On a larger scale, anthropogenic climate change is drastically disturbing ocean temperatures and acidity, the sustainability of glaciers, the health of ecosystems and sea-levels. In fact, the Canadian Arctic is warming at four times the rate of the rest of the planet, making it indispensable to study Arctic waters to understand the impact of climate change on this critical region in the Earth system.
Baffin Bay is an Arctic marginal sea located between Baffin Island and the west coast of Greenland. This region provides cold and salty waters to the North Atlantic Ocean. Here, deep water is formed that acts as an engine driving global deep ocean circulation. Thus, Baffin Bay has been the primary target of numerous studies conducted by oceanographers and environmental scientists, including Sara Zeidan, a MSc graduate supervised by Professor Brett Walker.
Sara’s research aimed to determine a revised residence time for Baffin Bay Deep Water (BBDW). In other words, she wanted to how long deep water stays in the bottom of the basin before mixing back up and interacting with the atmosphere. This residence time informs our understanding of how substances, such as carbon and nutrients, can be stored in BBDW on longer timescales. She accomplished this by measuring stable carbon isotopes (δ13C) and radiocarbon ages (as Δ14C) in the water using Isotope Ratio Mass Spectrometry (IRMS) and Accelerator Mass Spectrometry (AMS), respectively. Sara estimated BBDW resides for 360-690 years, suggesting carbon can be stored in deep Baffin Bay for centuries. These findings help constrain the important role Arctic marginal seas can play in partially mitigating climate change. If for example, warming leads to greater export of surface carbon to depth, this atmospheric carbon will be stored for centuries in Baffin Bay. In addition, Sara’s study contributed greatly to our understanding of the oceanographic significance of Baffin Bay.
Sara’s results – the first ever recorded and published radiocarbon measurements in Baffin Bay – were presented at the Arctic Change 2020 Conference and at the ASLO 2021 Aquatic Sciences Meeting. She also earned a NSERC Alexander Graham Bell Canada Graduate Scholarship to fund her research.
During her time at uOttawa, Sara was particularly involved on campus where she was a member of the Muslim and Environmental Science student associations and part of the Action Against Hunger community. She encourages students to seek out opportunities and to learn as much as they can, both inside and outside the classroom.