above it.
But for Kurtz, the ice itself was the main attraction.
From Icy Moons to Polar Ice Caps
Kurtz’s arrival in the Arctic was the culmination of over a decade of research studying Arctic floes from afar. But his original focus was ice even farther away—the icy moons of Jupiter. A shift in funding from NASA had Kurtz pivot his focus from astrophysics to earth sciences. “But physics applies to the moons of Jupiter and to the Earth,” Kurtz puts it dryly, “so it wasn’t so difficult to switch my focus.”
One of Kurtz’s advisors at UMBC, Raymond Hoff, professor emeritus, says UMBC students are uniquely positioned to lead in atmospheric physics, considered a unique subset in a field that often prioritizes astronomy or astrophysics. UMBC’s relationship with the Earth Science Division of NASA Goddard Space Flight Center to form the Joint Center for Earth Systems Technology allows students to play an active role in ongoing research.
Hoff himself brought valuable Arctic experience to his classroom, and Kurtz remembers being struck by his advisor’s journeys to the Arctic in the early 1980s. “What amazed me about the Arctic was the stark and pristine beauty of the landscape,” says Hoff. “Even at -45ºF, you would find yourself outside marvelling at the ice crystals which fell out of clear blue skies as any water vapor there would freeze and fall out on your parka.” For about 20 years, Hoff measured pollution at Alert, Northwest Territories, Canada, about as far north as he could get on land. There, researchers discovered that sulfur pollution from Europe and Russia was getting into the high Arctic.
“As a result of our work,” shares Hoff, “the Arctic nations brought in scientific agreements to reduce the inputs of mid-latitudinal pollution going to the Arctic. Some of those pollutants were really surprising since they were pesticides which were used in the tropics. It brought home how small our planet is.”
Kurtz’s work four decades later would continue to rely on the cooperation of numerous stakeholders, as scientists collaborated to study—and perhaps stymie—global warming.
Bridging the Ice Knowledge Gap
As a graduate student, Kurtz worked on methods for determining sea ice thickness based on data from NASA’s ICESat, a polar observation satellite launched in 2003. After earning his Ph.D., Kurtz has continued his work on the properties of polar ice as a scientist at NASA Goddard’s Cryospheric Sciences Branch.
To understand how ice around the poles is changing and what this can tell us about the climate, Kurtz and his colleagues relied heavily on laser data from ICESat, a satellite that passed over the poles bouncing laser light off the ice 40 times per second to get a high resolution map of the sea ice thickness. But when ICESat’s last laser failed in 2009, NASA was left without a dedicated satellite to study the ice caps.
NASA’s solution was slightly more hands-on than a satellite—following the laser failure, NASA launched Operation IceBridge. Like ICESat, IceBridge used laser altimeters and radar to observe the Arctic ice sheet, except now they’d use a manned turboprop plane to accomplish the same thing.
Kurtz took over Operation IceBridge in 2015 and helmed the mission until 2018. Hoff shares a story of tuning in to NASA TV to see a story labeled incorrectly on the TV Guide channel as “Ice Bride.” It was really about IceBridge. “You have to laugh,” says Hoff. “I was happy to watch that story and see Nate standing on the ice in the Arctic talking about how important ice thickness is to our understanding of the progression of global warming.”
Each season, Kurtz would travel to the poles for weeks at a time to survey the ice from the air. In the Arctic, Kurtz and his team would depart from an airbase in Greenland and spend upward of eight hours per day in the fuselage of a plane as it zig-zagged back and forth across the Arctic Circle. They would pass the time monitoring the instruments, watching movies, or simply taking in the alien landscape below.
“The scenery outside was really amazing,” Kurtz says. “I never got tired of looking out the window.”
Even if Kurtz wanted to spend more time in the IceBridge plane, the extreme polar weather limited operations to about three months out of the year, which made it difficult to comprehensively survey the polar regions. The upshot was the plane could carry far more instruments than ICESat, including ice penetrating radars that could only work at low altitudes. In this sense IceBridge drastically improved NASA’s understanding of the dynamics of polar ice—but Kurtz wanted to get closer still.
Since 2018, Kurtz has been studying polar ice data sent back by NASA’s shiny new orbiter, ICESat-2, at Goddard Space Flight Center in Maryland. But when he heard about the MOSAiC mission, Kurtz saw a once-in-a-lifetime opportunity. “I had done the airborne work, but on the ground field work is so different,” he says. “Being there would give me a totally different view of how the ice forms and help inspire me to use airborne and satellite data in a different way.”
