Building a Maxey--Riley framework for surface ocean inertial particle dynamics
arXiv:1906.01080 · doi:10.1063/1.5110731
Abstract
A framework for the study of surface ocean inertial particle motion is built from the Maxey--Riley set. A new set is obtained by vertically averaging each term of the original set, adapted to account for Earth's rotation effects, across the extent of a sufficiently small spherical particle that floats at an assumed unperturbed air--sea interface with unsteady nonuniform winds and ocean currents above and below, respectively. The inertial particle velocity is shown to exponentially decay in time to a velocity that lies close to an average of seawater and air velocities, weighted by a function of the seawater-to-particle density ratio. Such a weighted average velocity turns out to fortuitously be of the type commonly discussed in the search-and-rescue literature, which alone cannot explain the observed role of anticyclonic mesoscale eddies as traps for marine debris or the formation of great garbage patches in the subtropical gyres, phenomena dominated by finite-size effects. A heuristic extension of the theory is proposed to describe the motion of nonspherical particles by means of a simple shape factor correction, and recommendations are made for incorporating wave-induced Stokes drift, and allowing for inhomogeneities of the carrying fluid density. The new Maxey--Riley set outperforms an ocean adaptation that ignored wind drag effects and the first reported adaption that attempted to incorporate them.
To appear in Phys. Fluids
References in corpus (5)
- Surface Wave Effects in the NEMO Ocean Model: Forced and Coupled Experiments
- Advances in Search and Rescue at Sea
- Normal form transforms separate slow and fast modes in stochastic dynamical systems
- Addendum to "Coherent Lagrangian vortices: The black holes of turbulence"
- Markov-chain-inspired search for MH370
Cited by in corpus (18)
- The dispersion of spherical droplets in source-sink flows and their relevance to the COVID-19 pandemic
- Clustering of marine-debris- and \emph{Sargassum}-like drifters explained by inertial particle dynamics}
- Observation and quantification of inertial effects on the drift of floating objects at the ocean surface
- Nonlinear dynamics of inertial particles in the ocean: From drifters and floats to marine debris and Sargassum
- Transition paths of marine debris and the stability of the garbage patches
- Carriers of \emph{Sargassum} and mechanism for coastal inundation in the Caribbean Sea
- A minimal Maxey--Riley model for the drift of \emph{Sargassum} rafts
- How winds and ocean currents influence the drift of floating objects
- Dynamical geography and transition paths of Sargassum in the tropical Atlantic
- Stability of the Malvinas Current
- Particle dispersion and clustering in surface ocean turbulence with ageostrophic dynamics
- Physics-informed laboratory estimation of Sargassum windage
- Beaching model for buoyant marine debris in bore-driven swash
- Efficient numerical methods for the Maxey-Riley-Gatignol equations with Basset history term
- The fluid mechanics of poohsticks
- Tracing the origin of tropical North Atlantic Sargassum blooms to West Africa
- Relevance of the Basset history term for Lagrangian particle dynamics
- Bounds to the Basset-Boussinesq force on particle laden stratified flows