Measurement instrument 



25. Winds were measured on top of the laboratory building at an eleva- 

 tion of 19.1 m (Figure 2) using a Weather Measure Corporation (Sacramento, CA) 

 Skyvane Model W102P anemometer. Wind speed and direction data were collected 

 on the FRF computer as well as on a strip-chart recorder. The anemometer manu- 

 facturer specifies an accuracy of ±0.45 m/sec below 13 m/sec and 3 percent at 

 speeds above 13 m/sec, with a threshold of 0.9 m/sec. Wind direction accuracy 

 is ±2 deg with a resolution of less than 1 deg. The anemometer was calibrated 

 semiannually at the National Bureau of Standards in Gaithersburg, MD, and is 

 within the manufacturer's specifications. 



Results 



26. Annual and monthly joint probability distributions of wind speed 

 versus direction were computed. Winds speeds were resolved into 3-m/sec in- 

 tervals, while the directions were at 22.5-deg intervals (i.e. 16-point com- 

 pass direction specifications) . These distributions are presented as wind 

 "roses," such that the length of the petal represents the frequency of occur- 

 rence of wind blowing from the specified direction, and the width of the petal 

 is indicative of the speed. Resultant directions and speeds were also deter- 

 mined by vector averaging the data (see Table 2) . Wind statistics are pre- 

 sented in Figures 9 through 11. 



15 



