Carbon cycling is an essential part of life on the planet. Plants and animals use the element for cellular growth, it can be stored in rocks and minerals or in the ocean, and of course it can move into the atmosphere, where it contributes to a warming planet.
A new study led by Dr. Megan Behnke, a former Florida State University doctoral student and Woodwell Polaris Project participant who is now a researcher at the University of Alaska, found that plants and small organisms in Arctic rivers could be responsible for more than half the particulate organic matter (a carbon-rich nutrient) flowing to the Arctic Ocean. That’s a significantly greater proportion than previously estimated, and it has implications for how much carbon is sequestered in the ocean versus how much moves into the atmosphere.
Scientists have long measured the organic matter in rivers to understand how carbon cycles through watersheds. But this research, published in Proceedings of the National Academy of Sciences, shows that organisms in the Arctic’s major rivers are a crucial contributor to carbon export, accounting for 40 to 60 percent of the particulate organic matter—tiny bits of decaying organisms—flowing into the ocean.
“When people thought about these major Arctic rivers and many other rivers globally, they tended to think of them as sewers of the land, exporting the waste materials from primary production and decomposition on land,” said Dr. Rob Spencer, a professor in the Department of Earth, Ocean and Atmospheric Science at FSU, and collaborator on the paper. “This study highlights that there’s a lot of life in these rivers themselves and that a lot of the organic material that is exported is coming from production in the rivers.”
Scientists study carbon exported via waterways to better understand how the element cycles through the environment. As organic material on land decomposes, it can move into rivers, which in turn drain into the ocean. Some of that carbon supports marine life, and some sinks to the bottom of the ocean, where it is buried in sediments.
The study was supported by the Arctic Great Rivers Observatory, and it examines six major rivers flowing in the Arctic Ocean: The Yukon and Mackenzie in North America, and the Ob’, Yenisey, Lena, and Kolyma in Russia. Using data collected over almost a decade, they built models that used the stable and radioactive isotope signatures of carbon and the carbon-to-nitrogen ratios of the particulate organic matter to determine the contribution of possible sources to each river’s chemistry.
Not all particulate organic matter is created equal, the researchers found. Carbon from soils that gets washed downstream is more likely to be buried in the ocean than the carbon produced within a river. That carbon is more likely to stay floating in the ocean, be eaten by organisms there and eventually breathed out as carbon dioxide.
“It’s like the difference between a french fry and a stem of broccoli,” said Dr. Behnke. “That broccoli is going to stay in storage in your freezer, but the french fry is much more likely to get eaten.”
That means a small increase in a river’s biomass could be equivalent to a larger increase in organic material coming from the land. If the carbon in that organic matter moves to the atmosphere, it would affect the rate of carbon cycling and associated climate change in the Arctic.
“I always get excited as a scientist or a researcher when we find new things, and this study found something new in the way that these big Arctic rivers work and how they export carbon to the ocean,” Dr. Spencer said. “We have to understand the modern carbon cycle if we’re really going to begin to understand and predict how it’s going to change. This is really relevant for the Arctic at the rate that it’s warming and due to the vast carbon stores that it holds.”
The study was an international endeavor— a feature that, Dr. Behnke notes, is critical to Arctic work, especially as climate change advances.
“That pan-Arctic view of science is more important than ever,” Dr. Behnke said. “The changes that are occurring are far bigger than one institution in one country, and we need these longstanding collaborations. That’s critically important to continue.”
Polaris Project alumni and early career scientists, Aquanette Sanders and Edauri Navarro-Peréz were awarded the 2022 John Schade Memorial scholarship. The fund, established to honor Dr. Schade’s unwavering dedication to mentoring young scientists, recognizes two students per year who are pursuing higher education and reflect Dr. Schade’s values of mentoring, education, leadership, equity in the sciences, and advancing Arctic and environmental science to mitigate climate change.
“The purpose of the fund is to support the next generation of scientists who are making a lifelong career and personal commitment to activities that reflect and demonstrate Dr. Schade’s values,” said Dr. Nigel Golden, a postdoctoral researcher at Woodwell and coordinator of the fund. “We were profoundly impressed with this round of applications. All of the applicants for the scholarship were exceptional early-career scientists who are doing timely and important research, and whose career trajectories have been impacted by their mentorship through Dr. Schade, or through their mentors who worked with him. For Aqua and Edauri, what really helped to set them apart was a demonstrable commitment to creating spaces to ensure the success of scientists from a diversity of backgrounds.”
