This is a re-post from Yale Climate Connections by Kristen Pope
More than 300 scientists from 19 nations are engaged in planned two- to three-month stints locked in polar ice on the German icebreaker RV Polarstern. Over the winter, researchers face constant darkness, frigid temperatures plunging to -45 degrees Celsius, and the threat of hungry polar bears near their research camps.
With humanity in desperate need of data about the drastic, dangerous, yet mysterious changes that global warming is wreaking at the top of the world, the ship will lock itself in Arctic sea ice for a full year to facilitate the MOSAiC project (Multidisciplinary drifting Observatory for the Study of Arctic Climate).
“We’re in a new Arctic, and we don’t understand how things work in this new Arctic, so that’s one of the things that’s most exciting, and that’s the overarching science question of MOSAiC: What are the causes and consequences of an ice-diminished Arctic Ocean?” says Donald Perovich, professor at the Thayer School of Engineering at Dartmouth and co-lead of the MOSAiC sea ice team. “And I think trying to answer that question for me is the most exciting part of MOSAiC. The Arctic is a lot different than when I started doing this.”
Perovich saw Arctic sea ice for the first time in 1979 when he was a 28-year-old researcher. It was right around the time satellites started tracking sea ice. The minimum Arctic sea ice extent recorded in 1979 was 2.7 million square miles – a number that plunged to 1.32 million square miles in 2012, a sign of drastic melting.
“The ice extent has changed,” Perovich says. “There’s less, particularly in the summer, and a very basic property of the ice has changed. There used to be more older, thicker ice, and when I talk about sea ice, old is like four or five years old.” Perovich explains that ice changes as it ages, becoming thicker and more robust over time. “That really old ice has decreased greatly in the 40 years since I’ve been working on the ice to where now it is just a few percent of the ice cover, and a consequence of that is the ice now is thinner and less robust.”
The loss of that ice affects coastal communities that had been protected from fall storms by a buffer of sea ice. That sea ice also protects those communities from coastal erosion. Now, communities are exposed to harsh waves and storms, and some areas are crumbling into the ocean. Perovich also points out that the loss of sea ice makes Arctic oil and gas extraction more accessible and increases the feasibility of northern shipping routes and increased tourism, both of which are likely to impact the area and its ecology.
Melting sea ice doesn’t just affect those who live in the Arctic. The effects of an ice-diminished Arctic ocean range are global in scale and hinge around a process called Arctic amplification, which throws the jet stream off its normal path and leads to extreme weather events. These altered patterns lead to heat waves, droughts, and extreme wildfires, among other impacts. As sea ice melts, the ocean absorbs more sunlight for an easily explained reason: Dark sea water absorbs more solar energy than light ice does, further increasing temperatures and inducing a cycle that further intensifies the melting.
“We see that there’s less and less ice, and we first want to understand what’s driving those changes,” Perovich says. He says his research team is particularly interested in learning about how snow behaves, including how wind moves it, how it builds up in winter, and how it melts in summer. He is scheduled to join the fifth leg of the journey, from June to August 2020, a time period closely aligned with another research interest: how sunlight interacts with sea ice and melt.
“The big opportunity of MOSAiC is to get an annual cycle, to be there for the whole year to see this whole movie,” Perovich says. “There’s a lot of experiments done in the Arctic that are really good, but typically they’re for shorter time periods, months, a couple months in this place, a couple months over here. But here we get to be in an area for a whole year and see how things evolve over time, and we also want to see how they evolve spatially – there’s a lot of variability in the ice cover.”
“It’s the biggest sea ice experiment that’s ever been done,” Perovich says.
The ambitious project aims to study the new Arctic as scientists focus on five main research categories: atmosphere, sea ice, ocean, ecosystem, and biogeochemistry. They will study everything from zooplankton to atmospheric mercury deposition and explore how systems interact.
MOSAiC isn’t a completely novel idea – scientists have held year-long drift ice experiments in the past. “Drifting Station Alpha” was a 1957-1958 project held in honor of the International Geophysical Year. Then came the Arctic Ice Dynamics Joint Experiment in the 1970s, and SHEBA (Surface Heat Budget of the Arctic Ocean) in 1997-1998.
In September 2019, the first group of scientists set sail from Tromsø, Norway, and in early October they confirmed the ice floe where the project would take place: a 2.5 by 3.5 kilometer floe located at 85 degrees north and 137 degrees east. Using specially designed metal anchors, they affixed the ship to the ice, and it will drift with it over the next year.
Summer ice melt increased the researchers’ challenge of finding a suitable floe. Using satellite images, the team located 16 potential floes, further scouting via icebreaker, helicopter, snowmobile, and on foot. They collected ice core samples and charted ice thickness with electromagnetic sensors and helicopter-based laser scanners before agreeing on a specific floe. It contains an area with fairly stable ice and also has areas with thinner, more unstable ice characteristic of the “new Arctic.”
