1. Contributing to the Prediction Coastal Flooding:
Casey Thornbrugh
Science Research Mentors: Amanda H. Lynch & Elizabeth N. Cassano
Cooperative Institute for Research in the Environmental Sciences
University of Colorado, Boulder
Science Writing Mentor: Nancy Dawson
Significant Opportunities in Atmospheric Research and Science
University Corporation for Atmospheric Research
Simulating Wave Heights and Directions
Along the Coast Of
Barrow, Alaska
Contributing to the Prediction
Coastal Flooding:

2. Background
The Alaska North Slope Region
Research Problems
Methodology
Data Used
Description of SWAN wave simulations
Results
Conclusions

3. The Alaska North Slope Region
William Manley
INSTAAR
100 meter pixel size
Digital Elevation Model of the Alaska North Slope
Beaufort Sea
Chukchi Sea
The Alaska North Slope Region

4. Coastal flooding models incorporating tidal fluctuations and storm surges, have often produced results where the simulation of coastal flooding was below the actual
observed coastal flooding.
There is a lack of raw data consisting of wave height measurements and wave directional data offshore or in the Barrow coastal region.
The Research Problems

5. The Naval Arctic Research Lab (NARL) October 1963
(Approximately 1.5 miles north of Barrow)
October 1963
Photo courtesy of Grace Redding, 1963

6. October 1963 Flood Extent with 12 and 16 Foot Contours for Barrow, Alaska
Flood map constructed by Leanne Lestak, William F. Manley, and James Maslanik,
August The October 1963 flood extent was mapped by Hume and Schaulk, 1967.
Chukchi
Sea

7. Purpose The purpose of this project is the use of the
Simulation of Waves Near shore (SWAN) model to
simulate wave heights and directions offshore and in
the Barrow coastal region.
Incorporating the results from from the SWAN model
with a storm surge model for Barrow, will allow a total
flood height to be simulated and compared with
past, observed coastal flooding.
Purpose

8. Bathymetry of the Barrow Coastal Region
Bathymetry map of the Barrow coastal region
Image provided by Leanne Lestak
Cooperative Institute for Research in Environmental Science
University of Colorado, Boulder
Barrow
Chukchi
Sea
Beaufort
Bathymetry of the Barrow Coastal Region

9. Data with data from NOAA and NGDC
Bathymetry of the Barrow coastal region compiled
with data from NOAA and NGDC
Daily and average monthly sea ice concentration
data from NSIDC
Daily average wind speeds and directions for 11
historical storms from the Barrow NWS office
Hourly wind speeds and directions for the 29 July
2003 storm from the Barrow NWS office
The computational grid will represent an area 390 by
390 km over the Alaska North Slope coastline and
the Chukchi/Beaufort Seas.
Data

10. Bathymetry Input Grid for SWAN
Image provided by Leanne Lestak
Cooperative Institute for Research in Environmental Science
University of Colorado, Boulder

11. The Simulation of Waves Near shore Model
SWAN is a wave simulation model specifically
designed to simulate wave heights for
shallow coastal areas.
Input data for SWAN includes:
Wind direction and speed
Location and shape of the shoreline
Bathymetry of the coastal seafloor
SWAN

12. The Simulation of Waves Near shore Model
SWAN is a wave simulation model specifically
designed to simulate wave heights for
shallow coastal areas.
Additional input data for SWAN included:
Sea ice edge
Prescribed boundary conditions (wave height & direction)
SWAN

13. The Simulation of Waves Near shore Model
SWAN
The Simulation of Waves Near shore Model
SWAN wave simulations were run for:
11 historical late summer & fall storms occurring
from 1 August 1950 through 31 August 2000
A. Input of a constant wind speed and direction for each storm
B. Added sea ice edge
C. No prescribed boundary conditions

14. Results (part one) SWAN wave simulation model simulated wave
heights and directions offshore and in the Barrow
coastal region
High winds from any direction produced high
waves offshore.
High westerly winds produced the highest waves in
the Barrow coastal region.
Results (part one)

15. Results (part one) Sea ice-edge covering greater than 50% of the sea
surface moderately reduced the wave heights
offshore and in the Barrow coastal region.
Results (part one)

