TURBULENT DIFFUSION OF TEMPERATURE 

 AND SALINITY: -AN EXPERIMENTAL STUDY 



Allen H. Schooley 



U.S. Naval Research Laboratory 

 Washing ton i B.C. 



ABSTRACT 



Stratified temperature and salinity conditions in 

 water have been established in a snriall laboratory 

 tank. A method for making measurements and cal- 

 culating the eddy diffusivities of temperature and 

 salinity for different controlled levels of turbulence 

 are described. The ratio of tenaperature and salinity 

 molecular diffusivities is on the order of 100. The 

 ratio of temperature and salinity eddy diffusivities, 

 for the most turbulent conditions studied, is 14. 



The dissipation of turbulent power density (P) due 

 to viscous friction was found to be on the order of 

 10^ larger than the power density (P') consumed 

 in changing the thickness of the pycnocline. The 

 experiments hint that P/P' may be relatively 

 constant over a range of turbulence. If this is 

 assumed to be true, there exists the possibility of 

 estimating temperature (D) and salinity (D') eddy 

 diffusivities by knowing the change of density, (Ap)^ 

 and (Ap)^, with time (-^t) for a given depth differ- 

 ence (Ah). Plots of D and D' in cm/sec vs« 

 (p!/^)i/2 = iio(Ap/At)'/2(^h) in sec-', are shown 

 where {r\) is the dynamic viscosity of water. 



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