Numerical Simulation of Internal Tides and Comparison to Observation

  • Author / Creator
    Li, Kehan
  • As internal tides propagate in the ocean, they carry and dissipate energy over hundreds and even thousands of kilometers. We perform fully nonlinear simulations to examine the evolution of horizontally propagating, vertical mode-1 internal tides in non-uniformly stratified fluids, as it depends on wave amplitude, ocean depth, Coriolis forces, and the spanwise extent of the waves. The background stratification is set up according to ocean measurements southwest of Hawaii and in the South China Sea. Two-dimensional (2D) simulations on the beta-plane are based on the internal tides originating near the Hawaiian Ridge and propagating southwest towards the equator. The results are compared to the ocean measurements from the EXperiment on Internal Tidal Scattering (EXITS). Another series of 2D simulations on the f-plane is set up based on the internal tides propagating westward in the South China Sea and are compared to the observations. The simulations in both research domains align qualitatively and somewhat quantitatively with the observations. A three-dimensional (3D) model simulating spanwise-localized waves is utilized to characterize the evolution of internal tides in the streamwise and spanwise direction. The spanwise evolution of the 3D waves is examined in terms of the lateral spreading, radius of curvature, and sea surface signature. The evolution of sea surface signature is compared favourably to a satellite image in the South China Sea. The 3D model can thus be used to reversely deduce the initial conditions of internal tides.

  • Subjects / Keywords
  • Graduation date
    Fall 2023
  • Type of Item
  • Degree
    Master of Science
  • DOI
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.