The effects of a rough topography are investigated in a primitive equation, eddy-resolving circulation model of an idealized ocean basin. The topography is chosen as a random field with an isotropic spectrum, specified according to observed abyssal hill topographies. The interactions of the deep current fluctuations with the synoptic-scale irregularities of the ocean floor enhance the baroclinicity of the eddy field; whereas a strong tendency toward barotropization is revealed in a flat-bottom solution, the topographic influence leads to a substantial decrease of eddy kinetic energy below the thermocline and a much more depth-dependent structure, especially in areas of weaker flow intensity. Energy budgets indicate that the adjustment after the introduction of the bottom roughness is dominated by a strong reduction of energy in the external mode. While eddy energy in the thermocline is not significantly altered in the new equilibrium state, energy in the deeper layers is scrambled into smaller, t... Abstract The effects of a rough topography are investigated in a primitive equation, eddy-resolving circulation model of an idealized ocean basin. The topography is chosen as a random field with an isotropic spectrum, specified according to observed abyssal hill topographies. The interactions of the deep current fluctuations with the synoptic-scale irregularities of the ocean floor enhance the baroclinicity of the eddy field; whereas a strong tendency toward barotropization is revealed in a flat-bottom solution, the topographic influence leads to a substantial decrease of eddy kinetic energy below the thermocline and a much more depth-dependent structure, especially in areas of weaker flow intensity. Energy budgets indicate that the adjustment after the introduction of the bottom roughness is dominated by a strong reduction of energy in the external mode. While eddy energy in the thermocline is not significantly altered in the new equilibrium state, energy in the deeper layers is scrambled into smaller, t...