Salinity and Oxygen 



Periodic determinations of salinity 

 throughout the 60-foot water column, 

 made during spring and summer, indicate 

 that there is rarely a variation of over 

 0. 24%ofrom the surface to the bottom, 

 and the average maximum vertical range 

 is only 0. 19 %o. Values are usually higher 

 at the sea floor and decrease towards the 

 surface. However, when stronger sum- 

 mer temperature gradients are present a 

 slight inversion in salinity structure 

 usually occurs. 



For the study of internal waves, 

 the vertical density and Vaisala frequency 

 (stability frequency) can be computed 

 from measurements of the salinity and 

 temperature structure. 



Sea-water samples collected at 

 the tower are analyzed to find dissolved 

 oxygen content. During spring and 

 summer, dissolved oxygen values range 

 between 4 and 8 ml/1. Higher values 

 include oxygen supplied by photo synthetic 

 action. 



Oxygen saturation may exceed 100 

 percent because of biological action and 

 changes in pressure and temperature. In 

 this supersaturated condition, internal 

 waves, turbulent motion, water heating, 

 or the further generation of gas by phyto- 

 plankton causes the release of oxygen 

 bubbles. These bubbles rise to the sur- 

 face or adhere to organisms. They can 

 attenuate underwater sound. 



Other studies of gas bubbles in the 

 water were made from samples collected 

 in situ by means of a large suspended 

 inverted funnel. Analyses revealed this 

 gas to be composed of: 2 14 to 18 percent; 

 CO 2 1 to 2 percent; CO to 1 percent; 

 CH4 to 1 percent; N2 78 to 85 percent. 



To determine salinity, oxygen, and water density, 

 water samples and temperatures are collected with 

 Nansen bottles at intervals from surface to bottom. 

 Water samples, taken during the summer and analyzed 

 with a laboratory salinometer, show nearly uniform 

 values from surface to bottom. For long-period 

 variations in salinity, an in situ salinometer is 

 mounted on a tripod out from the tower. Water sam- 

 ples, collected in water bottles, are analyzed for 

 oxygen by the Winkler method. 



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