must be solved. Another problem, not specifically associated with the 

 oceans, but one which must be resolved before design can proceed, is 

 whether point or continuous observations are desired. Finally depth 

 measurement is a problem which must be regarded as an integral part 

 of not only temperature measurement but also of any other variable 

 being measured below the ocean surface. All of these variables must 

 be positioned with regard to time, latitude, longitude, and depth. 



Temperature is used, directly and indirectly, to describe a wide 

 variety of phenomena and processes taking place in the oceans. At the 

 Hydrographic Office, temperature values are used in the following 

 applications. 



1. Description of the environment 



Sea water temperature can affect the performance of equipment 

 and personnel. 



2. Sound velocity computations 



Of the three variables, temperature, salinity, and pressure, that 

 affect sound velocity, temperature has the greatest effect. 



3. Calculation of density 



Density is a factor in buoyancy problems. 



4. Electrical conductivity of sea water 



Temperature and salinity are the variables that affect electrical 

 conductivity. 



5. Current studies 



Where current measurements are lacking, much information can 

 be deduced from a study of the spatial and temporal distribution of 

 temperature. 



6. Temperature prediction 



Underwater sound transmission is closely dependent upon the 

 thermal structure of the ocean. The development of sonar prediction 

 techniques and RAFOS systems requires a thorough understanding of 

 the thermal structure and the changes occurring therein. 



Ill -2 



