Instability and flow over topography

摘要: Abstract The stability of quasi-geostrophic β-plane flow over topography is examined. approach to first calculate the stationary, asymmetric response a uniform zonal current flowing topography, and then properties total, zonally asymmetric, field. Under many circumstances this unstable, barotropically or baroclinically particularly if large amplitude. This demonstrated using long-wave approximation, which examines with respect perturbations meridional scale. So-called form-drag instability ensues. may be thought as special, nonlocal, form isosceles triad interaction involving interacting another “free” mode topographic For consisting single Fourier mode, arises only eastward exceeds that required for resonance. However, in general other triads exist th...