1. Physics-informed laboratory estimation of Sargassum windage
- Author
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Olascoaga, M. J., Beron-Vera, F. J., Beyea, R. T., Bonner, G., Castellucci, M., Goni, G. J., Guigand, C., and Putman, N. F.
- Subjects
Physics - Atmospheric and Oceanic Physics - Abstract
A recent Maxey--Riley theory for \sarg raft motion, which models a raft as a network of elastically interacting finite-size, buoyant particles, predicts the carrying flow velocity to be given by the weighted sum of the water and air velocities $(1-\alpha)\mathbf{v} + \alpha \mathbf w$. The theory provides a closed formula for parameter $\alpha$, referred to as \emph{windage}, depending on water-to-particle-density ratio or buoyancy ($\delta$). From a series of laboratory experiments in an air--water stream flume facility under controlled conditions, we estimate $\alpha$ ranging from 0.02 to 0.96\pct. On average, our windage estimates can be up to 9 times smaller than considered in conventional \emph{Sargassum} raft transport modeling, wherein it is customary to add a fraction of $\mathbf w$ to $\mathbf{v}$ chosen in an ad-hoc piecemeal manner. Using the formula provided by the Maxey--Riley theory, we estimate $\delta$ ranging from 1.00 to 1.49. This is consistent with direct $\delta$ measurements, ranging from 0.9 to 1.25, which provide support for our $\alpha$ estimation. more...
- Published
- 2023
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