1. Monterey Buoy 46042
LT Karen Wingeart

2. Outline of Presentation
Buoy characteristics
Measurements taken
Data discussion
Conclusions

4. Parameter
Range
Freq
Avg
Resol
Accuracy
Wind dir
0-360°
1.0 Hz
8 min 1°
±10°
Wind spd
0-62 m/s
0.1 m/s
±1.0 m/s
Wave ht
0-35 m
2.56 Hz
20 min
0.1 m
±0.2 m
Wave pd
0-30 sec
1 sec
±1.0 sec
Spectra
0-999 m2/Hz
0.01 Hz
±0.01 Hz
Wave dir NA

5. Measurements taken Wind Direction Wind Speed Wave Energy
Significant Wave Height
Mean Direction
Directional Spread (R1)
+ = [2(1–R1)]1/2 , R1 = [a12+b12]1/2

6. Normalized Energy vs. 

7. Relative Energy vs. Period

8. Composite contour plot, white lines are missing data
Composite contour plot, white lines are missing data. Used to initially identify swell events. Did not look at data >0.15 Hz. Swell events have periods <0.15 Hz.

9. Energy spectrum related to energy of waves
Energy spectrum related to energy of waves. Just prior to the swell event. Two peaks, EN = 0.6 m^2/Hz at T = 14s, & 10s.

10. At the beginning of the swell event, peak en = 15 m^2/Hz at 14 s period.

11. Peak of swell event, 100 m^2/Hz, 16 s period.

12. Wind directions from northeast to northwest
Wind directions from northeast to northwest. Local winds from 2 m/s – 12 m/s. Measured SWH and calculated SWH from integrated Pierson-Moskowitz spectrum.

13. Significant Wave Height
The relationship between wind and Hs can be found by integrating the Pierson-Moskowitz spectrum:
E(f)=g2/((2)4f5)exp[-(2fU/g)-4]
variance = 0E(f)df = U4/(4g2)
Hs = 2(/)1/2(U2/g)
where =8.1010–3 and =0.74 (Hasselmann et al., 1973).
Pierson-Moskowitz spectrum = as wind speed increases, wave period increases, energy increases, and slope of right edge of spectra->f^-5.

14. Measured Dominant wave period at peak freqs and calcuated dominant wave period.

15. Peak Frequency
Peak Period estimated from local winds using relationship from Hasselmann et al. (1973).
fp = g/(2U)

16. The cloud band north of Monterey Bay moved southeastward, in the direction of the swells. This system was probably the source of the waves.

17. Conclusions
Swells generated by distant storm from Northwest Pacific as evident by large energy increases and directional properties.
Data obtained from beware of archive gap!
Matlab helpful in processing data.
Additional study of wind-wave interaction needed with more accurate wind data near buoy site.
Conduct study during months of increased storm activity for more swell events, ie. October.

18. Questions???