Abstract
A weakly nonlinear correction for the 2-dimensional linear formula of mountain drag is considered. The mountain profile is assumed to be symmetric, and the nondimensional mountain height is assumed to be small and of 0 (ε). To the leading order, the mountain drag is proportional to ε2, and is given by the linear formula. The next order term is proportional to ε4. For a particular mountain profile, the 0 (ε4) correction term is calculated. This correction term is shown to be positive. As a result, at least to 0 (ε4), the nonlinearity can be said to enhance the mountain drag.