Aquanette Sanders is a Masters student at the University of Texas, Austin, pursuing a degree in Marine Science. However, as a Polaris participant, Sanders’ research focused on the soil. She studied greenhouse gas fluxes from thermokarst features— depressions and bumps in the tundra landscape formed by permafrost thaw. Sanders studied how emissions of carbon dioxide, methane, and nitrous oxide differed between these features and undisturbed areas of tundra.
Sanders’ career so far has taken her from an undergraduate research program with Maryland Sea Grant, to a SEA Education cruise to the Sargasso sea, to the Simpson Lagoon on Alaska’s North Slope, where she is currently researching groundwater nutrient flows as they change with thawing permafrost. For Sanders, the experience with Polaris affirmed her interest in climate change and Arctic science.
“The Polaris Project was my gateway into Arctic science,” says Sanders. “Seeing the effects of permafrost thaw first-hand, with the large amount of thermokarst features in the Yukon-Kuskokwim Delta, confirmed that my research interest in greenhouse gasses and nutrient cycles— a topic that still has so many rising questions that need to be answered.”
Sanders says she is always looking for her next step forward in research. She plans to pursue a dual doctorate in veterinary medicine and research after completing her masters degree. She wants to combine her background in chemistry and biology to understand how changes in nutrients will affect aquatic animals at the top of the food web.
“My research is motivated purely by the eagerness to learn more. As I find new results, I ask more questions that eventually lead to more experiments or hypotheses. This keeps me excited and ready for present and future research,” says Sanders.
Edauri Navarro-Pérez is Ph.D. candidate at Arizona State University, with a background in soil, root ecology, and drylands restoration. As a Polaris student, Navarro-Pérez investigated whether there were differences between emissions coming from burned and unburned areas of the tundra. Her work contributed to a body of research examining how fires are affecting chemical processes in tundra soils— specifically respiration, which emits carbon and nitrogen. For her, Polaris was an opportunity to gain experience with field methods.
“Polaris contributed a lot to my knowledge in terms of how soil science is done in the field, as well as the process of the scientific method— from developing my own question to seeing the results of my work,” Navarro-Pérez said.
From Polaris, to working as an undergraduate lab technician, to conducting research in Belize and Costa Rica, Navarro-Pérez is led by her curiosity. She is especially interested in the way soil connects to our daily lives, and how understanding the interactions between plant roots and the soil in which they’re growing can lead to a deeper understanding of climate change.
“Understanding how restoration projects can affect plant development and how plants can affect soils in the longer run, through decomposition and soil respiration, can be pertinent to environmental planning for climatic issues,” said Navarro-Pérez.
Navarro-Pérez said she feels grateful that an environmental scholarship supporting Latina and Latino students enabled her to earn her undergraduate degree. She now hopes that her future career will involve research, mentoring, and teaching, as well as exploring her research topics through art and literature which provides a different frame for examining the world around us.
Both recipients will receive funding to continue their education and pursuit of science, mentorship, and equity, encouraging a new generation of Arctic scientists working to change the world.
The Polaris Project began in 2008 as a way to shepherd a new generation of Arctic and climate scientists into their careers. Each summer, Woodwell has selected a cohort of capable and motivated students, bringing them on a two-week field excursion guided by leaders in the field of Arctic science. Students explore the landscape, design a research project, and collect data, before returning to the Center to analyze their results.
In the United States, Women make up only 28% of the STEM workforce—a trend that is reinforced by lack of support for women and girls to explore a career in science. Polaris aims to combat this. For the women of Polaris, the experience has provided valuable mentorship, built confidence in their skills, and sparked their motivation to forge ahead into their future as scientists. Alumnae of the Polaris Project have gone on to pursue doctorate degrees in climate research, influence climate policy, and some have even returned home to the Center. Here, we meet just a few of the impressive women of Polaris.
Dr. Claire Griffin was part of the very first Polaris expedition. In the early days of the program, the field site was located in the far northern region of Kolyma, Russia. She sampled lakes and used remote sensing to map organic matter in the Kolyma River and its major tributaries. Her research grew into a published paper co-authored with Clark University Professor of Geography, Dr. Karen Frey, and Woodwell’s Acting President and Executive Director, Dr. Max Holmes.
Dr. Griffin’s experiences in the Polaris Program have guided her throughout her career. She recalls one afternoon walking back from the homemade lab where students were analyzing their samples, talking with one of the expedition’s leaders, Dr. John Schade.
