Mean Kinetic Energy and Its Projected Changes Dominate Over Eddy Kinetic Energy in the Arctic Ocean

Abstract

As sea ice retreats in a warming climate, the Arctic Ocean is becoming more energetic; yet little is known about this additional energy's distribution in the water column. We use a high-resolution (3–4 km) pan-Arctic ocean-sea ice model forced by present day and future scenarios to examine changes in mean kinetic energy (MKE) and eddy kinetic energy (EKE). Our study suggests that both the mean and eddy fields are becoming more energetic under anthropogenic forcing but changes in the mean circulation dominate the increase, concurrent with a spin-up of the large-scale circulation, concentrated in the top 200 m and along boundaries. The increase in EKE is strongest in the upper 50 m and is linked to enhanced baroclinic instability within the mean boundary currents. A better grasp of the distribution of this energy surplus helps to understand projected changes to stratification, mixing, and circulation in a future Arctic Ocean.