station 14 (Fig. 21B), the salinity curve sharply decreased between 100 and 

 300 meters, and from the latter depth showed only slight change to the bottom 

 of the cast. At station 17, (Fig. 21C), the patch of high salinity water was 

 encountered at 75 meters, and below the lower margin at 200 meters depth, 

 conditions were relatively uniform to the bottom of the cast. At station 27 

 (Fig. 22B), the most northerly of this section, 35. O&^j, water extended down 

 as far as 900 meters. There was a slight increase from this point to the zone 

 of turbulence where the salinity dropped to 34.47«5,f at the surface. 



In Figure 15 isohalines for stations 27, 28, 29, and 30 are shown. At the 

 surface, there is a definite increase in salinity as the mid-Arabian Sea is 

 approached, and this is accelerated near tJie Red Sea outlet at the Gulf of 

 Aden. Furthermore, high salinity water, both from the Arabian Sea and from 

 the Red Sea, penetrated deeper in the western end of the section. Water with 

 salinity values of 35.00*^^ or higher was found to a depth of 900 to 950 meters 

 at station 27 (Fig. 22B), whereas at station 29 (Appendix A) it had descended 

 below 1400 meters. Station 30 south of Socotra Island was considerably shal- 

 lower than any of the other stations occupied but, nevertheless, showed the 

 highest salinity values of any station observed because of its location In the 

 center of the Red Sea outflow . 



The vertical distribution of salinity at stations 27, 28, and 30 Is shown in 

 Figure 22 (B, C, and D) . The curves for stations 27 and 28 are similar below 

 the zone of turbulence. At station 30, however, the extremely high salinity 

 water from the Red Sea reached a depth of 150 meters, and, from this depth to 

 the bottom, a uniform condition of somewhat lower salinity (around 35 .60'*?^-,) 

 prevailed . 



The meaning of the distribution of salinity values and their relation to the 

 various other masses comprising the water of the Indian Ocean will be discussed 

 in the next section under Temperature-Salinity relations. Identification of 

 water masses can be made by salinity content. These results are further borne 

 out by dissolved oxygen values which will be discussed In a later section. 



C . Temperature-Salinity Relations 



Figures 23, 24, and 25 depict the vertical distribution of temperature 

 plotted against salinity. In Figure 23, (A, B, and C), T-S curves for stations 

 1 , 3, and 5 along the 32° S . parallel are presented . The curves are very simi- 

 lar . At station 1, warm, highly saline, and less dense water was present in the 

 zone of turbulence down to around 30 meters depth. This station was close enough 

 to the Australian coast to be affected by the warm water current that sets south 

 along the coast; however, only the upper waters appear to be affected by this 

 current. Below 30 meters to about 150 meters, the waters gradually cooled and 



34 



