The Roles of Seasonality, Silicification, and Alteration in Nitrogen and Silicon Isotope Paleo-proxy Variability

The chemistry of fossil diatoms, specifically their nitrogen and silicon stable isotope signatures, reflects past changes in surface nutrient sources and uptake. Changes in sedimentary diatom nitrogen and silicon isotope values from the Southern Ocean record to what degree ocean biology consumed nutrients in the surface ocean through time. The proposed work will address gaps in our understanding of how the diatom proxies record surface nutrient conditions. This work will ultimately improve our understanding of global-scale climate change in the past and contextualize future change. The project will foster the careers of early career scientists, impact education through training of students and incorporation into course work, and translate science methods, goals, and results of this project to novel audiences through art.

Participants Involved in This Project

Amanda in a classroom

Amanda McBride | Educator Fellow

Linus Pauling Middle School | Corvallis, OR
Kiley in front of a cliffside

Kiley Preheim | Educator Fellow

Chisholm Middle School (USD 373) | Newton, Kansas
Becky in front of a white background

Becky Robinson | Researcher Fellow

University of Rhode Island | Narragansett, RI

From the Blog

The bluest blue backdrop against a relentless twenty-four hour sun
The Power of Collaboration
I thought I had seen all of the colors of blue before my trip to the Far North. After all, I teach about the electromagnetic spectrum and the active and passive sensors that scientists use to understand our changing planet. And yet. There were blues in Kalaallit Nunaat that I had never seen before. While photographs don’t really capture the vibrancy of the colors, or the feeling of being there, they are a starting point for conveying what I mean.
Photo collage showing different kinds of fish
A Day in the Life
Polar STEAM brought me to Utqiaġvik in collaboration with Dr. Julia York from the University of Illinois. Dr. York’s post-doctoral work is investigating how Arctic fishes, specifically Iqalugaq (Boreogadus saida, Arctic Cod) and Uugaq (Eleginus gracilis, Saffron Cod), physiologically sense and adapt to the freeze thaw cycles that dominate the Arctic throughout the year. Unlike
Jeanette poses in front of a whale skull
A Day in the Life
My whirlwind polar adventure is coming to an end. After a very short 10 days (ALL DAY as the sun has not set in Alaska since mid-May), I find myself spending my last few hours in town reflecting on my experience both with the people as well as the research I helped with, all while admiring the tundra. Polar STEAM brought me to Utqiaġvik in collaboration with Dr. Julia York from the University of Illinois. Dr. York’s post-doctoral work is investigating how Arctic fishes, specifically Iqalugaq (Boreogadus saida, Arctic Cod) and Uugaq (Eleginus gracilis, Saffron Cod), physiologically sense and adapt to the freeze thaw cycles that dominate the Arctic throughout the year. Unlike some of the Antarctic fishes that Dr. York focused on during her PhD, Arctic cod experience a wider range of temperatures throughout the year, from freezing ocean water (28.4°F; -2°C) in the winter to up to mid-40s°F during the summer. Fishes are the same temperature as their environment and environmental temperature fluctuation means that during times of the year fishes must either swim away from the freezing water or adapt mechanisms to keep from freezing.
The team using the conductivity, temperature and depth tool on board the ship
A Day in the Life
The US academic research vessel RV Neil Armstrong departed from Nuuk, Greenland in early October. On the first leg of our journey, the science team’s initial purpose was to collect water samples and previously deployed instruments along a line of moorings at the southern entrance to Baffin Bay, a gateway between the Arctic and the north Atlantic. This line stretches from Sisimiut, on the west side of Greenland, to just off Cape Dyer, near the Canadian coast. 
The Power of Collaboration
Our plane glides through the Endicott Mountains of the Brooks Range as we make our final descent into Anaqtuuvak. Accessible only by plane, Anaktuvuk Pass (“the place of caribou droppings”) is located 250 miles northwest of Fairbanks and is home to the only community of inland Iñupiat, Nunamiut, people [1]. Below, icy blue glaciers feed into a winding network of streams that snake through dense, green tundra and low-lying willows that line the banks of the Anaktuvuk River. From the air, the tundra is a verdant forest, but once on the ground the trees and shrubbery are no taller than 5-6 feet. The village stands out like a colorful flower within the greenery, blooming into view as we enter the valley. In Anaktuvuk, the roots of plants and people alike extend down into permafrost, the lifeblood of the ecosystem and holder of history.