Variability of Nares Strait ice flux

Abstract

Six years (1996–2002) of Arctic Ocean ice flux into the Nares Strait are estimated using RADARSAT ice motion. This represents a first consistent multi‐year record of Nares Strait outflow for examination of seasonal and interannual variability. Across an ∼30 km gate at the entrance to Robeson Channel, the average annual (Sept–Aug) ice area flux is 33 × 10 3 km 2 and ranges from 16 × 10 3 km 2 in 2000 to 48 × 10 3 km 2 in 1999. Uncertainties in the 3‐day ice displacements and ice flux are small. Assuming 4 m thick ice, the average volume flux amounts to ∼130 km 3 (∼4 mSv); this is ∼7% of the mean annual Fram Strait ice flux. Seasonally, ice flux is most active after July, ceases after the formation of an ice arch in mid‐ to late‐winter, and re‐commences after breakup in summer. The multiyear (MY) ice coverage of the area poleward of the gate is high (>80%). South of the gate, the MY ice coverage is highly variable and the strait may be filled with multiyear or seasonal ice. Our estimates are placed in the context of others and uncertainties in the other components of Canadian Archipelago ice flux and are discussed.