Pathways for the Export of Arctic Change into the North Atlantic


OCCI/Arctic Research Initiative
2007 Funded Project


Diminishing sea-ice cover, increased glacial melt, altered river discharge are only some of the changes that have occurred in the Arctic region over the last few decades, and that are already having an impact on the local ecosystems and societies.  As these changes spread into the North Atlantic, a sensitive spot for our climate system, we fear (and models predict) that these changes may have a considerable impact on the global scale.  One major pathway for the propagation of changes, occurring in the Arctic region, is via the swift ocean currents that emerge from Davis and Hudson Straits and plunge into the Labrador Sea.  While these were originally considered two distinct routes, recent observations have revealed that this may not be the case.  It seems, indeed, that a considerable fraction of the Davis Strait outflow turns into Hudson Strait instead of flowing directly into the North Atlantic.  This detour may not only add a considerable delay to the arrival of change in the North Atlantic, but it may also modify the anomalies in a nontrivial way.

Here we propose to measure what fraction of the Davis Strait outflow detours into Hudson Strait and, subsequently, into the extensive Hudson Bay region, by deploying a moored array in Hudson Strait.  The measurements make use of new mooring technology, developed at WHOI, for making year-long observations under an ice-covered region.  The work will be carried out in collaboration with Canadian colleagues from Quebec who will supply the icebreaker, the ship time and two supporting moorings to the state-of-the-art WHOI mooring.  These measurements will occur simultaneously to observations being carried out in Davis Strait and give us an unprecedented, unique understanding of how Arctic change propagates into the North Atlantic.  These observations are crucial to our ability to predict the impact of Arctic change on two different ecosystems: that of the Hudson Bay region and that of the northeastern US/Canadian coasts.  The former is a diverse Arctic ecosystem found in a region that is moving towards an ice-free state faster than the Arctic Ocean itself.  The latter is a highly productive region that supports large fisheries, which has already been shown to be highly sensitive to Arctic change.