Fabio Addona

University of Delaware | UDel UD · School of Marine Science and Policy

It is known that long waves (or swell) ruffled by an opposing wind tends to be dissipated, while shorter waves develop on top of them and travel in the wind direction. However, the long waves are mostly considered progressive and the effect of reflection is neglected. We present an experiment study of mechanically generated regular waves in partial...

When the surface wave field is in local equilibrium with wind forcing, the air-sea transfer coefficients can be expressed as a function of a reference wind speed only. However, such conditions are generally not present in the ocean and exchanges of mass, momentum, gasses, etc., at the air-water interface are strongly influenced by sea state conditi...

Coastal monitoring is strategic for the correct assessment of nearshore morphodynamics, to verify the effects of anthropogenic interventions for the purpose of coastal protection and for the rapid assessment of flooding vulnerability due to severe events. Remote sensing and field surveys are among the main approaches that have been developed to mee...

The Italian coastline stretches over about 8350 km, with 3600 km of beaches, representing a significant resource for the country. Natural processes and anthropic interventions keep threatening its morphology, moulding its shape and triggering soil erosion phenomena. Thus, many scholars have been focusing their work on investigating and monitoring s...

In fluid mechanics, fountains take place when a source fluid is driven by its own momentum into a surrounding ambient fluid and it is counterbalanced by buoyancy. These phenomena are largely encountered in nature and human activities. Despite the numerous studies on the subject, few experimental data are available about the internal structure of tu...

The air-water interaction has been long studied in ocean physics, due to its importance to natural hazard and impact on human activities. Several studies in the literature provided advancements for a better comprehension of gases, mass and momentum exchanges at the interface. However, the subject is wide and many aspects are still unsolved, especia...

The use of video-monitoring techniques is significantly increased due to the diffusion of high-resolution cameras at relatively low-costs and they are largely used to estimate the shoreline evolution and wave run-up, as important coastal state indicators to be monitored and predicted for the assessment of flooding and erosion risks. In this work, w...

Air-sea interaction is a relevant topic with still many open questions, also in consideration of the numerous and complex scenarios that occur in nature. In this manuscript we report an experimental study of partially-reflected regular (long) waves under the action of an opposite wind, which generates short wind-waves (wind generated water waves, W...

We present the experimental analysis of the interaction between wind waves and currents, during the generation process, through laboratory experiments in a wind-waves-current tunnel. The objective is the quantification of the effects of a co-/counter-current on the main characteristics and statistical estimators of the wave field. Twenty-two experi...

In recent years, the use of video-monitoring techniques for the evaluation of coastal erosion in maritime areas is significantly increased, due to the diffusion of high-resolution cameras at relatively-low cost (Archetti et al., 2016). The capability of performing several analyses makes video monitoring suitable for applications in coastal research...

The main aim of this thesis is to shed light about the influence that partial reflection (one of the most common cases encountered both in field and laboratory studies of water waves) exerts on a wave field where regular waves are present alone and under the action of following or opposing wind. We have analyzed experimentally and theoretically the...

We study experimentally the effects of different reflective conditions on momentum transfer in water waves. A theoretical model is also derived considering the reflection coefficient and the phase shift. The theoretical model is applied to quantify the spatial variation of velocity covariance and mean water level. Wave shear stress, mean water leve...

KEY POINTS The interaction between wind generated waves and co/counter-currents in laboratory conditions are discussed. As expected, the growth of the wave height with the counter-currents is significantly limited by the wave breaking. The wave steepness decreases for increasing average velocity of the co/counter-current. Waves appear in group a...

Wind-waves play a relevant role in the downward flux of mass, momentum and heat, and in their balances. Thus, they are quite significant in small-and large-scale processes like global warming, especially in continental shelf. There is still no consensus on the effectiveness of different mechanisms in enhancing, e.g., the carbon dioxide (CO2) uptake...

We present theoretical and experimental analyses of the critical condition where the regime is preserved inertial-buoyancy or viscous-buoyancy in uniform-density gravity current (which propagates over a horizontal plane) of variable volume V = qt δ in a power-law cross-section (width described by f (z) = bz α , where z is the vertical coordinate),...

Resumen En este trabajo se presentan los resultados preliminares de una serie de ensayos realizados en el Canal de Interacción Atmósfera-Océano (CIAO) del Instituto Interuniversitario de Investigación del Sistema Tierra en Andalucía. Se realizaron ensayos para analizar la influencia del viento en el transporte de cantidad de movimiento y en las com...

We present an experimental investigation, supported by a theoretical model, of the motion of lock-release, constant inflow, and time varying inflow gravity currents (GCs) into a linearly stratified ambient fluid at large Reynolds number. The aim is the experimental validation of a simple model able to predict the slumping phase front speed and the...

KEY POINTS:  The present work aims to study the behavior of a dense fluid current in a rectangular (or in a circular) cross-section channel. The denser fluid propagates into a less dense ambient fluid, with linear stratification of density in the vertical  A simplified model was used to compute the front speed of the gravity current. The theoreti...

We investigate high-Reynolds number gravity currents (GC) in a horizontal channel of circular cross-section. We focus on GC sustained by constant or time varying inflow (volume of injected fluid $\propto\;t^{\alpha}$, with $\alpha=1$ and $\alpha>1$). The novelty of our work is in the type of the gravity currents: produced by influx/outflux boundary...