Difference between Onshore wind farms and offshore windfarms

I’m new to this forum. I’m a PhD student from NTU, Singapore. My area of research is in modellling hybrid wake modelling in an windfarm. Initially for understanding BEM method and CFD analysis and for validation with experimental results, I used datas from NREL Phase VI turbine. Now I’m trying to work on wake analysis. What is the aerodynamic difference between onshore and offshore windfarms. My Professor told me NREL Phase VI turbine is tested in wind tunnels. Now we have to work on wind farms especially in offshore windfarms. So far from rotor aerodynamics, I guess there is no difference between offshore or Onshore turbines. But I’m not much aware of difference in wake aerodynamics. So can pls give me suggestion, regarding my further research and also concern in difference between onshore and offshore windfarms

The major difference between the onshore and offshore from a fluid mechanics perspective is the roughness height.
Due to vegetation and uneven surface, onshore roughness height is about 100 times larger than that of offshore.
A typical roughness height for an offshore condition is z = 0.0001m and depends on the wave height.
Please refer to Atmospheric Science book by Stull which provides more details.