ALBERT

Beschreibung: The objective of this paper is to examine the thermodynamic and dynamic forcing of sea ice within the Hudson Bay System, including Hudson Bay, Hudson Strait, and Foxe Basin. Changes in fall and spring sea ice extents (SIEs) are examined in relation to seasonal surface air temperatures (SATs) and winds, as are changes in freeze-up dates and breakup dates. The proportional leverage of the fall (lag1) and spring SATs and winds on ice is statistically examined per basin. Results show SATs have increased significantly since the mid-1990s and that increases in the fall are higher than the spring period. Fall SATs are highly related to fall SIEs ( R 2 = 0.79-0.82). For every 1 °C increase in SAT, SIE decreases by 14% (% of basin area) within the Hudson Bay System; a 1 °C increase delays freeze-up by 0.7 to 0.9 weeks on average. Spring SIEs and breakup dates are shown to be highly correlated with fall (lag1) and spring SATs, and with U and V component winds. Proportionately, spring and fall SATs combined play a dominant role (70-80%) in SIE, and the remaining leverage is attributed to dynamic forcing (winds). The relative leverage of fall (lag1) SATs and surface winds are shown to be significant and vary by basin. The open water season has on average increased by 3.1 (±0.6) weeks in Hudson Bay, 4.9 (±0.8) weeks in Hudson Strait, and 3.5 (±0.9) weeks in Foxe Basin. Content Type Journal Article Pages 66-83 DOI 10.1657/1938-4246-46.1.66 Authors Klaus P. Hochheim, Centre for Earth Observation Science (CEOS), Clayton H. Riddell Faculty of Environment, Earth, and Resources, University of Manitoba, Wallace Building, 125 Dysart Road, Winnipeg, Manitoba, R3T 2N2, Canada David G. Barber, Centre for Earth Observation Science (CEOS), Clayton H. Riddell Faculty of Environment, Earth, and Resources, University of Manitoba, Wallace Building, 125 Dysart Road, Winnipeg, Manitoba, R3T 2N2, Canada Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 46 Journal Issue Volume 46, Number 1 / February 2014