Multimodel Arctic Ocean “climate response function” experiments are analyzed in order to explore the effects of anomalous wind forcing over the Greenland Sea (GS) on poleward ocean heat transport, Atlantic Water (AW) pathways, and the extent of Arctic sea ice. Particular emphasis is placed on the sensitivity of the AW circulation to anomalously strong or weak GS winds in relation to natural variability, the latter manifested as part of the North Atlantic Oscillation. We find that anomalously strong (weak) GS wind forcing, comparable in strength to a strong positive (negative) North Atlantic Oscillation index, results in an intensification (weakening) of the poleward AW flow, extending from south of the North Atlantic Subpolar Gyre, through the Nordic Seas, and all the way into the Canadian Basin. Reconstructions made utilizing the calculated climate response functions explain ∼50% of the simulated AW flow variance; this is the proportion of variability that can be explained by GS wind forcing. In the Barents and Kara Seas, there is a clear relationship between the wind-driven anomalous AW inflow and the sea ice extent. Most of the anomalous AW heat is lost to the atmosphere, and loss of sea ice in the Barents Sea results in even more heat loss to the atmosphere, and thus effective ocean cooling. Release of passive tracers in a subset of the suite of models reveals differences in circulation patterns and shows that the flow of AW in the Arctic Ocean is highly dependent on the wind stress in the Nordic Seas.@en

The stratification in the water column above the Labrador Sea Water layer in the central Labrador Sea is set by the properties of its boundary currents. The top part is fresh and (in winter) cold water of Arctic origin, while the subsurface layer contains warm and saline water of subtropical Atlantic origin. The buoyancy stored in these layers is determined by their T/S properties and is a primary factor in determining the occurrence of deep water formation and the properties of the water mass formed. The characteristics of both source regions of these boundary currents are, however, changing rapidly and are projected to change further in the coming decades. Using a 1D mixed layer model and analysis of three recent year-round data sets of hydrographic observations, we analyze how anomalies in the boundary current characteristics have impacted the mixed layer depth and properties in the recent past, and make projections for how changes in the boundary current properties are likely to affect them in the future.@en

The Canadian Arctic Archipelago is one of the two major oceanic gateways between the Arctic and the Atlantic Ocean. It has been estimated that the flow through this region currently accounts for about half of the freshwater transport between these two oceanic basins, its importance potentially increasing with increased melting of sea ice. However, factors such as its complex morphology, harsh meteorological conditions, the remote location and an almost continuous presence of sea ice form a hindrance to understanding the dynamics that force the flow through this region. In contrast to previous efforts which all used realistic model configurations, the approach in this study is one of a simple straight channel representing Nares Strait in a 3D primitive equation model. This enables us to disentangle and quantify the effects of barotropic forcing, baroclinic forcing, wind stress, ice cover and tides acting to drive or reduce the throughflow or alter its cross-strait structure.@en