A river‐coastal sea ice interaction model: Mackenzie River Delta

Abstract

It has been observed that arctic coastal regions which receive river discharge show significant ice regression in advance of other coastal areas without this source of sensible heat. This phenomena has been particularly apparent on satellite imagery. The work reported here attempts (1) to quantify and assess the influence of springtime river discharge on the removal of nearshore ice and (2) to demonstrate the utility of satellite imagery as a source of data to “drive” a model assessing the influence of springtime river discharge on the removal of nearshore ice. Central to this work is a sequence of advanced very high resolution radiometer images of the Mackenzie Delta region, Northwest Territories, Canada. These images constitute a database establishing the temporal sequence of observable breakup events from which a thermodynamic model for the ice decay can be parameterized. The emphases of this model are the influence of the riverine sensible heat on the melting of sea ice and the ability of satellite imagery to monitor this process. For simplicity, climatological values rather than meteorological values for atmospheric and solar influences have been used. The results suggest that the river discharge supplies a significant amount of sensible heat to the base of the nearshore ice, accounting for nearly half of the energy required to melt the ice cover. As a result, the coastal ice is removed 7–14 days in advance of areas without significant river discharge.