16. 24 October 1998 Wind speed: 17.0 m/s
Wave heights (cm)
wave direction (degrees x 10 ^ -1)
Wind speed: 17.0 m/s
Wind direction: 70° (East/Northeast)
High easterly winds
Wind direction
Wave direction
Alaska North Slope

17. 20 September 1986 Wind speed: 13.9 m/s
Wave heights (cm)
wave direction (degrees x 10 ^ -1)
Wind speed: 13.9 m/s
Wind direction: 225° (Southwest)
20 September 1986
Moderate southwesterly winds
Wind direction
Wave direction
Alaska North Slope
Alaska North Slope
Alaska North Slope

18. 3 October 1963 Wind speed: 17.4 m/s Wind direction: 270° (West)
Wave heights (cm)
wave direction (degrees x 10 ^ -1)
Wind speed: 17.4 m/s
Wind direction: 270° (West)
3 October 1963
High westerly winds
Wind direction
Wave direction
Alaska North Slope
Sea ice edge

19. Wave heights (cm)
wave direction (degrees x 10 ^ -1)
Wind speed: 14.7 m/s
Wind direction: 68° (East/Northeast)
24 August 1950
Moderate easterly winds with extended sea ice-edge
Wind direction
Wave direction
Alaska North Slope
Sea ice edge

20. The Simulation of Waves Near shore Model
SWAN
SWAN wave simulations were run for:
II hourly time steps for the 29 July 2003 storm
A. Input of the average wind speed and direction for every 6 hrs
B. Wind data 7 PM 28 July through 7 AM 30 July (Alaska time)
C. Prescribed boundary conditions
D. No sea ice edge

21. Results (part two) SWAN wave simulation for 29 July 2003 produced
maximum offshore wave heights of 5 to 5.6 m
consistent with the NWS Barrow office marine
forecast of waves 5 to 6 m for this storm.
Simulation produced maximum wave heights of 4.6
m, consistent with the 4 to 5 m waves observed
near shore by the NWS.

22. Boundary conditions permitted a realistic lag time for
changes in wave direction in response to changes in
the wind direction.
Results (part two)

23. 29 July AM
Wave heights (cm)
wave direction (degrees x 10 ^ -1)
Wind speed: 10.3 m/s
Wind direction: 211° (South/Southwest)
Boundary conditions: wave height = 0.8 m
wave direction = 225° (Southwest)
Wind direction
Wave direction
Alaska North Slope

24. Wave heights (cm)
wave direction (degrees x 10 ^ -1)
Wind speed: 15.0 m/s
Wind direction: 251° (West/Southwest)
Boundary conditions: wave height = 1.8 m
wave direction = 215° (Southwest)
29 July AM
Wind direction
Wave direction
Alaska North Slope

25. 29 July 2003 1 PM Wind speed: 16.5 m/s Wind direction: 270° (West)
Wave heights (cm)
wave direction (degrees x 10 ^ -1)
Wind speed: 16.5 m/s
Wind direction: 270° (West)
Boundary conditions: wave height = 3.3 m
wave direction = 245° (West/Southwest)
29 July PM
Wind direction
Wave direction
Alaska North Slope

26. Wave heights (cm)
wave direction (degrees x 10 ^ -1)
Wind speed: 9.1 m/s
Wind direction: 289° (West/Northwest)
Boundary conditions: wave height = 3.0 m
wave direction = 270° (West)
30 July AM
Wind direction
Wave direction
Alaska North Slope

27. Knowing the contribution of waves to coastal flooding will improve the ability to predict the total flood heights.
This information exposes areas of Barrow that are vulnerable to flooding and allows community members to develop ways to protect these areas.
Conclusions

28. Acknowledgements Science Research Mentors:
Amanda H. Lynch & Elizabeth N. Cassano
Cooperative Institute for Research in the Environmental Sciences
University of Colorado, Boulder
Leanne Lestak
Science Writing Mentor:
Nancy Dawson
Significant Opportunities in Atmospheric Research and Science
SOARS Staff & Protégés