A Comparison of Arctic Ocean Sea Ice Export Between Nares Strait and the Canadian Arctic Archipelago

Nares Strait and the channels of the Canadian Arctic Archipelago (CAA) act as conduits for sea ice export from the Arctic Ocean but have never been directly compared. Here, we perform such a comparison for both the sea ice area and volume fluxes from October 2016 to December 2021. Nares Strait provided the largest average seasonal (October through September) ice area flux of 95 +/- 8 x 103 km(2) followed by the CAA regions of the Queen Elizabeth Islands (QEI) at 41 +/- 7 x 10(3) km(2) and M'Clure Strait at 2 +/- 8 x 10 3 km(2) with corresponding ice volume fluxes of 177 +/- 15 km 3, 59 +/- 10 km(3), and 8 +/- 8 km(3), respectively. Larger Arctic Ocean ice export at Nares Strait was associated with a shorter ice arch duration (237 days) compared to M'Clure Strait (163 days) and QEI (65 days). Seasonal Arctic Ocean ice export was dominated by Nares Strait in 2017-2019 and 2021 but was remarkably exceeded by the QEI in 2020. Large-scale atmospheric circulation patterns were found to influence the ice area flux in the absence of ice arches but no occurrence of coherent Arctic Ocean ice export events coinciding across all gates were observed. Average net seasonal Arctic Ocean ice area and volume export were 138 x 10(3) km(2) and 245 km(3), which represent similar to 16% of the area and similar to 25% of the volume of sea ice export from Fram Strait. Divergent Arctic Ocean export ice trajectories are apparent for Nares Strait and the QEI when compared to Fram Strait. Plain Language Summary Sea ice is transported out of the Arctic Ocean via Nares Strait and the channels of the Canadian Arctic Archipelago (CAA) but these export passageways have never been directly compared. Here, we perform such a comparison for both the sea ice area and volume fluxes from October 2016 to December 2021. Nares Strait provided the largest average seasonal fluxes followed by the CAA regions of the Queen Elizabeth Islands (QEI) and M'Clure Strait. Larger Arctic Ocean ice export at Nares Strait was associated less frequent ice arch formation that halts ice export compared to M'Clure Strait and QEI. No occurrence of a large Arctic Ocean ice export event coinciding across all regions was observed. Arctic Ocean ice export was dominated by Nares Strait in 2017-2019 and 2021 but was remarkably exceeded by the QEI in 2020. Under continued warming, Arctic Ocean ice export from Nares Strait and the QEI are expected to increase.