“…Approximate methods have been developed and improved, including the method of averaging, the boundary layer method, the matched asymptotic expansion method, and the multiple scales method (Dawes and Proctor, 2008;Graef and Kong, 2008;Hovhannisyan and Vulanovic, 2008;Ramos, 2009). Using the perturbation method, Mo et al studied some of nolinear perturbation problems (Mo et al, 2004;2007a;2007b;Mo and Wang, 2007;Mo and Lin, 2008a;2008b;2008c;Mo, 2009a;2009b;2009c). In this paper, we discuss a model of the thermally and wind-driven ocean circulation and obtain an approximate solution of the model by using the homotopic mapping perturbation method.…”