Lateral stirring by internal waves
Abstract
Abstract: Lateral stirring by internal waves Our analysis of the 2011 LatMix observations and numerical simulations of disper- sion in broadband internal wave elds suggest that the ubiquitous O(1) m2/s lateral di usivity may be explained entirely by Stokes drift from linear internal waves. We believe that we have identi ed the key physical ingredients necessary to reproduce observed and model Stokes drifts. However, to put this mechanism on rmer ground, we need to explore whether this level of di usivity can be understood from rst physi- cal principles and to discern whether the di usivity observed in nonlinear simulations is due to the same physical mechanism. The rst task will be to extend our preliminary theoretical results by computing the next order solution of the Lagrangian kinetic energy spectrum. This prediction provides an estimate for di usivity due to Stokes drift and will be validated against a suite of linear analytical model runs, but also compared against nonlinear Boussinesq simulations to determine the regimes under which this mechanism is expected to dominate. In order to determine if Stokes drift is controlling the di usivity at various energies in the nonlinear ow, we will extract the linear internal wave component of the ow, thereby allowing us to determine the underlying mechanisms controlling the ow. The net result of this work will be a prediction of the di usivity for drifters and dye from linear internal waves given an arbitrary strati cation pro le and energy level, and an improved understanding of the conditions controlling submesoscale lateral di usivity in environments dominated by internal waves. 1
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 12, 2016
- Source ID
- N000141512465
Entities
People
- Jeffrey Early
Organizations
- Northwest Research Associates
- Office of Naval Research
- United States Navy