A Monte Carlo Method for Projecting Uncertainty in 2D Lagrangian Trajectories
Abstract
In this study, a novel method is proposed for modeling the propagation of uncertainty due to subgrid-scale processes through a Lagrangian trajectory advected by ocean surface velocities. The primary motivation and application is differentiating between active and passive trajectories for sea turtles as observed through satellite telemetry. A spatiotemporal launch box is centered on the time and place of actual launch and populated with launch points. Synthetic drifters are launched at each of these locations, adding, at each time step along the trajectory, Monte Carlo perturbations in velocity scaled to the natural variability of the velocity field. The resulting trajectory cloud provides a dynamically evolving density field of synthetic drifter locations that represent the projection of subgrid-scale uncertainty out in time. Subsequently, by relaunching synthetic drifters at points along the trajectory, plots are generated in a daisy chain configuration of the “most likely passive pathways” for the drifter.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2009
- Bibcode:
- 2009AGUFMOS51A1084R
- Keywords:
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- 4263 OCEANOGRAPHY: GENERAL / Ocean predictability and prediction;
- 4294 OCEANOGRAPHY: GENERAL / Instruments and techniques;
- 4568 OCEANOGRAPHY: PHYSICAL / Turbulence;
- diffusion;
- and mixing processes;
- 4599 OCEANOGRAPHY: PHYSICAL / General or miscellaneous