A New Era of Polar Exploration
One does not simply book a ticket on a month-long trip to the Arctic, of course. After securing the funding to participate in MOSAiC’s research program, Kurtz was required to participate in extensive training in New Hampshire and northern Alaska before departure. Over the course of several weeks in summer 2019, Kurtz along with fellow scientists learned how to shoot a rifle and a flare gun, escape from a sinking helicopter, orchestrate a sea rescue, and protect themselves from polar bears. They were also trained in the art of doing science in the Arctic, learning how to use a giant drill to extract an ice core and drive a snowmobile.
The extensive training was necessary to prepare the scientists for the brutal environment. During the Arctic winter, temperatures can dip dozens of degrees below zero and starting in mid-October the Polarstern would witness five months of total darkness.
Kurtz recalls reading novels like Endurance, which chronicles explorer Ernest Shackleton’s harrowing efforts to reach the South Pole in 1914. “This book kept sticking in my head even though I felt safe on the ship. There were all kinds of modern communication in case we needed help or ran out of something or if there was some kind of emergency—we could at least talk to someone,” says Kurtz. “Shackleton and his group had none of that. I can’t even imagine.”
In this modern journey, participants would face some of the same challenges as past expeditions—unstable ice sheets, the threat of frostbite, the prospect of hungry bears, diminishing stores of fresh produce—along with new ones: they were limited to just 50 kilobytes of email data per day—barely enough to send a photo. But aside from a brief bout of seasickness during the passage from Norway, Kurtz quickly adapted to the life of a polar seafarer.
A Fresh Perspective on the Ice
To be sure, the days were both literally and figuratively long. When Kurtz and his crewmates arrived in the Arctic at the tail end of summer, the sun was hanging just below the horizon, casting the already alien landscape in a perpetual twilight glow. But given how much work there was to do, the extended daylight was a blessing. As the first of six expedition teams that cycled through the Polarstern that year, Kurtz and his colleagues were responsible for setting up dozens of experiments and research infrastructure that would be used by other scientists over the course of the year.
The nature of the field experiments that surrounded the ship speaks to the diverse expertise of the crew. Some of MOSAiC’s more far flung field sites were up to 30 miles away, accessible only by helicopter. Others took place thousands of feet above and below the ship, where dirigibles or underwater robots collected data and relayed it back to the surface.
Kurtz’s experiments were just a few minutes’ walk from the Polarstern. They were designed to measure changes in the ice’s thickness, density, thermal conductivity, and other properties, which will serve as a ground truth for polar measurements taken from space. The dynamics of the Arctic floe have a lot to tell us about our planet; Kurtz’s experiments are helping us decipher its language.
Being on the ice gave Kurtz a refreshed perspective of an area he could previously only appreciate from satellite data or the window of a plane, both in terms of the immense scale and barren beauty of the Arctic landscape, and what it means to study the ice.
“Science by its nature is very dry and technical, so you’re not necessarily thinking about why something is important when you’re solving an equation, you just do it,” Kurtz says. “But going to take these measurements to make sure we understand what’s happening and what it means for the future put a very different context on the work I do.”
Kurtz says he was struck by the realization that his two elementary school-aged children—who loved to hear stories about his polar bear interactions again and again—will likely never see what he saw during his trip. The Arctic is warming much faster than the rest of the world and its ice sheet is receding at an alarming rate. Over the past few decades it has lost enough winter ice to cover Alaska, Texas, and Montana combined, and many of the regions that used to stay frozen during the summer are now ice-free. Scientists are only just beginning to understand how the Arctic affects and is affected by climate change, but the work of Kurtz and other MOSAiC scientists will fill in a crucial gap in that knowledge.
Kurtz’s retired advisor Hoff adds, “One thing UMBC can be very proud of is the number of its graduates and alumni who are contributing to decision making and making important decisions about the most critical issues which will affect the planet.”
—By Daniel Oberhaus
Learn more about other ways UMBC staff and students are using their research to study and combat the effects of climate change.
Header Image: RV Polarstern in the Arctic. During the MOSAiC expedition the German research icebreaker Polarstern, which is operated by the Alfred Weggener Institute, drifts with the sea ice for a whole year, experiencing several months of polar night. Alfred-Wegener-Institute / Markus Rex (CC-BY 4.0)