PART II: BACKGROUND OF THE EXPERIMENT 

 Experiment Site and Schedule 



13. All essential equipment used in the surf zone experiments was 

 transported from CERC to the FRF in a truck. Setup on the beach and equipment 

 preparation and testing required approximately 1-1/2 days and took place over 

 3-4 September 1985. Main data collection was conducted over 5-9 September. 

 Disassembly of the base camp, including cleaning and repacking of equipment, 

 was done over 11-12 September. 



14. Experiments were performed from a base camp established on the 

 beach near the north property line of the FRF. Figure 2 is a plan-view sketch 

 of the base camp, FRF coordinate system, and the general physical arrangement 

 of the experiments. The area near the north property line was selected to 

 avoid possible contamination of waves, currents, and nearshore topography in 

 the vicinity of the experiments by the 600-m-long FRF pier located approxi- 

 mately 1,000 m to the south. An air-conditioned trailer located behind the 

 dune line provided a protective environment for the data recorders and other 

 sensitive instruments. 



15. These labor-intensive experiments were performed under highly 

 favorable sea conditions characterized by "clean" swell with moderate wave 

 heights. Figure 3 shows the wave height and period for 3-11 September 

 measured at FRF Gage 630, located in a depth of 18 m, and water level as 

 recorded on a gage located at the end of the pier . During the 5 days of 

 intensive data collection (5-9 September), the offshore wave conditions were 

 relatively constant, with the spectrally based significant wave height, H^^ , 

 in the range of approximately 0.4-0.5 m and the peak spectral period, Tp , in 

 the range of approximately 9-12 sec. At the base camp, long -crested waves of 

 cnoidal form were visually observed to arrive from slightly out of the 

 southern quadrant, producing a longshore current moving to the north with a 

 magnitude in the range of 0.1-0.3 m/sec. The wind was light (speed less than 

 approximately 5 m/sec (Mason, Birkemeier, and Howd 1987)) and directed 

 offshore. Table 1, adapted from Ebersole and Hughes (1987), sianraiarizes the 

 wind and offshore wave regime during the sand- trapping data collection period. 



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