Extreme Wave Climate
                           Characterization, Forecast, and Warning
        The Apostle Islands lakeshore in Lake Superior is a world-class destination for sea kayaking, luring paddlers with scenic wilderness, ancient geology and a rich cultural history. Some of the most popular attractions are the sea caves located at several spots around the archipelago. The water environment in the Apostle Islands is undoubtedly quite complex and dynamic due to the interactions of winds, currents, and the surrounding 22 islands at the site. Waves generated in Lake Superior can diffract and reflect when they encounter the islands and may combine to form extreme waves in a process known as geometric focusing. This process is applied to determine local regions of energetic wave fields for use in wave power generation around the world. In addition, significant energy and momentum transfers can occur during the wave and current interaction, yielding extreme waves that can affect the navigation and kayakers' safety. To date information of wave climate in Lake Superior is very little. Currently we are developing an in-situ Real-Time Wave Observation System (RTWOS) that can be accessed through any portable wireless device. Furthermore a real-time INFOS-Apostle is currently developed to provide real-time wave climate in the Apostle Islands. Outreach efforts (see Wisconsin State Journal Article has been continuously paid to address the community and society needs. An energy efficient push button Real-Time Wave Kiosk System (RTWKS) with a safety index for kayakers is also designed, built, and installed at the Meyers Beach, WI, where most kayakers/boaters enter water in Lake Superior. A new observation network, Water Information for a Safe Coast WISC-Watch, for the Apostle Islands is implemented. The benefit of providing certain conditions in favor of the occurrence of dangerous extreme waves/freak waves is critical for the warning kayakers and boaters in Great Lakes.

  Apostle Islands in Lake Superior                                                  Real-time wave buoy and nowcast/forecast modeling                                  15 feet extreme wave  


  • Anderson, J.D. and Wu, C.H., Development and Application of a real-time water environment cyber-infrastructure for kayaker safety in the Apostle Islands, Lake Superior, Lake Superior. J. of Great Lakes Research, 44(5), 990-1001, doi.org/10.1016/j.jglr.2018.07.006, 2018
  • Anderson, J.D., Wu, C.H., and Schwab, D.J., Wave climatology in the Apostle Islands, Lake Superior, J. Geophysical Research-Oceans, 120(7), 4869-4890, 2015.
  • Young C.C. and Wu, C.H., A σ - coordinate non-hydrostatic model with embedded Boussinesq-type like equations for modeling deep-water waves, International J. for Numerical Methods in Fluids, 63(12),1448-1470, 2010.
  • Wu, C.H., Young, C.C., Chen, Q.J., and Lynett, P.J., Efficient non-hydrostatic modeling of nonlinear waves from shallow to deep waters, J. of Waterway, Port, Coastal, and Ocean Engineering - ASCE, 136(2), 104-118, 2010.
  • Young, C.C. and Wu, C.H., Non-hydrostatic modeling of nonlinear deep-water wave groups, J. of Engineering Mechanics-ASCE, 136(2), 155-167, 2010.
  • Young, C.C. and Wu, C.H., An efficient and accurate non-hydrostatic model with embedded Boussinesq-type like equations for surface wave modeling, International J. for Numerical Methods in Fluids, 60(1), 27-53, 2009.
  • Young, C.C., Wu, C.H., Kuo, J.T., and Liu, W.C., A higher-order sigma-coordinate non-hydrostatic model for nonlinear surface waves, Ocean Engineering, 34(10), 1357-1370, 2007.
  • Yao, A. and Wu, C.H., Spatial and temporal characteristics of transient extreme waves on depth-varying currents, J. of Engineering Mechanics-ASCE, 132 (9), 1015-1025, 2006.
  • Choi, D.Y. and Wu, C.H., A new efficient 3D non-hydrostatic free-surface flow model for simulating water wave motions, Ocean Engineering, 33(5-6), 587-609, 2006.
  • Yuan, H.L. and Wu, C.H., Fully non-hydrostatic modeling of surface waves,  J. of Engineering Mechanics-ASCE, 132 (4), 447-456, 2006.
  • Wanek, J. and Wu, C.H., Automated trinocular stereo imaging system for three-dimensional surface wave measurements, Ocean Engineering, 33(5-6), 723-747, 2006.  (see breaking wave evolution here)
  • Yao, A. and Wu, C.H., Incipient breaking of unsteady waves on sheared currents, Physics of Fluids, 17, 082104, 2005.
  • Yao, A. and Wu, C.H., An automated image-based technique for tracking surface wave profiles, Ocean Engineering, 32(2) 157-173, 2005.
  • Yao, A. and Wu, C.H., Energy dissipation of unsteady wave breaking on currents, J. Physical Oceanography, 34, N10, 2288-2304, 2004.
  • Wu, C.H., Yao, A., and Chang, K.A., DPIV measurements of unsteady deep-water wave breaking on following currents, "PIV and Modeling Water Wave Phenomena, World Scientific Publication Co., Advances in Coastal and Ocean Engineering - Vol. 9, 2004.
  • Wu, C.H., Nepf, H.M., Cowen, E.A., Surface current and vorticity generated by three-dimensional breaking waves, accepted under revision J. Fluid Mech., 2004.
  • Wu, C.H. and Nepf, H. M, Breaking wave criteria and energy losses for three-dimensional breaking waves, C10, 3177, 10.1029 2001JC001077, 41-1-18, J. Geophysical Research-Oceans, 2002.
  • Nepf, H.M., Wu, C.H., Chan, E.S., A comparison of two- and three-dimensional wave breaking, J. Physical Oceanography, 28, N7, 1496-1510, 1998
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