57A081
Large sea-ice outflow into the Nares Strait in 2007
Ron Kwok, Leif Toudal Pedersen, Preben Gudmandsen
Corresponding author: Ron Kwok –
ronald.kwok@jpl.nasa.gov
Sea-ice flux through the Nares Strait is most active
during the fall and early winter, ceases in mid- to late-winter after the
formation of ice arches along the strait, and recommences after break-up in
summer. In 2007, ice arches failed to form. This resulted in the highest outflow
of Arctic sea ice in the 13 year record between 1997 and 2009. The 2007 area and
volume outflows of 87 × 103
km2 and 254
km3 are more than twice the 13 year
means. This contributes to the recent loss of the thick multi-year Arctic sea
ice and represents ~10% of our estimates of the mean ice export at Fram Strait.
Clearly, the ice arches control Arctic sea-ice outflow. The duration of
unobstructed flow explains more than 82% of the variance in the annual area
flux. In our record, seasonal stoppages are always associated with the formation
of an arch near the same location in southern Kane Basin. Additionally, close to
half the time another ice arch forms just north of Robeson Channel prior to the
formation of the Kane Basin arch. Here, we examine the ice export with
satellite-derived thickness data and the timing of the formation of these ice
arches.
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