TITLE:
Sufficient noise and turbulence can induce phytoplankton patchiness
AUTHORS:
Hiroshi Serizawa, Takashi Amemiya, Kiminori Itoh
KEYWORDS:
Eddy; Fluctuation; Noise; Patchiness; Reaction-Advection-Diffusion Model; Turbulence
JOURNAL NAME:
Natural Science,
Vol.2 No.4,
May
7,
2010
ABSTRACT: Phytoplankton patchiness ubiquitously obser- ved in marine ecosystems is a simple phy- sical phenomenon. Only two factors are required for its formation: one is persistent variations of inhomogeneous distributions in the phytopl- ankton population and the other is turbulent stirring by eddies. It is not necessary to assume continuous oscillations such as limit cycles for realization of the first factor. Instead, a certain amount of noise is enough. Random fluctua-tions by environmental noise and turbulent ad-vection by eddies seem to be common in open oceans. Based on these hypotheses, we pro-pose seemingly the simplest method to simulate patchiness formation that can create realistic images. Sufficient noise and turbulence can induce patchiness formation even though the system lies on the stable equilibrium conditions. We tentatively adopt the two-component model with nutrients and phytoplankton, however, the choice of the mathematical model is not essen-tial. The simulation method proposed in this study can be applied to whatever model with stable equilibrium states including one-com-ponent ones.