Freak Waves and Wave Breaking -Catastrophic Events in Ocean V.E. Zakharov [1,2,3,4] in collaboration with Alexander Dyachenko [3,4], Andrey Pushkarev [2,4],Alexander Prokofiev [3,4] and Alexander Korotkevich [1,3] • University of Arizona • Lebedev Institute for Physics • Landau Institute for Theoretical Physics • Waves and Solitons LLC, W. Sereno Dr., Gilbert, AZ, 85233, USA
Let elevation of ocean surface. In the first approximation this is quasi-stationary, quasi homogeneous random process, close to Gaussian.
Freak waves (major catastrophic event) • Wave breaking (minor catastrophic event) Freak waves are responsible for ship-wreaking, loss of boats, cargo and lives. Wave breaking is the most important mechanism of wave energy dissipation and for transport of momentum from wind to ocean. There are two types of rare catastrophic events on the ocean surface: Analytic theory is for both of these are not developed
“New Year” wave – 1995 year Extreme wave in the Black sea – 2002 year
Freak waves – program for future. We are planning to perform massive numerical simulation of different stationary wave spectra to determine dependence of probability of freak wave formation on energy spectrum. Measuring of energy spectrum is a relatively easy problem. It will Make possible to estimate a danger of freak wave appearance in a given place in a given time…
Wave breaking Evolution of the surface waves spectra is described by the Hasselmann kinetic equation Here nothing but the standart quantum kinetics equation for Boson-type Quasiparticles in the limit of large occupation numbers. - nothing but the standart quantum kinetics equation for Boson-type quasiparticles in the limit of large occupation numbers. - dissipation due to wave breaking. we should have an adequate theory of atmospheric boundary layer To find over ocean. This boundary layer is badly turbulent.
we need the theory of wave breaking. It is not developed yet. To find But we can perform a numerical experiment should be the same in both equations. The instability growth rate was
Magnified surface shape Y(x) for time t=2994 (start of run-off)
Surface shape Y(x) for time t=2994 Similar scale for both axes
Approximation of function: (numerical values obtained by least squares method)
Program Development of these experiments will make possible to determine in a reliable way and improve essentially quality of wave-forecasting models. Then from comparison with experimental data we will be able to estimate which model of is closer to reality.