PART V: CONCLUSIONS 



113. A synoptic data collection effort at LA/LB Harbors was completed 

 that provides adequate data to calibrate and verify a 3-D numerical model of 

 tidal circulation. Three months of tidal data, three months of wind data, one 

 month of current data, and half- tidal cycle current profiles were obtained 

 throughout the harbor. Project requirements and schedules as directed in the 

 Management Plan were fully met. 



114. Conclusions resulting from the study are: 



a. Use of a common mean water surface as a datum for synoptic 

 tidal measurements over limited space and duration provided 

 reasonable results and is a cost-effective alternative to 

 independent leveling of offshore gages. 



b. Tidal circulation in LA/LB Harbors during the collection 

 period was characterized by low velocities (rarely exceeding 

 0.5 ft/sec) and small-scale spatial and temporal variations, 

 including frequent flow reversals in a vertical profile. 

 Oscillations in the current were evident at periods as short 

 as 30 min resulting from resonance of energy at frequencies 

 not normally associated with tidal constituents reflecting 

 from harbor boundaries. 



c. Flow in the Cerritos Channel was basically divergent/ 

 convergent from the two openings, but sufficient amplitude and 

 phase differences existed to result in a net circulation 

 counterclockwise. A migrating node existed at the back of the 

 channel . 



d. In the outer harbor, locations near the breakwater experienced 

 significant net transport because of unequal ebb and flood 

 currents. The harbor tends to fill from the west during flood 

 and drain to the east during ebb. This may be a seasonal 

 phenomenon related to the relative phase between the tides and 

 the daily sea breeze. 



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