text: As briefly mentioned in Section: Impact on Models for large-scale Ocean Circulation, the surface currents can be calculated by forcing surface winds into a general circulation model. The case of a model which is also forced by relative wind stress can be visualized in Figure 5. Firstly, the satellite data is used to input the 10m wind velocity into the calculation of the relative wind stress. However, if the parameterization for relative wind stress is used, this will result in a coupled problem. The ocean model requires the relative wind stress  to output the ocean current velocity, which in turn the calculation of  relies on. This coupled system needs to be formulated as an inverse problem.
  Another consequence is that, depending on the parameterization used for the wind stress, a different vector field will be inputted into the ocean model and, consequently, a different value of  will be outputted by the ocean model. Therefore, if a different wind field  is used for the calculations of  and  then it could be that . In other words, there may be a negative bias when calculating the work done on the ocean using the resting ocean approximation. On the global scale, however, the literature has found an over rather than underestimation, as previously mentioned.