Tag Archives: chemistry

UGA Skidaway Institute scientist to spend winter 2020 locked in Arctic ice

Cliff Buck

Spending the Christmas holidays and the better part of January and February on a ship frozen solid in the Arctic ice cap isn’t most people’s idea of a great way to spend the winter. However, University of Georgia Skidaway Institute of Oceanography scientist Cliff Buck is planning to do just that. Buck is part of a major, international research project named Multidisciplinary drifting Observatory for the Study of Arctic Climate or “MOSAiC.” The goal of the project is to sail the German ice breaker Research Vessel Polarstern into the Arctic Ocean until it becomes locked in the ice and leave it there for a year, all the while using it as a headquarters for scientists to study Arctic climate change.

Climate change is occurring at a higher rate in the Arctic than in other regions. That rate of change is not reflected well in climate change models, mostly due to the lack of year-round observations in the Arctic.

“We care about this because the Arctic is turning out to be one of the more sensitive parts of the planet when it comes to climate change,” Buck said. “It’s warming at rates much higher than other parts of the world, and as it warms, many things are happening, such as the reduction in the expanse of sea ice.”

Those changes have implications on the means and rates that materials flow into the region, which, in turn, affect plant and animal life. Buck’s role will be to monitor the atmospheric deposition of trace elements like iron. Trace elements appear in the ocean in minute concentrations — parts per billion or even parts per trillion. However, they play a key role in the growth of phytoplankton — the tiny marine plants that form the very base of the marine food web and produce approximately half the oxygen in our atmosphere. In much of the world’s ocean, it is the presence or scarcity of iron that regulates the growth of phytoplankton.

Buck and his colleagues hope to develop a better understanding of how trace elements make their way from the upper atmosphere to the ice cap. They can arrive either as little particles, floating in the atmosphere and settling like dust, or they can fall as part of a raindrop or snowflake.

“In the Artic, the composition and abundance of aerosols tend to vary seasonally which is the reason it is important to get a series of observations over a long time scale to see how deposition rates of these aerosols change over the course of a year,” Buck said. “We care about that because in areas removed from river input and other continental influences, atmospheric deposition can be the primary source of trace elements like iron for the surface ocean.”

Buck and colleagues from Florida International University and Florida State University will use a technique utilizing a radioactive isotope of beryllium, itself a trace element, to measure the rate of atmospheric deposition. Beryllium-7 is created only in the upper atmosphere by the exposure of nitrogen and oxygen to cosmic rays, and has a half-life of 53 days. By measuring the concentration of beryllium-7 in samples, Buck will be able to estimate the rate beryllium and other trace elements are being deposited on the surface.

R/V Polarstern
Photo credit: Stephanie Arndt/Alfred Wegener Institute

The research team will take turns working on the ship in shifts of two months at a time. As many as 40 to 50 scientists might be on the R/V Polarstern during each shift, collecting samples and making a wide range of observations throughout the year. Buck is tentatively scheduled to be on board from mid-December 2019 through mid-February 2020.

“I really have no one to blame but myself for being assigned a winter shift,” Buck said. “It is very difficult to make these measurements during the winter, so it is very important to us to insure those winter samples are collected properly. When I said that out loud, they said ‘so I guess you want to go in the winter.’”

Although locked in the Arctic ice cap, the R/V Polarstern will not be stationary. The area where the researchers anticipate the ship will be frozen is subject to a surface current called the Transpolar Drift which propels sea ice from the East Siberian Sea to the Fram Strait, off the east coast of Greenland. The R/V Polarstern could drift as much as 1,500 miles during its year locked in the ice cap.

“The Arctic Ocean is a very interesting place with a lot of wind and a lot of physics going on up there,” Buck said. “You may not perceive the movement, but you will be moving.”

Buck’s participation in the MOSAiC project is funded by a four-year, $350,412 grant from the National Science Foundation Arctic System Science Program.

