Arctic Sea Ice Area Export Through the Fram Strait Estimated From Satellite-Based Data:1988–2012

Abstract

By combing ice motion and concentration fields, we obtain the estimates of ice area flux passing the Fram Strait over a 25-year period (1988–2012). Mean monthly area flux exhibits a prominent cycle with the peak in March $\rm{(78 \times 10}^{3}\,\text{km}^{2}\text{/month)}$ and the trough in August $\rm{(5 \times 10}^{3}\,\text{km}^{2}/\text{month)}$ . Mean net annual ice area flux $\rm{(644.1 \times 10}^{3}\,\text{km}^{2}\,\text{km}^{2}\rm{)}$ is primarily/slightly attributable to winter (October–May)/summer (June–September) outflow of $\rm{598.7\times 10}^{3}\,\text{km}^{2}$ $\rm{(or\; 93.0\%)/ 45.4 \times 10}^{3}\,\text{km}^{2} (\rm{or} 7\%)$ . However, these quantities need to be considered with great prudence since comparisons with preceding studies indicate distinct difference may exist between calculated Fram Strait sea ice outflow based on varied ice motion datasets. In particular, major bias emerged during winter rather than summer. Trends are also affected due to this bias. Despite the clear disparity in magnitude, we found a good agreement with preceding estimates in terms of temporal variability. The linkage between ice area flux via the Fram Strait and various atmospheric circulation indices, such as the Arctic Oscillation (AO), the North Atlantic Oscillation (NAO), a west-east dipole anomaly pattern (DA), as well as a seesaw structure between Beaufort and Barents Sea (BBO), was examined. Results show that atmospheric circulation patterns linked to the DA and BBO possess a relatively stronger influence on Fram Strait ice export over the 25-year period. By contrast, the AO- and NAO-related atmospheric circulation pattern exhibit weaker connections with ice outflow through the strait. In addition, correlation analysis further justify the robust connection with a cross-strait surface level pressure gradient index. Depending on months, it is suggested that a manifold of aforementioned atmospheric indices may jointly or alone impose a significant influence on sea ice export through the Fram Strait.