-7- 



axis (positive if downstream) 



T = temperature 

 f = density 



-3 



0* = (f" f)" looo ^ where f> in units of g cm 

 Each of these quantities may be written as the sum of a time 

 mean (indicated by bar) and a deviation of a time mean (indicated 

 by prime). For example, for the cross stream velocity: u =u + u', 

 M. T - covariance in time of simultaneous cross 



current velocity and temperature 

 ^ S' - covariance in time of simultaneous cross 

 current velocity and density 

 The velocity components u and v were chosen in 

 such a way that there is no net (in any case a very small) mass 

 transport across the stream; i, e, ii c«f 0. Nevertheless, it is possible 

 to have a flux of "temperature" or density across the current due 

 to the eddy exchanges of water masses of different temperature 

 in a preferred direction. In our coordinate system: 



LcT =. «. 7" -♦- w.'T' ^^5; w. 



The covariance u'T' represents, if multiplied with the density p 

 and the specific heat c, the eddy flux of heat across the current. 

 In addition to the calculations at the surface, values of the heat 