“I was saying that I found pipetting to be pretty meditative in some ways,” Dr. Griffin says. “You get into a rhythm and the lab work can be kind of soothing. And he said that one of the things in science is that no matter what you’re doing, there is going to be something that is kind of boring, so find the tedium that you like and be able to do that.”
Dr. Griffin says she thought a lot about this when she was making decisions about where to go next. Considering two graduate programs, Dr. Griffin chose the direction of lab chemistry because she couldn’t see herself enjoying the tedium of counting tree rings. She has been working on aquatic chemistry ever since, studying how terrestrial material moves from land into aquatic systems— specifically carbon and nitrogen.
“I would not be doing what I’m doing today if I had not gone through Polaris. The most effective way to learn science is to actually do it, and the learning-by-doing model that Polaris espouses is something that definitely had an effect on me.”
Dr. Griffin wants to share that model with students of her own. She is currently looking for faculty positions at teaching-focused colleges.
“I enjoy teaching and talking about science,” Dr. Griffin says. “If we are going to enact climate change policies for the better, then we need to be able to reach students who are not going into the environmental sciences.”
Throughout her career, Dr. Blaize Denfeld has made her decisions based on spark.
“I feel like every step of the way, something I’ve done has sparked something in me that I realize, ‘maybe this is the next step that I want to pursue.’ So it’s been an interesting journey starting with the Polaris project to today,” says Dr. Denfeld.
After completing the Polaris Project and her undergraduate studies, she applied for a Ph.D. program in Sweden, thinking “I was in Siberia for a month and a half, I can live in a foreign country for a few years.” It was there she felt a spark for the aspects of science that involved collaboration and coordination, so she accepted her next position at NASA’s Earth science division. After NASA, she felt the spark for combining science and policy and moved on to the US Global Change Research Program, and finally, her current position as Deputy Director of the Swedish Infrastructure for Ecosystem Science (SITES). SITES runs nine ecological research stations across Sweden that monitor the Arctic and Boreal environment. Some of the stations contain ice records that extend back to the 1940s, which Dr. Denfeld says provide a powerful image of just how much the climate is changing.
In her current role, Dr. Denfeld coordinates scientific collaborations across all SITES’s research stations. For Dr. Denfeld, the best part of her position, and of all the jobs she’s held, has been her fellow scientists.
“I think for me it always comes back to the people and the collaborations. Of all the positions I’ve had, the thing I enjoy the most is getting to work with passionate people that are really intelligent and have really good ideas,” says Dr. Denfeld.
Dr. Denfeld says that, whatever direction her career takes next, she hopes to be a model for other women in STEM.
“As my career has progressed, I’ve benefited from really strong women in science, and so I feel a stronger passion now for paying it back for all the female scientists that helped me get to where I am now.”
Emily Sturdivant joined the 2011 Polaris expedition to Siberia with an interest in GIS and an open mind about where the experience might lead. Her project involved collecting data on carbon fluxes with a homemade flux chamber that she would later use to ground truth satellite data observations.
“I would go out to a patch of water, anything from a tiny stream to a lake, tip my bucket upside down onto the water and track the change in gas concentration inside the bucket as I measured wind speed and other variables in the surroundings,” Sturdivant says.
Sturdivant recalls the days of field work alternating between chaos and tranquility.
“One of my favorite memories is of when another participant and I headed out to collect samples at a lake across the river from the barge where we were bunked. They dropped us off with an inflatable boat that, along with my bucket and other equipment, we hauled through the bushes and pumped up with one foot or the other sinking through the vegetation,” Sturdivant says. “After the chaos of setting up, drifting on the lake as we collected our measurements in the midst of the wilderness was so peaceful.”
Though Sturdivant didn’t carry on with Arctic research after graduating from Clark University, she still carries what she learned from the experience into her work as a Research Assistant and Geospatial Analyst Consultant at Woodwell where she works on forest carbon analyses.
“That experience became an invaluable reference as I continued in science and remote sensing. Now as I work with pixel values and ground data collected by others, I understand the work and complexity involved in collecting those data,” says Sturdivant.
As she grows in her career, Sturdivant says she is looking forward to being a positive influence on all her fellow colleagues.
“I want to keep being involved in the institution and mentorship,” Sturdivant says. “As Polaris did for me, I want to help others find moments of inspiration and guidance.”
