sea, is directly proportional to the square of the wind velocity and is 

 at right angles to the wind regardless of (l) the depth to which the 

 wind current reaches and (2) the variations of eddy viscosity with 

 depth (Sverdrup, et al, 1942). In the northern hemisphere this trans- 

 port is directed 90° to the right of the wind. Thus a wind blowing to 

 the north in the nearshore region of a western coast creates a net 

 transport toward the coast in the upper layers. The boundary presented 

 by the coast, however, prohibits an eastward flow of the water. It 

 should be expected then that an accumulation of surface water would occur 

 in the coastal region, accompanied by a downward bending of the isothermal 

 and isohaline surfaces along the coastline (Fig 3A) . A wind blowing 

 toward the equator along the same coastline should create an offshore 

 transport in the upper layers and a corresponding upward bending of the 

 isothermal and isohaline surfaces along the coast (Fig 3B) . 



To examine the data from the Mission Beach site for Ekman transport 

 effects, daily averages of the continuous thermocline depth measured by 

 the isotherm followers were made. The 24-hour averages are desirable, 

 in that they minimize any influences of the diurnal and semidiurnal 

 tidal oscillations. Corresponding daily averages of the wind velocity 

 components parallel to the coast (along the WNW-ESE axis) were computed 

 from the hourly measured wind data and compared to the daily averaged 

 thermocline depths. Figure 4 reveals that the isothermal surfaces in 

 this coastal location respond to the wind in the manner predicted by 

 the Ekman theory. The mathematical relationship between the two curves 

 may be expressed as 



D = 36 - 2.6 W^^^ 



where D is the depth in feet to the center of the thermocline and W ^^ 

 is the wind velocity component in knots parallel to the coast, but from 

 the previous day. It is easily shown that the dependence of the gradient 

 depth on the first power of the wind velocity corresponds with the 

 dependence of the volume transported on the square of the wind velocity, 

 as predicted by theory. 



Wind Lag 



Figure 4 shows that there is a long-term, upward trend of 

 the thermocline which is accounted for, at least in part, by the wind. 



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