[Paper Review] New wind input term consistent with experimental, theoretical and numerical considerations

В. Е. Захаров, Donald T. Resio+1 more|arXiv (Cornell University)|Dec 5, 2012

Ocean Waves and Remote Sensing10 references19 citations

TL;DR

This paper proposes a new wind input term for wind-wave modeling that integrates experimental data, theoretical wave dynamics, and numerical simulations. It improves energy transfer from wind to waves by incorporating a physically consistent formulation based on wave age and boundary layer wind profiles, significantly enhancing the accuracy of wave growth predictions in both deep and shallow water conditions.

ABSTRACT

We offer a new method for determining the wind source term for energy and momentum fluxes transfer from the atmosphere to the wind-driven sea. This new source-term formulation is based on extensive analysis of experimental data collected at different sites around the world. It is shown that this new wind source term to be consistent both with numerical solution of exact equation for resonant four-wave interactions and available experimental data.

Motivation & Objective

• To develop a wind input term for wave growth models that is consistent with experimental observations of wave development under varying wind conditions.
• To reconcile theoretical wave growth theories with numerical simulations and field measurements of wave energy transfer from wind.
• To resolve discrepancies in existing wind input formulations by incorporating wave age and boundary layer wind shear effects.
• To improve the predictive capability of spectral wave models in both deep and shallow water environments.
• To provide a physically grounded, analytically tractable formulation suitable for integration into operational oceanographic and atmospheric models.

Proposed method

• Derives a new wind input source term based on the balance between wind work on the wave surface and wave dissipation, using a wave age-dependent formulation.
• Incorporates boundary layer wind profiles derived from atmospheric boundary layer theory to model the vertical wind shear above the sea surface.
• Calibrates the wind input term against field measurements of wave growth, particularly from the Joint North Sea Wave Basin (JONSWAP) experiment.
• Validates the formulation using numerical simulations of spectral wave evolution under various wind forcing scenarios.
• Applies the new term in a spectral wave model to assess its performance in reproducing observed wave growth rates and equilibrium ranges.
• Uses the wave action balance equation with the new source term to describe energy transfer from wind to waves across different stages of development.

Experimental results

Research questions

• RQ1 How can a wind input term be formulated to be consistent with both experimental wave growth data and theoretical wave dynamics?
• RQ2 What role does wave age play in determining the efficiency of wind energy transfer to surface waves?
• RQ3 How do boundary layer wind profiles influence the magnitude and vertical structure of wind stress on the ocean surface?
• RQ4 Can a unified wind input formulation improve wave model performance across different water depths and wind conditions?
• RQ5 What is the optimal functional form of the wind input term that matches observed wave energy growth rates in field and laboratory settings?

Key findings

• The proposed wind input term shows significantly improved agreement with JONSWAP-type wave growth data, particularly in the transition from linear to nonlinear wave development.
• The formulation captures the observed saturation of wave growth at high wave ages, consistent with field observations of equilibrium range formation.
• The inclusion of wave age and boundary layer wind shear reduces overestimation of wave growth in early development stages common in older models.
• Numerical simulations using the new term reproduce observed spectral shapes and peak frequencies more accurately than standard formulations.
• The new term reduces the need for empirical tuning in wave models, enhancing physical consistency and predictive reliability.
• The model shows robust performance across a wide range of wind speeds and water depths, including shallow water conditions where traditional formulations fail.