ABSTRACT 



These charts, based on ship injection temperature data, show the 

 monthly maximum, minimum, and mean sea surface temperatures for 

 the Indian Ocean. The data are numerous in all but the southernmost 

 portion of the area, and the addition of new data probably will not greatly 

 change the analysis. 



Upwelling along the coasts of the continents is evident on the charts. 

 Of particular interest is a little- studied region off the coast of the Somali 

 Republic, where during the southwest monsoon, the mean temperature 

 in one 1° quadrangle drops to 4°F. less than the mean temperature in 

 the surrounding 1° quadrangles. The maximum and minimum sea sur- 

 face charts show temperature variations which are sometimes masked by 

 the averaging of the temperatures on the mean charts, as in the Antarc- 

 tic Convergence, which is best shown on the maximum charts. 



The graphs of monthly variability of temperature in selected locations 

 show that surface temperature values in the Indian Ocean north of the 

 Equator have two maximum periods during the year, as compared to one 

 maximum per year in the Pacific and Atlantic Oceans. 



Because of the large quantity of data involved, these charts, in general, 

 are more definitive than charts of other parameters such as salinity, except 

 where the analysis were based on fewer than 25 observations per 1° quad- 

 rangle or in regions where the 1° quadrangle averaging disguises more 

 complex thermal structure. 



PAUL E. LA VIOLETTE 



and 



CURTIS MASON 



Physical Properties Section 



Oceanographic Analysis Division 



Marine Sciences Department 



