This correction is 



where 



("4 



b a 



— 1 u°(x ^ z) 



hain j ; 



-1 



in which 



h = height of the hill 



a = 1.0 



L = factor of island length 



Zq = roughness length 



u° = dimensionless quantity representing the perturbation of 

 the upwind velocity due to the presence of the hill 



z = anemometer height above the island 



J, = thickness of the internal boundary layer 



This correction assumes that L is much larger than h and that it is rural 

 terrain. A maximum correction of 0.65 was applied in the direction of the 

 short axis of the island, and a minimum correction of 0.85 was applied in the 

 direction of the long axis of the island. These corrections were made so wind 

 data could be applied directly to wave forecasting curves. 

 Wind summary 



42. The same computer program used to analyze the NWS data was used for 

 the Puffin Island data. Data were available for only the 3-hr averages, so 

 summaries were produced for the 3- and 6-hr winds. Of the 4,800 observations, 

 17 percent were bad. 



43. The distribution of the hourly wind with respect to direction is 

 shown as a wind rose (Figure 20). The wind rose shows the distribution of 

 winds in 16 directional sectors as a percent of all winds. The bars are 

 broken into 10-mph intervals. 



44. The short period of record for the data from Puffin Island anemom- 

 eter makes it difficult to create reliable curves for wind speed and duration 

 versus return period. The best use for this data is for comparison with the 

 NWS data. 



46 



