Modelling of short-term dispersion in the sea surface layer

The relative dispersion of GLAD drifter campaign conducted in the northern Gulf of Mexico is investigated. The high temporal and spatial sampling of the GPS-satellite tracked drifters permits to study the short-term dispersion. The exponential regime of dispersion is detected for different groups of drifter trajectories. Experimental laws of relative horizontal diffusivity are inferred. A variable diffusivity stochastic model of dispersion, using GLAD relative diffusivity experimental laws and NCOM derived surface velocity fields, is developed and used to simulate the initial phase of dispersion of the GLAD campaign.