Methods to Estimate Surface Roughness Length for Offshore Wind Energy

Table 3

Information used to calculate with each of the three methods and associated equation(s) to calculate the vertical wind speed profile .

Method to estimate	Information available to calculate				Equation to calculate
	One 3D sonic anemometer			Sonic/cup at 3 levels	Log-law (Equation (4))	Simplified log-law (Equation (6))
	Stability		Wind speed	Wind speed
Analytical
Charnock
Statistical