The universe seemed to conspire around Darcy Peter to bring her to the Polaris Project. The application was forwarded to her by professors and friends alike and she soon found herself on the 2017 expedition examining greenhouse gas emissions from water bodies in Alaska’s Yukon-Kuskokwim Delta.
Peter is an Koyukon & Gwich’in Athabascan from the village of Beaver, Alaska and during that summer, she noticed the Polaris Project did not have much interaction with the Indigenous communities nearby. She brought this feedback to Woodwell Arctic Program Director Dr. Sue Natali.
“I said if Polaris is going to continue for years, we need to have a relationship with the people, and if we are going to train the next generation of Arctic scientists, we should be making sure the research questions we are forming are impacting Alaska Natives in a positive way,” says Peter.
Peter returned as a student mentor in 2018 and worked with Dr. Natali to implement changes to the program that would build stronger relationships with locals in the community of Bethel where Polaris participants stay before heading out to the field site.
Peter organized a meeting where scientists and students could listen to the concerns of community members and apply them to students’ projects. Peter also went on the local radio station to promote the meeting and spearheaded the creation of a newsletter about the project that was translated into Yupik, the traditional language spoken in the region. She volunteered her time in 2019 to lead the community meeting in Bethel again, and joined Woodwell full-time as a Research Assistant in 2020.
“The first community meeting in Bethel was very impactful—seeing seasoned, more experienced scientists have questions for the community… I think it really painted the picture for a lot of the scientists traveling with us that year of the power their research has to truly help people,” Peter says.
Peter is now the face of Woodwell in Alaska, working from Fairbanks surrounded by friends and family to continue building bridges between Woodwell and Alaska Native communities and non-profits, as well as facilitating the Center’s ongoing Arctic fieldwork. She says she intends to dedicate her career to ensuring science is conducted ethically, in a way that benefits people.
“All research has the power to affect change,” Peter says. “What good is research if it only benefits other researchers? I want to keep serving Alaska Native communities and amplifying the voices of my people and my relations, whose voices have been put down their entire lives.”
Dr. Bianca Rodríguez-Cardona was an experienced Arctic researcher by the time she joined Polaris in 2017. She had been conducting her Ph.D. research on how fires influence stream chemistry in Russia’s Central Siberian Plateau when she heard about the program from Dr. John Schade, one of Polaris’s founding faculty members, at an AGU meeting, and he convinced her to apply.
Dr. Rodríguez-Cardona was confident in her field skills when she arrived in Alaska that summer. But the tundra of the Yukon-Kuskokwim Delta was different from the boreal forests of her field site in Siberia. Flowing water was much harder to find and she spent days hiking in search of a stream to take her measurements. When she did eventually find one, adding the carefully measured mix of salts she uses to track how nutrients flow through the water, they slipped by so fast she couldn’t jog downstream quickly enough to take a second measurement.
“I was sitting in mud up to my elbows and just thinking ‘this can’t be happening.’ I totally freaked out,” Dr. Rodríguez-Cardona says.
But she had been hiking that day with Dr. Schade, who helped her calm down, reassess the situation, and figure out how to get a second measurement with the supplies she had left. She looks back on that moment as a lesson in inner strength.
“We limit ourselves in whatever we think we can do until we’re there and we have to do it. It’s either now or nothing.” Dr. Rodríguez-Cardona says. “The Polaris Project helped to show me that I’m a lot more capable, stronger, and resilient than I think I am.”
Dr. Rodríguez-Cardona returned to Alaska as a mentor in 2019 and went on to a postdoctoral position at the University of Québec at Montréal. She hopes to find a permanent position after her postdoc that keeps her working and learning in the Arctic.
“I never imagined I’d be an Arctic scientist, but I’ve spent four summers now in the Arctic and Boreal regions. So, there is something to be said about chances and serendipity.”
For Natalie Baillargeon, 2018 was full of new experiences— it was her first year in Polaris, her first summer research experience, her second ever plane ride, and her first time going camping. But it was not her last. Polaris sparked her passion for ecological research.he returned again in 2019, but to a very different Arctic.
Record-breaking heat, rolling thunder, and dry lightning storms—in Bethel, the heat literally shattered the thermometer.
“There were days where Polaris leaders had to call days short due to fieldwork being dangerous,” Baillargeon says. “To be doing fieldwork in the Arctic and have to worry about heatstroke is not normal. It was sad and depressing.”
