Articles | Volume 11, issue 1
https://doi.org/10.5194/os-11-175-2015
https://doi.org/10.5194/os-11-175-2015
Research article
 | 
06 Feb 2015
Research article |  | 06 Feb 2015

A wind-driven nonseasonal barotropic fluctuation of the Canadian inland seas

C. G. Piecuch and R. M. Ponte

Abstract. A wind-driven, spatially coherent mode of nonseasonal, depth-independent variability in the Canadian inland seas (i.e., the collective of Hudson Bay, James Bay, and Foxe Basin) is identified based on Gravity Recovery and Climate Experiment (GRACE) retrievals, a tide-gauge record, and a barotropic model over 2003–2013. This dominant mode of nonseasonal variability is correlated with the North Atlantic Oscillation and is associated with net flows into and out of the Canadian inland seas; the anomalous inflows and outflows, which are reflected in mean sea level and bottom pressure changes, are driven by wind stress anomalies over Hudson Strait, probably related to wind setup, as well as over the northern North Atlantic Ocean, possibly mediated by various wave mechanisms. The mode is also associated with mass redistribution within the Canadian inland seas, reflecting linear response to local wind stress variations under the combined influences of rotation, gravity, and variable bottom topography. Results exemplify the usefulness of GRACE for studying regional ocean circulation and climate.

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Short summary
A wind-driven, spatially coherent mode of nonseasonal depth-independent variability in the Canadian inland seas is identified based on observational measurements and a numerical model over 2003--2013. This dominant mode of nonseasonal variability is partly related to the North Atlantic Oscillation. The mode is associated with net flows into and out of the Canadian inland seas as well as internal mass redistribution within the Canadian inland seas.