Nares Strait Ice Flux

Six years (1996-2002) of Arctic Ocean ice flux through Nares Strait are estimated using ice motion from RADARSAT. Across an ~30 km gate at the entrance to Robeson Channel, the average annual (Sept-Aug) ice area flux is 33x103 km2 and ranges from 16x103 km2 in 2000 to 48x103 km2 in 1999. Uncertainties in the ice displacements from high-resolution synthetic aperture radar imagery, at ~100-300 m, are small. Assuming sea ice that is 3 m thick, the average volume flux amounts to ~100 km3 (~3 mSv); this is ~5% of the mean annual Fram Strait ice flux (1978-2003). 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 the late spring. The multiyear ice coverage of the area poleward of the gate is high (>80%). South of the gate, the multiyear ice coverage is highly variable and is reduced as individual floes, small enough to fit through the channel, are broken off the Arctic pack. After the formation of an ice arch in winter, the channel may be filled with multiyear or seasonal ice. The details of the ice flux estimates are presented.