Articles | Volume 24, issue 2
Nonlin. Processes Geophys., 24, 293–305, 2017
https://doi.org/10.5194/npg-24-293-2017

Special issue: Current perspectives in modelling, monitoring, and predicting...

Nonlin. Processes Geophys., 24, 293–305, 2017
https://doi.org/10.5194/npg-24-293-2017

Research article 29 Jun 2017

Research article | 29 Jun 2017

Modeling the dynamical sinking of biogenic particles in oceanic flow

Pedro Monroy1, Emilio Hernández-García1, Vincent Rossi1,2, and Cristóbal López1 Pedro Monroy et al.
  • 1IFISC, Instituto de Física Interdisciplinar y Sistemas Complejos (CSIC-UIB), 07122 Palma de Mallorca, Spain
  • 2Mediterranean Institute of Oceanography (UM 110, UMR 7294), CNRS, Aix Marseille Univ., Univ. Toulon, IRD, 13288, Marseille, France

Abstract. We study the problem of sinking particles in a realistic oceanic flow, with major energetic structures in the mesoscale, focussing on the range of particle sizes and densities appropriate for marine biogenic particles. Our aim is to evaluate the relevance of theoretical results of finite size particle dynamics in their applications in the oceanographic context. By using a simplified equation of motion of small particles in a mesoscale simulation of the oceanic velocity field, we estimate the influence of physical processes such as the Coriolis force and the inertia of the particles, and we conclude that they represent negligible corrections to the most important terms, which are passive motion with the velocity of the flow, and a constant added vertical velocity due to gravity. Even if within this approximation three-dimensional clustering of particles can not occur, two-dimensional cuts or projections of the evolving three-dimensional density can display inhomogeneities similar to the ones observed in sinking ocean particles.

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Short summary
We study the problem of sinking particles in a realistic oceanic flow, with major energetic structures in the mesoscale, focussing on marine biogenic particles. By using a simplified equation of motion for small particles in a mesoscale velocity field, we estimate the influence of physical processes such as the Coriolis force and the particle's inertia, and we conclude that they represent negligible corrections to passive transport by the flow, with added vertical velocity due to gravity.