between the two ends of the channel is seen in Plate 51, described below.) 



106. The same hourly pulsing is visible in the currents at CM2S, CM2M, 

 and CM2B (Plates 35-40), and each pulse corresponds in phase, direction, and 

 amplitude with the forcing residual, TGI - TG3 . The meters at Site CM3 are 

 not strictly within the confines of the eastern entrance to Cerritos Channel 

 and are influenced by flow in the harbor. As a result, phase dependence at 

 the higher frequencies to residual TG6 - TG3 is less obvious, though the trend 

 over the interval and the time of current reversal are well correlated 

 (Plates 41-46) . 



107. Examination of currents at Site CM1 clearly illustrates the 

 "sloshing" occurring near the back of the channel. While the flow is ebbing 

 at both ends of the channel, both surface and bottom currents are reversing at 

 approximately 25-min cycles (Plates 47-50) . The migrating node evident in 

 Figure 13 may be associated with these reversals if its excursions extend as 

 far eastward as CM1 . 



108. Wave Gages LA4 and LB4 are located near the entrances to the chan- 

 nel, and, although not ideally sited, are good indicators of the hydraulic 

 potential differences of the ends. Plate 51 is the residual between 1A4 and 

 LB4. Each 25-min pulse in the currents is associated with a peak in the resi- 

 dual. A phase lag, likely due to wind effects and multiple reflections in the 

 numerous smaller basins, is evident. 



109. In the outer harbor, the predominant westerly sea breeze has a 

 more noticeable effect on surface currents. Plates 52 and 53 demonstrate the 

 reason for the easterly skewness of the rose plots at Sites CM6S and CM7S. 

 Rising tides cause weak, short-lived westerly flows or stronger flows to the 

 north or even south, perpendicular to the nearby breakwater. Additional anal- 

 ysis may reveal whether this represents flow through the breakwater itself or 

 vortices caused by currents transiting the nearby openings. Falling tides are 

 characterized by strong easterly currents predominantly aligned with the 

 breakwater. 



110. Current profile data in Appendix B verify the strong easterly flow 

 across the entire eastern entrance (Range P3) during ebb. Profiles across the 

 two western entrances at Ranges PI and P2 are flood dominated, rarely turning 

 directly south (seaward) even during peak ebb. Thus the typical tidal cycle 

 during the study can be characterized by flow through the western openings and 

 to some extent through the breakwater during flood. During ebb, the harbor 



38 



