Why the Northwest Passage and the CAA?

Cynthia Garcia Student Posts Leave a Comment

I am writing from the RVIB Oden – a Swedish research vessel managed by the Swedish Polar Secretariat. It is currently carrying a fleet of scientists, students, and a film crew on a voyage into the Arctic, specifically along the Northwest Passage, including northern portions of Baffin Bay and waterways within the Canadian Arctic Archipelago (CAA).

You are probably asking, why the Northwest Passage and the CAA? We have a number of questions that we will attempt to answer during this cruise. One of them deals with understanding how the waters flow in the region. A significant feature of the CAA are the major flow pathways that act as conduits for the Arctic ocean freshwater to the warm, salt(ier) waters of North Atlantic. Sources of freshwater in this region can come from melt from sea ice, land ice, and meteoric water sources. Freshwater coming from the north (mostly coming from melt from areas that are permanently covered by sea ice), and from the northwest (potentially from freshwater released by the Beaufort Gyre, which are mostly from river run-off). Past observations suggest that the Beaufort Gyre – a clockwise, wind-driven, ocean circulation, released some of its freshwater, following years of ‘spin-up’ and freshwater accumulation. On the other side of this region, some scientists have also observed the intrusion of warm North Atlantic waters. In a way, the dynamics of the flow and mixing in the CAA is complicated because you have a number of major sources and opposing forces. Whether we will observe the same freshwater release, or the hypothesized ‘atlantification’ of the CAA, we are not sure. Either way, with the use of a suite of equipment, we hope to understand the mixing patterns in this region, and whether we are experiencing a new regime of freshwater release from the Arctic.

While changing sea ice, and larger atmospheric patterns and circulation are responsible for the dramatic changes in the region, we are also interested in investigating the regional freshwater budget. In other words, where is the water coming from? And how much are these waters contributing to the CAA freshwater fluxes? Through my research at the University of Illinois at Chicago, and through collaborations with other science teams in this expedition, I am hoping to provide insights into the relative contributions of sea ice and meteoric exports in this region through the use of complementary salinity, nutrients, and O-18 measurements.

You are probably asking again, why should I care about the freshwater dynamics and budget in the Arctic and the CAA? Well, many scientists have hypothesized that a huge influx of freshwater into the wider global ocean could slow down or significantly suppress the global ocean circulation. This could potentially trigger a temporary cooling effect, drastic precipitation changes, and local sea level rise, among other impacts. This is a great example of our saying that “what happens in the Arctic, doesn’t stay in the Arctic”. In addition to this, quantifying the freshwater budget in this poorly studied region can serve as a benchmark in understanding whether the hydrologic cycle is accelerating, and how ocean dynamics is evolving in the face of climate change.

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