Articles | Volume 18, issue 6
Nonlin. Processes Geophys., 18, 1001–1012, 2011
Nonlin. Processes Geophys., 18, 1001–1012, 2011

Research article 21 Dec 2011

Research article | 21 Dec 2011

The effect of stochastic perturbations on plankton transport by internal solitary waves

M. Stastna1, F. J. Poulin1, C. Subich1, and J. V. Mecking2 M. Stastna et al.
  • 1Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario, N2L 3G1, Canada
  • 2IFM-GEOMAR, Leibniz-Institut für Meereswissenschaften, Düsternbrooker Weg 20, 24105, Kiel, Germany

Abstract. Internal solitary and solitary-like waves are a commonly observed feature of density stratified natural waters, including lakes and the coastal ocean. Since such waves induce significant currents throughout the water column they can be responsible for significant transport of both passive and swimming biota. We consider simple models of moving zooplankton based on the Langevin equation. The small amplitude randomness significantly alters the nature of particle motion. In particular, passage through the wave leads to strongly non Gaussian particle distributions. When the plankton swims to return to its equilibrium photic level, a steady state that balances randomness, swimming and wave-induced motions is possible. We discuss possible implications of this steady state for organisms that feed on plankton.