of HOTEL was used as the accepted factor » The same uncertainty existed 

 in choice of phase angle values. The phase angle for the second harmonic 

 at DELTA is not very realistic and was apparently distorted by frequent 

 mass advection. The phase angle for the second harmonic at ERAVO does 

 not provide clear indication of variability of this angle with latitudej 

 therefore the phase angle of HOTEL was used as the accepted factor » The 

 assumption that the angle °'2.400 varies little with latitude is some- 

 what corroborated by the relatively small variation of a 1,400 with lati- 

 tude. 



Substitution of the accepted parameters in equation {k) yields 

 ^400 = 0g g-5.51 cos (^ + A6'"'-^'^''"'^cosLt + 153 sin <^)+ ., 



Equation (lO) is for the DELTA-HOTEL type of oceanographic conditions 

 and applies mainly in areas with latitudinal mass transport. 



Equations (9"^ and (lO) can be applied in all cases where oceanographic 

 conditions may be generalized and approximated to one of the two types of 

 conditions represented by the equations. However, two special areas con- 

 sidered in this study do not approximate the conditions for equations (9) 

 and (10). One (area G, figure 1) lies in a subtropical convergence zone, 

 and the other (area H, figure 1) lies in an upwelling region, ^5o^e such 

 special areas could probably be located; however, none have a similar degree 

 of independence and distinctness. 



Special conditions in the subtropical convergence zone are created 

 mainly by the relative shallowness of the seasonal thermocline in winter. 

 Wot only is it shallow (about 300 to 500 feet), but also it has a rather 

 large gradient. The thermocline is more permanent than seasonal and os- 

 cillates about the ^WO-foot level. The phase angle at ij-00 feet is turned 

 by about l80°. The maximum temperature at ij-00 feet occurs in spring rath- 

 er than in fall or early winter as expected (figure 6). During summer, 

 this water is apparently cooled more from below by some mechanism (prolaably 

 by admixture from deeper strata) than it is heated from above. Temperature 

 of the mixed layer in winter does not fall below the temperature at UOO feet 

 in summer. As the mixed layer thickness increases and the interface increases 

 in depth, the temperature at i<-00 feet is raised by the higher temperature of 

 the mixed layer. 



Area G does not cover the entire subtropical convergence but is con- 

 sidered to represent a typical portion of it. Data were not sufficient 

 for computing parameters along two latitudes; however, since the cosine 

 function was found to apply for the mean annual temperature parameter X in 

 the rest of the ocean, it was also assvuned to be applicable in this area. 

 The same assumption was made for the sine function in the exponent. Phase 

 angles were held constant throughout the area. Possible latitudinal vari- 

 ations are considered to be small. Setting computed factors from Fourier 

 expansion in eg^uation (h) and extending to four harmonics results in: 



Ik 



