Title

The Use of Ocean Tomographic Observations in Numeric Simulation of Mesoscale Oceanic Circulation in the Northern Gulf of Mexico

Date of Award

2005

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Marine Science

First Advisor

Jerald. W. Caruthers

Advisor Department

Marine Science

Abstract

Warm-core mesoscale eddies have a considerable effect on the coastal oceanic environment and climate as they bring large-scale, contrasting properties into the local weather systems and near-shore waters. Consideration of oceanic mesoscale circulation is crucial for weather forecasting and for many offshore activities such as oil recovery, mineral mining and fisheries. Although the sea-surface altimetry provides near-real-time data for ocean models, still, there are no sustained observations of the vertical structure of the ocean. The ocean's interior can be observed by means of ocean acoustic tomography and then assimilated into circulation model. This work provides computational support for a future vertical two-dimensional tomographic slice consisting of a single acoustic source at depth of thermocline and a vertical linear array of acoustic receivers. Potential tomographic observations are the arrival times and depths of acoustic rays traveling through the stratified ocean. A Primitive Ray Tracing (PRT) model has been developed to compute possible arrivals for given oceanic states and help in solving the inverse tomographic problem by means of both statistical and adjoint algorithms. A series of so-called twin experiments have been used in a sensitivity analysis of the regional eddy-resolving ocean model forecast to data assimilation along the vertical tomographic slice. As an outcome, the best computational and observational configuration is proposed in order to optimize the effect of tomographic observations.