Articles | Volume 11, issue 1
Nat. Hazards Earth Syst. Sci., 11, 127–134, 2011

Special issue: Extreme and rogue waves

Nat. Hazards Earth Syst. Sci., 11, 127–134, 2011

Research article 11 Jan 2011

Research article | 11 Jan 2011

The scenario of a single freak wave appearance in deep water – dispersive focusing mechanism framework

E. Pelinovsky1,2, E. Shurgalina1,2, and N. Chaikovskaya2 E. Pelinovsky et al.
  • 1Department of Nonlinear Geophysical Processes, Institute of Applied Physics, Nizhny Novgorod, Russia
  • 2Nizhny Novgorod State Technical University, Nizhny Novgorod, Russia

Abstract. One of the possible mechanisms of the emergence of freak waves in deep water, based on the dispersive focusing of unidirectional wave packets is analysed. This mechanism is associated with the frequency dispersion of water waves and manifested in the interference of many spectral components, moving with different velocities. Formation of a single freak wave in a random wind wave field is considered in the frame of linear theory. The characteristic lifetime of an abnormal wave in the framework of this mechanism for typical conditions is approximately two minutes, thus, a rapid effect is difficult to predict and prepare for. A rogue wave quickly changes its shape from a high ridge to a deep depression.

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