Advances in Meteorology

Research Article

Methods to Estimate Surface Roughness Length for Offshore Wind Energy

Table 2

Mean and standard deviation of wind speed (by season and overall) measured from buoy 44020 during 2003–2007 at 5 m, the IMPOWR campaign during 2013–2014 at 12 m, and the CW tower during 2003–2007 at three different heights. All heights are in meters above mean sea level.


	Buoy	IMPOWR	CW Historical
	5 m	12 m	20 m	41 m	60 m

ALL
Mean (m/s)	6.52	7.39	7.84	8.43	8.82
Standard deviation (m/s)	3.58	3.25	3.66	3.92	4.12
Count	202,830	19,633	214,458	214,458	214,458

DJF
Mean (m/s)	8.73	7.95	9.01	8.20	8.58
Standard deviation (m/s)	3.76	3.35	4.09	4.30	4.45
Count	48,972	3,353	50,592	50,592	50,592

MAM
Mean (m/s)	6.46	7.67	7.79	8.51	9.06
Standard deviation (m/s)	3.35	3.33	3.60	3.91	4.17
Count	47,701	9,677	50,974	50,974	50,974

JJA
Mean (m/s)	4.40	6.51	6.46	6.95	7.48
Standard deviation (m/s)	2.16	2.25	2.50	2.80	3.10
Count	52,331	2,399	54,567	54,567	54,567

SON
Mean (m/s)	6.48	7.97	7.81	8.28	8.65
Standard deviation (m/s)	3.48	3.21	3.80	4.08	4.22
Count	53,826	4,203	58,325	58,325	58,325