title: On a Wind-Driven, Double-Gyre, Quasi-Geostrophic Ocean Model: Numerical Simulations and Structuraln Analysis Authors: Jie Shen, T. Tachim Medjo and S. Wang Status: Submitted to J. Comput. Phys. July 1998. Abstract: The main objective of this article is to study the double-gyre phenomena of the mid-latitude Atlantic ocean from the numerical and structural analysis points of view. A wind-driven, double-gyre, mid-latitude, quasi-geostrophic ocean model is adopted. An efficient and accurate spectral-projection method is developed and implemented for this model. A number of numerical simulations are carried out and their structural stability and structural transitions/bifurcations are investigated using a new dynamical systems theory of two-dimensional incompressible flows.