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

Mr. Patrick Caldwell
Hawaii Liaison
NOAA/NESDIS Data Center
Photo: Debbie and Kimbal Milikan
Goddard-Caldwell
Data Set
Analysis and Results
Surf Climatology
User Community
Motivation
Surf Information: Planning
and Protecting Life and Property
- Recreation
- Commercial Ventures
- Engineering
- Transportation
- Research
- Gov’t Coastal Zone
Management
- Litigation
- Surf forecast validation
•Goddard-Caldwell surf database
the most requested dataset from
NOAA Hawaii Data Office
Photo: Patrick Holzman, Location: Kamalino Drive, Kailua, Oahu, November 2003
Regional Data Added to the
NOAA Posterity Archive
100
90
80
70
Number
Of Unique 60
Acquisitions50
(NODC
Accessions) 40
30
20
10
0
Physical
Biological
Chemical
Geophysical
*since 1998
Updated Dec 28, 2005
Who Provided Data?
100
90
80
70
Number
Of Unique 60
Acquisitions50
40
30
20
10
0
EDU
Since 1998
GOV
ORG
COM
PUB
MIL
Updated Dec 28, 2005
Updated Dec 28, 2005
Regional Data Services
Data Category
Number
of Unique
Requests
265 requests
since 10/2001
Chemical
Geophysical
Meteorologcal
Biological
Physical
200
180
160
140
120
100
80
60
40
20
0
These are hands-on requests, not automatic transfers from FTP/WWW.
Services: To Where?
120
100
80
60
40
20
0
EDU
Hands-on since 10/2001
COM
GOV
PUB
MIL
Updated Dec 28, 2005
Services: What Parameters?
de
s
Ti
eo
l
og
ica
l
es
G
Sp
ec
i
lit
y
Q
ua
ip
H
20
re
c
hy
in
d/
P
W
of
Pr
Hands-on since 10/2001
Ba
t
ile
es
TS
-w
av
nt
s
Bu
oy
Cu
rr
e
Su
rf
90
80
70
60
50
40
30
20
10
0
Updated Dec 28, 2005
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 51001 since 1981
- buoys 51002-4 since 1984
- Kailua (8/00), Waimea (12/01)
Dept. of Oceanography
University of Hawaii
Kailua Buoy
Primary Surf Data Sources
Surf Observations
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)
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”
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
Observational Network
Goddard-Caldwell
Dataset
North Shore
Observations,
1968-present
Waimea
buoy
Kailua
buoy
Primary reporting locations
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
Temporal
Variability
29 November, 2004
What is the range given in surf reports?
(if report given as 10-12 ocn 15, what does that mean?)
Most frequent
Average height
Significant height
(H1/3)
H1/10
H1/100
Wave height
Frequency of Occurrence
Rayleigh
Wave
Distrubtion
Surf report: H1/3 to H1/10, ocn H1/100
29 November, 2004
Benchmarks
(surfers)
Spatial Variability
Incident 2.5 m, 14 second from 315o
20m
isobath
Simulating Waves Nearshore
(SWAN) Model
315o
Height (m)
Incident 6.5 m, 19 second from 317o
-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
What makes a dataset valid? Consistency
Methodology:
buoy-derived, shoaling-estimated surf height:
Data: - Daily Surf Observations
Following Komar and Gaughan, 1973
Hb
4 /5

H [(1 /
o
g )( gP / 4  )]
2 /5
(1)
where:
Hb = shoaling-only predicted wave height at breaking
Ho = deep water significant wave height
P = dominant wave period
g = gravity
- Buoy 51001 (1981-2002)
- Waimea Buoy (2002)
maximum Hb between 7am-5pm
(07-22Z for 51001)
Days removed from data:
* Conservation of energy flux
* Ignores refraction, diffraction, bottom friction, currents,
wave-wave interactions, and wind
- April - September
- strong trades (>22 knots)
- dominant period < 12 sec
Temporal Consistency Test
Surf Observation minus Buoy-estimated Surf Height
Ratio =
Difference /
Estimated
Height
Absolute heights unimportant
Error Estimates
Magnitude
of Error
increases
with height
Average
Error ~15%
Wave Climatologies
Most cited reference:
MOBERLY,R.J., and CHAMBERLAIN,T., 1964. Hawaiian Beach
Systems. Honolulu, Hawaii: University of Hawaii, Hawaii
Institute of Geophysics Technical Report No. 64-2, 95p.
Climatology
From
Buoys
TOPEX 1992-95
Wave Height
Climatology
From Altimeters
Fall
Winter
THE OCEAN ATLAS OF HAWAII
(Flament et al, 1996)
Spring
Summer
Ave. Sig. Height (m)
Surf Climatology
Caldwell, 2005, JCR
North Shore Surf Direction Climatology
20
18
16
No.
Days
14
Per
Month 12
(> 2 Hsf) 10
W-WNW
WNW-NW
NW-NNW
NNW-N
N-NNE
8
6
4
2
0
SEP OCT NOV DEC
Caldwell, 2005, JCR
JAN
FEB
MAR APR
MAY
Surf Climatology
Caldwell, 2005, JCR
Future Talks:
Translation from Hawaii Scale to Trough-to-Crest Heights
Waimea, Jan. 25, 2003, HSF=25
Photo:Jamie Ballenger
Empirical Estimate of Surf Height given Offshore Height and Period
NWS
High surf
warning
NWS
High surf
advisory
Caldwell and Aucan, 2006, JCR
Peahi (Jaws), January 10, 2004, Hsf=27
Caldwell-Aucan Formula,
Given 17’ 17sec,
H1/3 = 40’
H1/10 = 52’
H1/100 = 70’
5’
Photo: E.Aeder Surfer: P.Cabrina, Note: Billabong XXL 2004 winner, as 70’
Acknowledgements
Surf Observations
Jerome Aucan
Surf News Network
Waimea buoy data, formula, review
C&C Lifeguards
Steve Businger
Larry Goddard (1968-1987)
Review, plots
Mark Merrifield, Chris Conger
Review
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
mahalo,
aloha,
a hui hou
Photo: Patrick Holzman