The climatology simulations were then made at different tide stages and currents.
Conditions were selected based on analysis of data, which showed that slack currents in the
inlet occur near the time of mean high water and mean low water and maximum currents
occur near the time of MTL. Ebb and flood currents were obtained from an ADCIRC
simulation and interpolated onto the STWAVE grid. "Peak" currents, on the order of 0.8-
0.9 m/sec, were selected for a typical mean tide cycle and do not represent maximum
conditions that can occur at Grays Harbor. (The maximum current at the entrance during
the first deployment period was 1.7 m/sec.) The tide range was approximately 2.1-2.2 m,
which is equivalent to the mean tide range, whereas the spring tide range is on the order of
3 m. These simulations demonstrate the influence of water level and current on waves in
the Grays Harbor entrance. Figures 9 and 10 show differences in wave height at Station 2
for the various currents and water levels versus wave heights with no current or water level
variation. Water level has minimal influence on wave height in the inlet entrance under
most conditions. Flood currents increase wave height at Station 1 (due to the ebb shoal
bathymetry redirecting flow offshore), but reduce wave height at Stations 2 and 3. Ebb
currents cause a significant increase in wave height at all stations for most wave conditions.
2.0
20 1
Ebb vs No Flow
Station 2
Increasing Period
Flood vs No Flow
1.5
16 8
1.0
12 6
Fig 9. Influence of current
0.5
on wave height
8 4
(Each group of 30 wave
0.0
conditions reflects 5 wave
periods and 6 wave
4 2
-0.5
directions)
H=2.5 m
H=0.5 m
H=1.5 m
H=5.0 m
H=6.5 m
H=3.5 m
-1.0
0 0
0
30
60
90
120
150
180
Wave Condition Number
2.0
20 100
Station 2
MHW vs MTL
1.5
MLW vs MTL
16 80
Increasing Period
1.0
Fig 10. Influence of water
12 60
level on wave height
0.5
(Each group of 30 wave
8 40
conditions reflects 5 wave
0.0
periods and 6 wave
directions)
4 20
-0.5
H=3.5 m
H=1.5 m
H=0.5 m
H=6.5 m
H=5.0 m
H=2.5 m
-1.0
0 0
0
30
60
90
120
150
180
Wave Condition Number
Cialone & Kraus
9
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