Title: Lagrangian stochastic processes for ocean surface drifter trajectories
Joint work with Sofia Olhede (UCL) and Jonathan Lilly and Jeffrey Early (NWRA, Seattle)
Abstract: The oceans plays a pivotal role in the global climate system, and to develop our understanding there is a need to connect physical models of ocean dynamics with vast arrays of data collected from modern sensors. In this talk, I will present a stochastic process model that can describe the motion of Lagrangian ocean surface trajectories obtained from freely drifting satellite-tracked instruments, commonly known as “drifters”. The model builds on existing literature, using more generalised stochastic processes that can capture effects that are oscillatory, spatially anisotropic, and have varying degrees of small-scale roughness or fractal dimension. We use our model to analyse the entire Global Drifter Program database of observations since 1979, constituting over 70 million data points. Our findings uncover interesting spatial patterns and develop general understanding of ocean circulation and ocean surface dynamics.