Baillargeon returned back to her college studies, determined to carry the research she began with Polaris through to its conclusion. She was examining the short- and long-term impacts of wildfires on vegetation. After four long years, through transferring colleges and moving her lab twice in the middle of the pandemic, Baillargeon recently submitted her paper for publication; her results show sustained impacts of wildfire on the ecosystem.
She began working at Woodwell Climate, as External Affairs Coordinator—before she graduated—and joined full time in June of 2021. According to Baillargeon, seeing the smoke of wildfires clouding the camp, and feeling the unusual heat of 2019 clarified her desire to affect change through policy as well as science.
“I actually think that 2019 Polaris was another pivotal experience for me because it reinforced my desire to work more on climate policy. I want to help make change instead of documenting the destruction of ecosystems.”
Ellen Bradley’s drive to study climate science comes from her Indigenous background. She is Tlingit and was searching for research opportunities close to her homelands when she found Polaris. During the summer of 2019, she marveled at the heat and smoke of a record-breaking season, listened to the concerns of the local communities in Bethel, and played the informal role of an Indigenous educator among her fellow students. Her experience solidified her desire to not only conduct research but to add an Indigenous voice to it.
“My passion about all of this, climate research, climate communication, science communication, comes from my being Tlingit, from my Indigenous background, from my connection to the land, and knowing that the actions that have caused us to be where we are have come from colonization,” Bradley says. “If we are going to solve something like climate change, we are going to need the assistance of the Indigenous people who have lived in these places for, in many cases, over 20,000 years.”
Bradley based her project on the concerns she was hearing from community members around fishing, and used phytoplankton as a proxy for the health of aquatic ecosystems. She intended to return to carry on this research in 2020, but the pandemic postponed expedition plans. Instead, Bradley graduated from Gonzaga into a world altered by COVID-19
Searching for her next step, she got involved in the winter sports community and began skiing for outdoor advocacy groups. She is an athlete for NativesOutdoors, Protect our Winters, and Deuter, as well as a ski ambassador for Crystal Mountain, Washington.
“I know I want to keep skiing as part of my career, using skiing to tell stories about Indigenous people’s joy on the landscape and why outdoor recreation is important for our fight against climate change,” Bradley says.
She began work at Woodwell as a research assistant for the Arctic program in 2021 and she will return to Alaska in 2022 with the other 2020 Polaris students. When she looks towards the future of her career, Bradley says she wants to use the opportunities she’s had to represent Traditional Ecological Knowledge in the climate space.
“I’ve had a lot of privilege to go to school and I’m also really nerdy about science, so it just feels like the best way for me to use the tools I have,” Bradley says. “Incorporating my values into science is helpful to more than just myself and my passions. It’s a voice that has to be out there, or it won’t exist.”
Alma Hernandez was accepted into the Polaris Project just before the world closed down due to COVID-19. In the uncertainty following lockdowns and rising cases, it became clear that the 2020 cohort wouldn’t be able to travel to the Arctic. Polaris, like everything that year, went virtual.
Though the field components of Polaris were postponed, Hernandez was still able to join Zoom meetings with other students and project mentors. She found the meetings just as meaningful, talking with others whose passions and backgrounds differed from her own, but converged around climate and the environment. Her interests lay in the unique Arctic soil that holds a wealth of information about our Earth’s changing climate.
“The composition of Arctic soils is really unique. They are extremely affected by global warming and have long-term implications as they release more greenhouse gasses that contribute to climate change,” says Hernandez.
Since the completion of the program, Hernandez graduated from University of Texas, El Paso, and has been accepted to a Master’s program at the University of New Hampshire. She was also the recipient of the NSF’s Graduate Research Fellowship award and Woodwell’s own inaugural John Schade Memorial Fund award. Hernandez says she feels indebted to the mentorship she has received from Polaris.
“There were many instances when I felt overwhelmed by the thought of not having the qualifications to apply for graduate school or fellowships. I almost gave up, but Sue [Natali] and the Polaris Alumni were all so encouraging. My success in these applications wouldn’t have been possible without their support,” says Hernandez.
Members of the 2020 cohort will be completing their field experience this summer. Hernandez is looking forward to her long-awaited trip to Alaska, excited to finally see the Arctic soils she has been studying so diligently. After that, she plans to complete her master’s degree and, perhaps after a well-earned break from school, earn a Ph.D.
“I want to be able to contribute at least a little portion of knowledge to serve people in the future. My dream was always to be a researcher, and I plan to keep pursuing this goal.”