16 
3 Selection of Wind and Tide 
Test Conditions 
Based on examination of wind data in Chapter 2, the most significant types 
of wind conditions with respect to harbor circulation were selected. The 
previous calibration and verification of the model considered only strong 
summer diurnal winds. 
In this report, four wind conditions are considered. The first is a summer 
condition characterized by the calibration period in which winds exhibit a 
typical diurnal cycle with strong afternoon onshore winds. This is called the 
"existing condition." It was of interest to contrast this condition with a 
"no-wind" condition to help understand the effect of winds on harbor 
circulation and provide information about circulation when winds are low, 
though the diurnal wind cycle is the dominant wind pattern. Next the 
calibration wind field was shifted in time by 10 hr so the maximum wind 
speeds coincide with the long ebb flow of higher high water to lower low 
water rather than the slower flood flow conditions of lower high water to 
higher high water used in calibration. This is identified as Case 1. Figure 11 
shows this wind condition, with time measured from 0000 hr on 1 January 
1987 (Pacific standard time). Note 5232 hr corresponds to 0000 hr on 
7 August 1987. Direction shown, in degrees from north, i.e., 0 deg is from 
north, +90 deg is from east, and -90 deg is from west, etc., is the direction 
from which the wind was blowing. The measured water surface elevation at 
the offshore boundary used in the calibration is also shown in Figure 11. 
Following Case 1, two wind conditions (Cases 2 and 3) associated with strong 
frontal systems were investigated. Case 2 was for winds from the southeast 
and Case 3 for northwest winds. These selected events are described in detail 
in Chapter 5. Tidal conditions used for Cases 2 and 3 were the same as for 
Case 1 (and the model calibration) since no prototype boundary tidal 
conditions were available for these events. This was probably not significant 
for Case 2 since wind was from the southeast, from the ocean toward the 
harbors, as calibration winds were from ocean to harbors. For Case 3, winds 
were from the northwest, from the harbors to the ocean, so boundary effects 
may be present due to the significant change in wind-field orientation. 
However, the focus of the study was on harbor circulation behind the 
breakwaters, distant from the boundary, which should permit a reasonable 
Chapter 3 Selection of Wind and Tide Test Conditions 
