Submesoscale Dynamics near a Seamount. Part II: The Partition of Energy between Internal Waves and Geostrophy

Abstract

Using velocity and temperature profile surveys collected beside a seamount, the dependence of the energy ratio PE/KE on the aspect ratio (NkH/fkz)2 is compared with theoretical relations for linear internal waves and geostrophy. The kinetic and potential energies are partitioned between these two types of motion. The vertical wavelengths of 50?400 m and horizontal wavelengths of 1?20 km spanned by the measurements have traditionally been associated with internal waves. Most of the energy is in the largest vertical and horizontal scales. This larger-scale energy is split between internal waves and geostrophy in one survey and is all geostrophic in the other. Both internal waves and geostrophy contribute to smaller scales.