In an October 4 press release, MOSAiC expedition leader Markus Rex from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, said, “It may not be the perfect floe, but it’s the best one in this part of the Arctic and offers better working conditions than we could have expected after a warm Arctic summer.”
Finding the best ice floe to set up camp was only one of many logistical endeavors in the extraordinarily complex project. Spearheaded by the Wegener Institute’s Helmholtz Centre, MOSAiC took around 10 years to plan and is expected to cost more than 140 million Euros, about $155-million.
Chris Polashenski, research geophysicist at Cold Regions Research and Engineering Laboratory at Dartmouth’s Thayer School of Engineering, has been working on MOSAiC for nearly a decade. He says the idea first came about when a group of scientists discussing their work realized they shared a data gap: the central Arctic.
It is prohibitively expensive for any one project to spend a year collecting data there, so researchers decided to collaborate to find a solution. The scientists began planning a joint international expedition to collect and share data: They spent years holding workshops; planning; sorting out the key questions to address; figuring out funding; and developing a science plan.
“Some people would complain that it takes a decade to put something like this together, but I actually would say no, that’s how much time it takes to do it right,” says Polashenski, who is to join Leg 4 from from mid-April to late June 2020.
Polashenski has two specific science goals for his work with MOSAiC: studying the thermal conductivity of snow, and analyzing how wind moves ice and how pieces of ice interact. However, in addition to collecting their own data, the scientists will also spend time collecting data for colleagues who are not onboard.
“We’re all covering for each other,” says Polashenski. “I’ll only be on the boat for 2.5 months, but I need someone to take my samples when I’m not there, and they need me to take their samples when I’m there, and I need to make sure that we both understand each others’ projects.”
In addition to working together to make sure all samples are acquired, scientists also coordinate to make sure they have all the equipment they need without too much overlap. “We can also look and see, well, we’ve got 10 people bringing the same thing, and we only need five of those, so we’ll keep the other five in a warehouse in Norway in case we need them later,” Perovich says.
Actually getting people and equipment to the Polarstern is another huge logistical challenge. Depending on the time of year, and state and thickness of the ice, short-field jets, icebreakers, and long-haul helicopters could be used to ferry personnel and supplies on and off the vessel.
Once safely on the ice, scientists spend long days – sometimes over 12 hours – collecting measurements and data at stations on the ice while guards keep watch for polar bears. After a day’s work is done, they retreat to the ship for the night. Though there isn’t a lot of personal space, the ship provides warm berths, hot meals, and camaraderie. And unlike conducting field work in tents, researchers don’t have to worry about the ice breaking up under a tent at night or a polar bear approaching their camp while they sleep.
To prepare for the rigorous fieldwork, participants have attended training sessions ahead of their deployments to the ice. While many MOSAiC researchers are veteran polar scientists, others are graduate students and early-career scientists less experienced with harsh polar conditions, so they wanted to make sure everyone was ready. The researchers also used those opportunities to field test equipment and work out any hiccups ahead of time. Polashenski led a training session in Utqiagvik, Alaska (formerly known as Barrow).
“[MOSAiC] is a big commitment,” Polashenski says. “You’re going two and one-half months to the central Arctic, and there’s no real way to get home after four days if you don’t like it. We took everyone up to [Utqiagvik] and had them all out on the sea ice and out in the wind and the cold and testing their instruments and seeing what broke and what didn’t in a much lower-stakes environment where we could go back into a heated building at the end of the day, and they could go home in a 737 at the end of the week.”
During the training, Polashenski helped colleagues practice using a variety of equipment and navigating on ice, as GPS is unreliable on drifting floes. He also wanted to get people used to spending all day outside in -30 temperatures, allowing time to fine-tune equipment and clothing selections. The team also focused on troubleshooting a variety of problems they may run into in the field, such as a tipped-over snowmobile. “I want them to not be going up to MOSAiC and encountering something for the first time,” Polashenski says.
After the field training, scientists are even better prepared to conduct their research and ultimately leave a legacy of data – which they say is the most important part of the project.
“One of the things about MOSAiC is that we all have our special projects and our interests and you can already get excited about the findings you expect to make and get even more excited about the unexpected things that you’ll encounter,” Perovich says, “and we all realize that the data is the legacy.”
“We’re creating a data set that hopefully people will be using 20 or 30 years from now, and we put a lot of effort into making sure that we come up with a data set that’s archived with all the data you need to understand the observations we’re going to be making.”
Posted by Guest Author on Thursday, 19 December, 2019
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