This story originally appeared in Columbia News.
Laramie Jensen grew up in Vermont, a landlocked state, before decamping to Minnesota, another landlocked state, for her undergraduate studies at Carleton College. She hadn’t thought about or spent much time on the ocean until an undergraduate academic advisor suggested that she apply for a summer research experience in Delaware, studying marine chemistry. That experience led her, eventually, to her current area of study, chemical oceanography.
Jensen spent most of last fall on a boat on the Arctic Ocean. She joined Columbia and Lamont-Doherty Earth Observatory, which is part of the Columbia Climate School, as an assistant professor of earth and environmental sciences in January. Jensen researches ocean metals, and the patterns of water flows between the Arctic and North Atlantic. Columbia News spoke to her about what led her to her field, what her research can tell us about the climate more broadly, and what it feels like to have a close encounter with a polar bear.
What does your work focus on?
I study metals in the ocean—things like iron, zinc, copper, manganese, nickel, cobalt, cadmium, and lead. Just like we need things like iron and zinc and copper in our own diet, phytoplankton, which are the algae that form the base of the food web in the ocean, also need these metals for optimal growth.
I look at the biogeochemical cycling of the metals in the ocean, and particularly in the Arctic Ocean, where we are seeing very rapid changes in both climate and ecosystem structure. I’m looking at the effects of those changes, both to understand the chemistry and biology of what’s happening, and to understand its effects on the atmosphere. I also examine broader questions about freshwater leaving the Arctic and how it circulates in the North Atlantic.
What are the broader implications of the research?
Phytoplankton absorb about half of the carbon dioxide from the atmosphere globally and they also produce about half of the oxygen that we breathe. So we really want to know things like how much they’re growing and which species are dominant. The amount of metals in the ocean really affects which species of phytoplankton thrive and which decline. They help algae grow, and, if there aren’t enough metals, they can also limit the amount of growth.
The research could also have implications for how we tackle climate change: There are currently proposals for geoengineering solutions like iron fertilization, for example, which would add iron to the ocean to help stimulate algae growth and remove carbon dioxide from the atmosphere. But there could be unintended consequences to that if there’s increased water discharge from the Arctic because of increased coastal erosion and permafrost thaw. The kind of research I do can give us a better understanding of all of these interconnected dynamics.
“In the Arctic you have to contend with polar bears… The longer you stay out on the ice, the closer the bears get.”
What got you started on this path?
I was a chemistry major in college. I really like inorganic and analytical chemistry. My undergraduate advisor suggested that I apply to a research experience for undergraduates in marine chemistry. It was a really cool project, and it stimulated my interest in applying chemistry to the natural environment. I fell in love with the idea of being out on a boat and then going back to a lab and analyzing your samples. I hadn’t known you could do that.
I found an advisor at Texas A&M, Jessica Fitzsimmons, who was working on metals in the Arctic and Antarctic oceans, and I decided to apply to graduate school to work with her. I got involved in graduate school with this larger global organization called GEOTRACES, which was co-founded by Columbia professor Robert Anderson. GEOTRACES aims to identify key elements and their isotopes that help us trace these metals across the oceans.
What are you teaching now?
I am assisting with the Environmental Science Senior Seminar class this semester, helping undergraduate students at Barnard and Columbia write their senior theses in Earth science and sustainable development. I plan to teach more courses related to marine biogeochemistry and polar oceanography at Columbia.
How will being at Columbia affect the direction of your research?
I was thrilled to be appointed to a position in the Department of Earth and Environmental Sciences because of the broad nature of the program and science conducted. I want to expand my scientific “toolkit” and learn to apply my favorite chemical elements to new questions at sea and on land, including paleo applications. There is a rich history of transformative earth science at Columbia and the Lamont-Doherty Earth Observatory. I can’t wait to see where that takes me and my trace metals.
Do you go to the Arctic often?
I go pretty much every year. Last year I was up there twice. I have three projects going on up there right now. I was up there for about two months in the fall for a research project funded by the National Science Foundation.
What do you like to do to stay entertained while you’re up there?
The first time I ever went out to sea was in the Antarctic and we had very limited internet. We’d get a digest of New York Times headlines every day, but you couldn’t even really send messages to people. Now, with satellite internet advances, you can download TV shows or movies, and the internet is pretty good. On this last expedition we were on a coast guard vessel with multiple, large gym spaces so we stayed in good shape. Every ship I’ve been on has a lounge area where you can congregate. We do cribbage tournaments. I play a lot of cards when I’m at sea.
Can you get out and walk on the ice?
It depends on the conditions of the ice. In the Arctic you also have to contend with polar bears. The members of the Coast Guard come down to the ice with us and are on bear watch. They stay positioned all around us with bear rifles. The longer you stay out on the ice, the closer the bears get.
How do you like living in New York City?
I grew up in a town of about 800 people. I never thought I’d live in New York City, but it’s fun. I spend a lot of time in the city’s green spaces, and a lot of time rollerblading. I go to Columbia’s Lamont-Doherty campus in the Palisades for work, so I also get to escape the city a bit. There are nature preserves up here. There are three turkeys outside of my window right now.
