Table 40. 

 MEAN DIRECTION OF THE WIND BY LAMBERT'S FORMULA. 



E - W+ (NE + SE - NW- SW) cos 45 



tana.= 



N- S + {NE 4- NW- SE - SW) cos 45° 

 Multiples of cos 45°. 



is the angle between the mean wind direction and the meridian, 

 he signs of the numerator {11) and denominator (d) determine the quadrant inwhichalies. 

 When n and d are positive, a lies between N and E : — = NE. 



When n is positive and d negative, a lies between S and E : — = SE. 



When « and d are negative, a lies between S and W : — = SW. 



When n is negative and d positive, a lies between N and W : — = NW. 



T 

 71 



