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Mr. Patrick Caldwell Hawaii Liaison NOAA/NESDIS Data Center Photo: Debbie and Kimbal Milikan.

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Presentation on theme: "Mr. Patrick Caldwell Hawaii Liaison NOAA/NESDIS Data Center Photo: Debbie and Kimbal Milikan."— Presentation transcript:

1 Mr. Patrick Caldwell Hawaii Liaison NOAA/NESDIS Data Center Photo: Debbie and Kimbal Milikan

2 Goddard-Caldwell Data Set Surf Climatology Analysis and Results

3 Surf Information: Planning and Protecting Life and Property - Recreation - Commercial Ventures - Engineering - Transportation - Research - Gov’t Coastal Zone Management - Litigation - Surf forecast validation User Community Photo: Patrick Holzman, Location: Kamalino Drive, Kailua, Oahu, November 2003 Motivation Goddard-Caldwell surf database the most requested dataset from NOAA Hawaii Data Office

4 Regional Data Added to the NOAA Posterity Archive Number Of Unique Acquisitions (NODC Accessions) *since 1998 Updated Dec 28, 2005

5 Who Provided Data? Number Of Unique Acquisitions Updated Dec 28, 2005 Since 1998

6 Regional Data Services Number of Unique Requests Data Category 265 requests since 10/2001 These are hands-on requests, not automatic transfers from FTP/WWW. Updated Dec 28, 2005

7 Services: To Where? Updated Dec 28, 2005 Hands-on since 10/2001

8 Services: What Parameters? Updated Dec 28, 2005 Hands-on since 10/2001

9 Primary Surf Data Sources: Buoys and Surf Observations Buoys Pros: - explicit measurements - gives statistical distribution (energy spectrum) - around the clock Cons: - not surf, offshore waves - technical break downs - limited length - buoy since buoys since Kailua (8/00), Waimea (12/01) Dept. of Oceanography University of Hawaii Kailua Buoy

10 Surf Observations Primary Surf Data Sources Pros: - explicit surf heights - inherent knowledge base - longest, most continuous (daily data since 8/1968) - more locations Cons: - subjectivity - only daylight - limited statistical distribution of each report (no spectrum)

11 Observations in history/science Hawaiian language: 135 words: moods of sea and surf 149 words: wind 87 words: rain 27 words: clouds Harold Kent, “Treasury of Hawaiian Words in 101 Categories”

12 Beaufort Wind Scale Developed in 1805 by Sir Francis Beaufort of England Visual observations to estimate wind speeds at sea on a scale of 1-12 Other Observations used In science: rogue waves

13 Waimea buoy Kailua buoy Observational Network Primary reporting locations North Shore Observations, 1968-present Goddard-Caldwell Dataset

14 What is in the Goddard-Caldwell Database? -Daily value - for given range, upper end of range - units: Hawaii Scale - highest report of day -North Shore special case - represents location of highest reported breakers Regardless of Height Scale -Course resolution -difficulties to define temporal variability -difficulties to define where along wave front the height refers to -which reef is being referred to? -published literature shows tendency for underestimation of surf heights

15 What is the range given in surf reports? (if report given as ocn 15, what does that mean?) 29 November, 2004 Temporal Variability

16 29 November, 2004 Benchmarks (surfers) Rayleigh Wave Distrubtion Frequency of Occurrence Wave height Most frequent Average height Significant height (H1/3) H1/10 H1/100 Surf report: H1/3 to H1/10, ocn H1/100

17 Simulating Waves Nearshore (SWAN) Model -Large variations in surf height along a given shoreline -Largest breakers occurs in zones of high refraction - this is where surfers go - this is where reports are made Incident 2.5 m, 14 second from 315 o 315 o Incident 6.5 m, 19 second from 317 o 20m isobath Height (m) Spatial Variability

18 What makes a dataset valid? Consistency

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21 Methodology: buoy-derived, shoaling-estimated surf height: Data: - Daily Surf Observations - Buoy ( ) - Waimea Buoy (2002) maximum H b between 7am-5pm (07-22Z for 51001) * Conservation of energy flux * Ignores refraction, diffraction, bottom friction, currents, wave-wave interactions, and wind Following Komar and Gaughan, 1973 Days removed from data: - April - September - strong trades (>22 knots) - dominant period < 12 sec

22 Temporal Consistency Test Surf Observation minus Buoy-estimated Surf Height Absolute heights unimportant Ratio = Difference / Estimated Height

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26 Error Estimates Magnitude of Error increases with height Average Error ~15%

27 Wave Climatologies Most cited reference: MOBERLY,R.J., and CHAMBERLAIN,T., Hawaiian Beach Systems. Honolulu, Hawaii: University of Hawaii, Hawaii Institute of Geophysics Technical Report No. 64-2, 95p.

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30 Climatology From Buoys

31 Winter Fall SpringSummer Ave. Sig. Height (m) TOPEX Wave Height Climatology From Altimeters THE OCEAN ATLAS OF HAWAII (Flament et al, 1996)

32 Surf Climatology Caldwell, 2005, JCR

33 North Shore Surf Direction Climatology Caldwell, 2005, JCR No. Days Per Month (> 2 Hsf)

34 Surf Climatology Caldwell, 2005, JCR

35 Photo:Jamie Ballenger Waimea, Jan. 25, 2003, HSF=25 Translation from Hawaii Scale to Trough-to-Crest Heights Future Talks:

36 NWS High surf advisory NWS High surf warning Empirical Estimate of Surf Height given Offshore Height and Period Caldwell and Aucan, 2006, JCR

37 5’ Photo: E.Aeder Surfer: P.Cabrina, Note: Billabong XXL 2004 winner, as 70’ Peahi (Jaws), January 10, 2004, Hsf=27 Caldwell-Aucan Formula, Given 17’ 17sec, H1/3 = 40’ H1/10 = 52’ H1/100 = 70’

38 mahalo, aloha, a hui hou Photo: Patrick Holzman Acknowledgements Jerome Aucan Waimea buoy data, formula, review Steve Businger Review, plots Mark Merrifield, Chris Conger Review Surf Observations Surf News Network C&C Lifeguards Larry Goddard ( ) Randy Rarick, Peter Cole, Bernie Baker, Albert Benson Pat’s support: Garrett McNamara, Clark Abbey, Ian Masterson, Kaleo Ahina, Jerome Aucan, Nathalie Zilberman, Thomas Decloedt, Cedric Chavanne, Sean Johnston, Eric Grossman, Yvonne Firing, Kimball Millikan, Rob Yonover, AJ Harris, Jeff Cotter, Robert Burke, and websites : Claudia Ferrari’s Daily Surf News, Surfline, and Jamie Ballinger’s Hawaiian Watershots


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