International Journal of Marine Science, 2024, Vol.14, No.4, 245-255 http://www.aquapublisher.com/index.php/ijms 246 2 Overview of Ocean Waves and Atmospheric Boundary Layer Dynamics 2.1 Characteristics of ocean waves Ocean waves are surface waves generated primarily by wind forces acting on the sea surface. These waves can vary significantly in their characteristics, including wavelength, frequency, and amplitude. Infragravity waves, for instance, are a type of ocean wave with frequencies below those of wind-generated short waves, typically below 0.04 Hz. These waves are generated by mechanisms such as the modulation of wave breaking locations and the merging of bores within the surf zone (Bertin et al., 2018). Near-inertial waves (NIWs) are another type of ocean wave that appear nearly everywhere in the ocean, generated by wind, nonlinear interactions, and other mechanisms. NIWs can propagate over long distances and contribute to turbulent mixing due to their high shear (Alford et al., 2016). 2.2 Structure and dynamics of the atmospheric boundary layer The Atmospheric Boundary Layer (ABL) is the lowest part of the atmosphere, directly influenced by its contact with the Earth's surface. The structure and dynamics of the ABL are complex and can be significantly affected by surface conditions, including the presence of ocean waves. The ABL is characterized by turbulent flows, which are influenced by factors such as surface roughness and thermal stratification. In stable conditions, the ABL can exhibit intermittent turbulence and wave-like motions, which are challenging to model accurately (Sun et al., 2015). The Marine Atmospheric Boundary Layer (MABL) is a specific type of ABL influenced by the ocean surface, where interactions between wind and waves can lead to deviations from the Monin-Obukhov similarity theory, especially under swell conditions (Liu et al., 2022). 2.3 Interaction between ocean waves and ABL The interaction between ocean waves and the ABL is a critical area of study, as it influences weather patterns, climate models, and marine operations. Ocean waves can alter the surface roughness, affecting wind velocity and stress variance in the ABL. For example, the presence of nonlinear internal ocean waves can drive wind velocity and stress variance, setting up localized shear that enhances air-sea momentum flux (Ortiz-Suslow et al., 2019). Coupled ocean-wave-atmosphere models have shown that wave-induced processes, such as wave breaking and Stokes drift, significantly influence coastal areas by enhancing upper ocean mixing and reducing sea surface temperatures (Wu et al., 2019). These interactions are essential for understanding and predicting the dynamics of the ABL over the ocean, as they can lead to complex feedback mechanisms that affect both atmospheric and oceanic processes. 3 Mechanisms of Interaction 3.1 Wave-induced stress on the ABL 3.1.1 Momentum transfer mechanisms The interaction between ocean waves and the atmospheric boundary layer (ABL) involves complex momentum transfer mechanisms. Surface waves introduce a wave-induced component to the total stress, which significantly alters the momentum flux between the ocean and the atmosphere. This wave-induced stress is influenced by factors such as wave growth, decay rates, and the directional wave spectrum (Song et al., 2015). The presence of internal ocean waves can also drive wind velocity and stress variance, enhancing the air-sea momentum flux over wave packets (Ortiz-Suslow et al., 2019). Langmuir circulations, which are wind-induced shear and surface wave interactions, contribute to the modulation of bathymetric stress and turbulence in coastal zones. 3.1.2 Impact on wind profiles Surface waves have a considerable impact on the near-surface mean wind profile and the turbulence structure of the marine ABL. The wave-modified Ekman model demonstrates that surface waves can qualitatively change the structure of the ABL, affecting wind profiles significantly. Observations and simulations show that the mean wind profile and wave-induced stress components are enhanced at the height of wave crests, indicating the influence of intermittent airflow separation events (Husain et al., 2019). The presence of ocean spray, particularly at high wind speeds, can modify the wind profiles by increasing turbulent stress in the sea-spray generation layer.
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