J. Dudhia, MMM/NCAR

Long-term tower data over the North Sea has been used to develop a modified roughness length for shallow water (Jimenez and Dudhia, 2018, J. Appl. Meteor. and Clim.). This modification reduces a high wind bias over shallow water and has been generalized following previous theory from the 30 meters tested to other depths less than 100 meters at which it converges to a deep water function.