Details

Autor(en) / Beteiligte

• Pushkarev, Andrei

Titel

Laser-like wave amplification in straits

Ist Teil von

• Ocean dynamics, 2021-02, Vol.71 (2), p.195-215

Ort / Verlag

Berlin/Heidelberg: Springer Berlin Heidelberg

Erscheinungsjahr

2021

Link zum Volltext

Quelle

SpringerLink Journals - AutoHoldings

Beschreibungen/Notizen

• We present research on the excitation of ocean surface wind waves in non-homogeneous situations, for the case of a deep water strait in the presence of a constant wind, blowing perpendicular to the coast line. The statistical wave model used is based on the Hasselmann equation with high-wavenumbers wave-breaking dissipation, exact non-linear four-wave interaction, and ZRP (Zakharov-Resio-Pushkarev (Zakharov et al. Nonlin Process Geophys 24:581–597 2017 ) wind input term. At the first stage, the waves propagate in the wind direction in a step-like moving front manner, which is the combination of self-similar fetch-limited and duration-limited solutions of the Hasselmann equation. The second stage begins after intermediate self-similar linear asymptotics for wave energy is built along the fetch. Beginning with that time, the wave groups, propagating across and against the wind due to nonlinear interaction, are observed. Despite the absence of long-wave dissipation, the system asymptotically evolves into a complex quasi-stationary state, comprised of the self-similar “wind sea” in the wind direction, and quasi-monochromatic waves, radiating close to orthogonally with respect to the wind, while slightly tilting from perfectly orthogonal to the wind direction, with the angle slant increasing toward the wave turbulence origination shore line, and reaching 15 ∘ close to it. The total wave energy in the asymptotic state exceeds the wave sea energy propagating along the wind by a factor of two due to the presence of quasi-orthogonal and counter the wind wave fields. Very similar turbulence structure was previously observed experimentally; this paper presents a theoretical explanation of these results.