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Skidaway Institute’s Diaz studies the tiny organisms with a big impact

Like many oceanographers, Julia Diaz is difficult to categorize. Is she a biologist, or is she a chemist? The answer is — a little of both. Diaz’s research interests lie where biology and chemistry meet.

“My absolute favorite thing in the world is looking at phytoplankton under the microscope,” she said. “And I am also very passionate about chemistry.

OLYMPUS DIGITAL CAMERA“Our chemical environment really shapes our health and impacts our climate and all kinds of natural resources. So I am interested in the intersection of those two parts of nature — how tiny microscopic life interacts with the invisible chemistry out there to shape the environment in some pretty big ways.”

Diaz joined the faculty of UGA Skidaway Institute of Oceanography in fall 2015 as a homecoming of sorts. She was raised in Alpharetta just outside Atlanta. She graduated summa cum laude from the University of Georgia with a degree in biology and then went on to earn a Ph.D. in earth and atmospheric sciences from Georgia Tech. Her postdoctoral work took her to Harvard University and Woods Hole Oceanographic Institution.

Diaz targeted science as her future from an early age. Her father is a retired Georgia State University professor, and her entire family was involved in education. Her brother is an astrophysicist, and she jokes that they study opposite ends of the universe—with her specializing in the very small while he studies the very large.

“I grew up talking about science with my dad, my brother and my mom,” she said. “It was always on my mind, and I was pretty good at it. It felt good to learn and to always be exploring new things.”

As an undergrad at UGA, her interest in science grew into a passion.

“I got into some really cool classes, where we basically spent two days out of the week staring down a microscope at pond water and it was just the coolest thing,” she said. “All these creatures that you would never imagine are there. It’s amazing — this whole other world that really drew me in.”

In graduate school, Diaz focused more on chemistry to complement her background in biology.

“I originally got interested in marine chemistry and biology because I was inspired by the fact that, billions of years ago, marine microbes created oxygen and other life-giving chemicals to make this planet the habitable place that it is,” she said.

Diaz’s work has taken her from the Caribbean to Antarctica.

“One of the best parts about this job is that it lets you see the world. Antarctica was the most amazing experience — you never get tired of seeing penguins,” she said.

Diaz with her penguin friends

Diaz with her penguin friends

“Personally, I never got tired of looking at Antarctic phytoplankton, either. They can attach to the underside of sea ice, making it look like it’s been dipped in coffee, but under the microscope, it’s like peering inside a jewelry box of gorgeous single cells, so many ornate shapes and vibrant colors. It’s just magical.”

Many of Diaz’s projects focus on phytoplankton — microscopic plantlike organisms that drift with the ocean’s currents. They form the base of the marine food chain and produce half of the oxygen in the atmosphere. Among other projects, she studies how starving phytoplankton obtain the chemical nutrients they need from seawater, and she attempts to identify the enzymes that drive those biogeochemical processes.

Diaz is also interested in how phytoplankton convert chemical elements into forms that can be harmful or beneficial to life, such as reactive oxygen species, or ROS, types of oxygen with additional electrons. They are produced in all living things as a byproduct of metabolism.

“ROS can be toxic, but they can also be very beneficial to life,” Diaz said. “They can serve as cell signals that promote growth and immune defense. Our own white blood cells produce ROS as a defense mechanism against invading pathogens.”

An important facet her work seeks to understand is how phytoplankton may use ROS to survive stressful situations, such as attack by predators. These ROS-driven processes may play a role in the formation and decline of giant phytoplankton blooms so large they can be seen by satellites.

She admits her work can be challenging to communicate outside of her field, because much of the research cannot be seen by the naked eye. However, she said, those invisible chemical processes are occurring in the ocean over sizeable areas and long time periods, and they produce large visible effects that shape our daily lives.

“From starvation to cell defense, a lot of the work I do relates to stress in the oceans — how marine life copes with stressful conditions, how stress changes the chemistry of the oceans and ultimately how that changes the environment on a global scale. The oceans are under increasing amounts of stress due to climate change, pollution and other human impacts, so I think this kind of research has an important place in the understanding of our changing planet.”

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