Wave-Induced Wind in the Marine Boundary Layer

Abstract

Preface This techrical report describes research by Dr. Cardone that began in 1 966 and has been sponsored by three different contracts as its scope increased and as the many applications that it will have become apparent. The first application of this work is to use available data more intelligently in the development of numerical wave hindcasting and forecasting procedures. In 1964, a wave climatology for the North Atlantic was produced that used ship reports to generate the wind fields for the wave hindcasts. It took one half an hour on a CDC 1604 to generate the wind fields for every six hours for a year. Although the hindcasts gave quite good results, it was clear that higher resolution wind fields and a better theory for the winds in the planetary boundary layer would improve the quality of wave predictions. This report more than adequately makes up for the nalvet of previous wind field models in the planetary boundary layer. A second goal for this study was to aid in the development of the software to be used should radar scatterometry and passive microwave data become available from a spacecraft. The definition of the winds over the ocean depends on many factors. Work is actively in progress to combine the results of this paper with simulated data such as might be obtained from remote .sensing techniques so that an optimum analysis of the planetary boundary layer can be made. This report makes it possible to develop ways to use the widely scattered ship reports over the ocean obtained on a synoptic basis in an intelligent way for the extrapolation and interpolation of spacecraft data into areas not observed by ships. A numerical model of the North Atlantic Ocean is presently under development for the Office of Naval Research. For this model, the wind stress at the sea surface and the sensible and latent heat fluxes at the air sea boundary are needed. The procedures described in this report define the wind stress at the sea surface, the atmospheric stability and the air sea temperature differences on an oceanic scale.

Seasonal Variability of Wind Sea and Swell Waves Climate along the Canary Current: The Local Wind Effect

“…Recent studies have devoted their attention to the qualitative analysis of the wave field, from a wave-climate perspective [5][6][7][8][9][10][11][12] to an air-sea interaction point of view [13][14][15][16][17][18].The reason for this lies mostly in the fact that the air-sea exchanging and interaction processes are sea-state dependent, i.e., the way waves modulate the exchange of momentum, heat, mass, and several other scalars across the air-sea interface is influenced by the prevalence of one type of waves over the other [19,20]. For example, as swell waves propagate into light wind areas they perform work on the overlying atmosphere, inducing a pressure perturbation in the first few meters of the marine atmospheric boundary layer (MABL), producing a forward thrust on the flow [14,17,21,22]].…”

“…For example, as swell waves propagate into light wind areas they perform work on the overlying atmosphere, inducing a pressure perturbation in the first few meters of the marine atmospheric boundary layer (MABL), producing a forward thrust on the flow [14,17,21,22]]. Swell loses energy to the atmosphere as it gradually decays [2,23], accelerating the airflow at lower altitudes, in the form of the so called "wave-driven wind", inducing a departure from the logarithmic wind profile [15,21].…”

“…Swell loses energy to the atmosphere as it gradually decays [2,23], accelerating the airflow at lower altitudes, in the form of the so called "wave-driven wind", inducing a departure from the logarithmic wind profile [15,21]. For this reason swell has a consistent influence on the overall turbulence structure of the boundary layer, since it reduces the wind shear in the MABL and consequently the mechanical production of turbulence [14,15,18,22,23]. Under the wave-growing process, energy is transferred to the ocean throughout vertical transport of horizontal momentum via momentum flux, which drives currents, generates waves, and triggers wave breaking.…”

Projection of Global Wave Climate Change toward the End of the Twenty-First Century

“…Changes in wave climate are therefore of central importance for almost all aspects of coastal and offshore activities. From a scientific perspective, waves represent a key process, in the climate system, modifying the exchange of momentum, heat, and mass across the air-sea interface (e.g., Sullivan et al 2008;Smedman et al 2009;H€ ogstr€ om et al 2009;Semedo et al 2009;Nilsson et al 2012;Cavaleri et al 2012). Changes in wave climate may change the pattern of such fluxes in a long-term perspective, and its study is therefore paramount.…”

A New Platform for the Determination of Air–Sea Fluxes (OCARINA): Overview and First Results

“…However, numerical models have been run (e.g. Sullivan et al, 2008), and wind tunnel data (Grare et al, 2013) as well as theoretical models (Kudryavtsev et al, 2001, Semedo et al, 2009 were already published on the subject. According to the simulations made by Sullivan et al (2008, Page 1231 Figure 5), wind should be in phase with the elevation, i.e.…”