g* 



o 

 > 



4 



Si 



1° 



Run 



oOSUa 



Hi _ 









r 3 



sS 



-2| 



o 1 















0.5 m/s 





^^\ 



--___- 







9.0 



High Pass 

 Low Poll 



90.0 



100.0 BO.O 



Distance (ft) 



200.0 



290.0 























9.0 



50.0 



100.0 BO.O 



Distance (ft) 



200.0 



290.0 



Figure 3-7. Summary of wave transformation and cross-shore current 

 for Run A0814A 



kurtosis. Wave skewness increases as the waves become asymmetric in the 

 surf zone. 



Electromagnetic current meter. Spectral analysis results for the current 

 meters are given in Table C3, and time series results are given in Table C4, 

 contained in Volume II of this report. Table A 14 gives the channel numbers 

 associated with each current meter to relate the gauge positions and channel 

 numbers given in Tables C3 and C4. The odd-numbered channels are vertical 

 velocity, and the even-numbered channels are cross-shore velocity. The mean 

 cross-shore velocities for Run A0814A are shown in Figure 3-7 as vectors. 

 The current meters show a tendency for onshore flow above trough level and 

 offshore flow below trough level. Also, the velocity magnitude is much lower 

 outside the surf zone than inside. There is a marked decrease in the cross- 

 shore flow seaward of the bar. 



Identification of marginal data sets 



In general, the quality of the hydrodynamic data is considered to be good. 

 Care should be taken interpreting results from current meters that were located 

 near the mean water elevation and shoreward of the resistance gauges or on 

 the carriage, because these data were not filtered for being "in" or "out" of 

 the water. These data could be reanalyzed on a case-by-case basis using 

 capacitance wave gauges for filtering. Run A0916A should be viewed with 

 caution due to cross waves (standing waves in the y direction) during this run. 



Chapter 3 SUPERTANK Hydrodynamics 



71 



