Longitudinal Variation 



The observations used to examine the longitudinal variation 

 were also obtained from Punched Card Deck 116. 



From this deck the sea-surface temperatures taken along a 

 given latitude, ±0.2° of latitude, were selected. Latitude strips, 

 at 3-degree intervals, were selected starting at 30 N. The data 

 for four of these strips— 30°, 36°, 42°, and 48°N— for March and 

 September 1956 and 1957 are plotted on figure 3. 



The data suggest that a third-degree polynomial can be used 

 as a model where 



T'.a^-.agG.a^oG^^a^^G^ (3) 



and G is the longitude. 



Equation (3) was fitted to the above sets of data. The fol- 

 lowing statistics for the data shown on figure 3 were obtained: 



28 



