Ocean circulation, sea ice, and productivity simulated in Jones Sound, Canadian Arctic Archipelago, between 2003–2016

Abstract. Jones Sound is one of three critical waterways that regulate liquid exchange between the Arctic and northern Atlantic Oceans within the Canadian Arctic Archipelago. However, to date, no high-resolution ocean circulation model exists to study the recent evolution of Jones Sound, meaning that our understanding of circulation within the sound is based either on temporally and spatially sparse oceanographic observations or on extrapolating conditions within Baffin Bay, which has a more dense observational record. To address this, we developed a high-resolution (1/120°, 0.9 km) Jones Sound configuration of the Massachusetts Institute of Technology general circulation model and performed coupled ocean-sea ice-biological productivity simulations between 2003–2016 to investigate recent changes within this waterway. We find that circulation through Lady Ann Strait, Fram Sound, and Glacier Strait comprise 75 %, 14 %, and 11 % of the volumetric transport into and out of Jones Sound, with tidal flushing enhancing the magnitude and temporal variability of volumetric transport through all three waterways. Warming Atlantic Water within western Baffin Bay flows into Jones Sound through Lady Ann Strait, becomes well-mixed, and circulates counter-clockwise, encroaching on the terminus of most tidewater glaciers that line the eastern periphery of the sound. Furthermore, we find that sustained atmospheric and oceanic warming drive an 11 % reduction in the summertime sea ice extent, decreased wintertime sea ice thickness, and delayed onset of sea ice refreeze in the fall (thus lengthening the amount of time in which Jones Sound is ice free). Tidal flushing through Cardigan Strait is critical in triggering meltback of sea ice across northern Jones Sound. Lastly, this decline in sea ice increases light availability and coupled with warming of the subsurface waters in Jones Sound, facilitates enhanced primary productivity at ocean levels down to ~21 meters depth. While we note that the modeled warming signal in Baffin Bay is overestimated compared to observations, the results presented here improve our general understanding of how this critical waterway might change under continued polar amplified global warming and underscores the need for sustained oceanographic observations in this region.