VE_Imperial College_Stereowaves (DTA.AD001.390)

Thematic area

Earth system science and environmental technologies

Project area

Structure responsible for the research project

Marine science institute (ISMAR)

Project manager

ALVISE BENETAZZO
Phone number: +39 041 2407952
Email: alvise.benetazzo@ve.ismar.cnr.it

Abstract

Despite their importance, much has still to be learned about individual oceanic breaking waves. While laboratory studies are often performed on individual breaking waves, ocean-based observations typically integrate information across populations of breaking waves, often not explicitly resolving key properties of individual breaking waves. This is, in part, due to the challenging nature of observing breaking waves at the ocean because (i) they are intermittent in time and space, (ii) they occur at the ocean surface in severe sea states when it is difficult to deploy oceanographic equipment, and (iii) they produce highly turbulent and aerated flows that pose unique measurement challenges. Consequently, photographic-based remote sensing has been used to study ocean breaking waves for decades. However, current approaches are limited because they are unable to estimate the energy dissipation associated with individual breaking waves, a fundamental quantity linked to the severity of breaking, air entrainment and bubble plume penetration depth.

Goals

The overarching goal of this project is to develop new statistical descriptions of whitecap properties in order to better understand variability in breaking wave energy dissipation, whitecap fraction and air entrainment rates. These new datasets will then be leveraged to develop improved air-sea flux parameterisations of gas transfer velocity and SSA particle production flux that are not only functions of wind speed but that can be forced by numerical wave models that include the effects of sea state and wave development. This overarching goal will be achieved by completing the following primary objectives. O1. Acquisition of a large dataset of whitecap images from the AAT. Automated image processing routines will be developed to provide new statistical distributions of individual whitecap properties derived from measuring the temporal evolution of foam area associated with individual whitecaps. O2. Calculation of individual whitecap energy dissipation distributions. The data from O1 will be used with the volume-time-integral method to produce distributions energy dissipation related to individual breaking waves.

Start date of activity

01/12/2020

Keywords

Wind waves, stereo imaging, air-sea interaction

Last update: 02/05/2024