Island Wakes: The Interaction of Land, Air, and Sea

1
Island Wakes The Interaction of Land, Air, and
Sea

• By Ashley Diggs, Susan Jacob, Samuel Burlacu,
  Francisco Martinez, Shane Gallup
• Upward Bound Math and Science
• SEEMS 2004

2
Introduction

• Island Wake
• Disturbance in wind, clouds, and ocean waves
  caused by flow past an island
• Types of island wakes
• Smooth convergence
• Twin vortices
• Karman Vortices
• Turbulent

3
Karman Vortex Theory

• Drag slows wake causing spin along its edges
• Eddies will scale with obstacle size
• The ratio between cross stream and along stream
  spacing of successive eddies is 28

4
Satellite Background

• Terra and Aqua
• NASA MODIS satellites
• Polar Orbiting
• True color images
• High resolution
• 250 m per pixel
• Swath width gt 1000 km

5
Materials

• MODIS satellite images
• Adobe Photoshop
• Microsoft Excel
• Album of Fluid Mechanics

6
Procedure

• Qualitative Analysis
• Wake type
• Wind field - 3D
• Cloud pattern
• Quantitative Analysis
• Island size
• Vortex positions
• Vortex spacing

7
Qualitative Results

• Fewer clouds in center of vortices
• Clouds on upwind side of vortex pairs
• Downdrafts in center of vortices
• Updrafts upwind of vortex pairs

8
Quantitative Results

• The larger the island, the slower the wake
• Large islands give large vortices
• The ratio between cross stream and along stream
  spacing of successive eddies is 77, not 28

9
Conclusion

• Technological Advancement
• Quantitative data from satellite images
• Allows fieldwork over the oceans
• Societal Importance
• Building location
• Sea travel
• Fishing
• Recreation

10
Acknowledgments

• Our group would like to thank our professors,
  Drs. George Young and Eugene Clothiaux for their
  expertise in meteorology.
• We would also like to thank our UBMS faculty
  member, Dustin Wenner for his guidance and
  assistance.
• Inspiration by Drs. Von Karman and Smith