runs conducted on 22 and 23 September, indicating that the longshore current 

 flowed from south to north (toward the rip current) on the majority of 

 experiment days. The streamers were observed to reverse direction only during 

 one TSM run on 23 September. As expected, the mean longshore current 

 (y-component) is larger than the mean cross-shore current (x-component) . The 

 standard deviation of the cross-shore component (<j v of x-component) is larger 

 than the standard deviation of the longshore component (ct v of y-component) , 

 because of the oscillatory motion of incident waves. 



Waves and Water Levels 



40. The analysis procedure for obtaining wave and water level para- 

 meters from the photopole record is described in detail by Ebersole and Hughes 

 (in preparation). In summary, the digitized time series was cleaned through 

 visual inspection and then filtered to remove long-period wave motions. The 

 filter eliminated oscillations with periods greater than 30 sec and preserved 

 oscillations with periods less than 16 sec; waves with periods between 16 and 

 30 sec were partially retained (Ebersole and Hughes, in preparation). Table 5 

 presents various statistical properties of the filtered record corresponding 

 to each trap deployment interval (6, 7, or 8 min) in the six TSM runs for 

 which photopole data were analyzed. Listed wave properties were calculated 

 through an individual wave zero-down crossing method. 



Sand Transport 



Consistency runs 



41. Seven consistency tests were conducted during SUPERDUCK, and 

 vertical distributions of the fluxes measured with the two closely spaced 

 traps, designated by "shoreward" and "seaward" locations, have been plotted to 

 the same scales for comparison (Figures 11 through 17). Four of the consis- 

 tency comparisons were conducted as a part of TSM runs 8609201500 and 

 8609211345 (Figure 13, 14, 16, and 17) and are differentiated with the 

 notation " -1" and "-2" at the end of the run number. The shape of the 

 vertical distributions of sand flux measured during SUPERDUCK varied more 

 between the shoreward and seaward traps than those measured during DUCK85 (see 



36 



