breakwater gap. For the 3D case, net flow is smaller and from the ocean into 
the harbors through Angel’s Gate and out through Queen’s Gate and the east 
breakwater gap. Thus 2D model results, in terms of flow volumes at the 
three harbor entrances, indicate a stronger net circulation to the east than 
given by the 3D model. This is contrary to the normal expectation that the 
inclusion of net eastward-directed winds in the 3D model would promote a 
stronger net circulation to the east. This behavior may be explained by the 
fact that the relatively deep nature of the harbors permits the return flow of 
water to Angel’s Gate and Queen’s Gate, rather than major net movement 
toward the east breakwater gap, as would be true for a shallow harbor. 
Table 2 
Distribution of Net Flow Into (+) or Out of (-) Harbor as a Percent 
of Total Flow Volume Into Harbor 
ei ie en ee aa ee 
rr cer Ser a es 
Prete eG Sea co 
Case 1 versus Existing Condition 
The Case 1 shift of 10 hr in the timing of wind (so that maximum winds 
occurred during strongest ebb flow) produced changes in discharges in the outer 
harbor (Range 5, Figure 16 and Plate 31) and at harbor gates (Ranges 1, 6, and 
7, Plates 27, 32, and 33, respectively). Other discharge ranges in the inner 
harbor showed no change (Plates 28-30). Positive discharge is eastward at 
Ranges 4 and 5, and northward at the other ranges. Downward arrows in Figure 
16 indicate when maximum wind was blowing for each condition. It is clear that 
at Range 5, whenever the wind velocity for a particular condition was at its peak, 
the discharge was greater than the discharge for the other condition. Comparing 
the two curves, one can estimate that the net effect over several days is close to 
zero; i.e. the occurrence of westerly winds relative to the phase of tidal currents 
has no significant effect except in the short term. When strong westerly winds 
occur during flood flows, discharges are increased slightly through Angel’s Gate 
and decreased at the east breakwater gap, enhancing eastward flow. When strong 
westerly winds occur during ebb flow, ebb discharge is decreased at Angel’s Gate and 
increased at the east breakwater gap, once again enhancing net eastward flow. 
Figure 17 shows locations where current magnitude and direction measurements 
were sampled for the three layers. Layers 1, 2, and 3 correspond to bottom, 
mid-depth, and surface currents, respectively. Examination of Plates 34-54 shows 
only small changes in velocities and direction. Plates 55-58 indicate no change in 
tidal elevations. The existing condition data plots directly on top of the Case 1 
data. Plates 59-70 show the current vector snapshots for various tidal conditions 
Chapter 5 Model Simulations 
