Interaction of Noise and Nonlinear Dynamics in the Wind-Driven Ocean Circulation

Monday, March 11, 2013 - 3:00pm - 3:30pm
Keller 3-180
Henk Dijkstra (Rijksuniversiteit te Utrecht)
Results will be presented of a study on the interaction of noise and nonlinear dynamics
in a quasi-geostrophic model of the wind-driven ocean circulation. The recently developed
framework of dynamically orthogonal field theory is used to determine the statistics of
the flows which arise through successive bifurcations of the system as the ratio of forcing
to friction is increased. Focus will be on the understanding of the role of the spatial and
temporal coherence of the noise in the wind-stress forcing. For example, when the wind-stress noise
is additive and temporally white, the statistics of the stochastic ocean flow does not depend
on the spatial structure and amplitude of the noise. This implies that a spatially
inhomogeneous noise forcing in the wind stress field only has an effect on the dynamics
of the flow when the noise is temporally colored. The latter kind of stochastic forcing
may cause more complex or more coherent dynamics depending on its spatial correlation
MSC Code: