402 BOUNDARIES OF THE SEA 



restricts all heat radiation effects to a surface layer a few meters 

 thick. 



When we can predict the interior state in terms of these forces, 

 we shall have attained a real understanding of the physics of the 

 ocean. Most of the earlier research in physical oceanography has 

 been diagnostic, trying to relate different quantities such as the 

 mass and velocity fields. These investigations are certainly most 

 valuable and have supplied oceanography with many valuable 

 theoretical tools, such as the "dynamic method" for computing 

 ocean transports. They can, however, give us only part of the 

 solution, which must come from models in which the boundary 

 processes are the primary forces. 



The first step is, of course, the study of the boundary processes 

 themselves, and here much remains to be done. At present we try 

 to construct a map of the yearly mean transport of water, of 

 momentum, and of heat through the surface layer of the oceans. 

 We cannot, considering all sources of error, give values correct 

 within more than a factor of 2. Such uncertainty concerning the 

 basic forces will prevent us from checking any theoretical model 

 very exactly. How should we then be able to improve our present 

 computations of these functions? 



It seems that some new possibilities have now opened by the 

 construction of reliable and accurate devices which directly 

 measure the velocity and temperature fluctuations and their cross 

 correlations in the sea. The possibility of making direct measure- 

 ments of the turbulent momentum and heat transfer in the ocean 

 surface layer by a hot-wire technique has been demonstrated by 

 Dr. Kolesnikov at this Congress, and it should be possible to 

 develop the method further. Direct measurements of the turbulent 

 heat flux in the surface layer of the sea seem to be advantageous. 

 In older computations based on measurements in the surface 

 layer of the atmosphere, the total heat flux is given by a number 

 of different processes: radiation, turbulent transfer, transfer of 

 latent heat by evaporation and precipitation. It is difficult to 

 estimate all these terms very accurately. If one measures in the 

 sea a few meters below the surface, there is only one mechanism 

 responsible for the heat transport, the turbulence, and the problem 



