TABLE 3 

 p VALUES FOR VARIOUS STABILITY INDEX GROUPS 



Stability index At (°F) 



P 



Stability index At(°F) 



p 



2° (0°-4°) 

 5° (U°-6°) 

 7° (6°-8°) 

 9° (8°-10°) 



108.2x10 3 

 42.8xl0 3 

 28.7xio 3 

 22.2xl0 3 



11° (10°-12°) 

 13° (12°-l4°) 

 150 (i4°-l6°) 

 17° (16°-18°) 



17.2xl0 3 



l3.3xio 3 



10.3xlo3 



8.0xl0 3 



Computed p values are assumed to correspond closely to the representa- 

 tive values of At for each At interval. The normal 17 curves in Figures 15 

 through 22 are plotted with these values of p. The normal 17 curve for the 

 At interval of 0° to h° is a very open parabola. As stability indexes 

 increase, 77 curves aline downward in a rather regular way so that increase 



of the stability index by one degree Fahrenheit results in the ratio -= — ' 



p n 

 where n is the stability index in whole degrees. For stability 

 indexes between 1° and 7° F this ratio increases by a constant amount for 

 each degree Fahrenheit as follows: 



= 0.6 + 0.04, ^3 = 0.6 + 2(0.04)... ^+1 = 0.6 + n(0.0U) 



Pn 



Pi 



P 2 



For At of 1° F, p is 179.4xlo3. The equation for computation of sub- 

 sequent 77 curves is 



V* .=r2p Al (0.6 + 0.04) (k-k' _)!' 2 (Q s 



For At equal to 7° and more, the ratio 

 0.88. Equation (9) then becomes 



Pn+1 



becomes constant and is 



% t =[i.76p At (k-k' n ..)1 



1/2 



(10) 



The value of p, 108.2xlo3, obtained from the distribution of points and 

 applied to compute the normal 77 curve for the At interval of 0° to k F 

 does not correspond exactly to the value obtained from the law of p ratios 

 for At of 2°. It corresponds to a value which is slightly higher, approxi- 

 mately 2.13° F. This is quite understandable, because samples close to 

 At of 0° are neglected in computing k values, and the representative mean 

 value for this interval is slightly greater than the median. 



Convergence and Divergence 



If the wind field remains stationary for a period of time or is propa- 

 gating slowly enough to produce fully developed or nearly fully developed 

 sea, the pure wind current associated with the wind field should create 

 areas of convergence and divergence. However, the problem is quite complex 



30 



