In this formulation of the Rossby number, we use radius of curvature as the length scale, as this is the parameter that determines the centrifugal force. A large value of the Rossby number means that the centrifugal force dominates; values of \(Ro_r\) below one describe situations in which the Coriolis force is larger than the centrifugal one. In theory, the Coriolis force would suppress the development of highly sinuous channel bends if it counteracted the centrifugal force, which is ultimately responsible for the instability leading to sinuosity development in submarine channels.
From a quick inspection of Eq. 3, it is clear that the Rossby number will tend to be smaller at higher latitudes, low flow velocities, and low curvature channel bends. In addition, taking into account that the angular rotation speed of the Earth is a relatively small number (7.29e- 05 radians/s) and that flow velocities of turbidity currents are unlikely to exceed ~20 m/s, the radius of curvature must be on the order of ~10 km in order to decrease the Rossby number enough so that the Coriolis force really matters.