Study Identifies Ocean Processes That Drive Surface Material Clustering
October 20, 2016
Scientists analyzed Gulf of Mexico model simulations to understand the flow processes that drive clustering of buoyant material such as Sargassum, oil from seeps and spills, and debris on the ocean surface. They observed similar clustering patterns from the deep ocean and continental shelf, though the processes driving clustering differed between areas. Smaller-scale ocean features prompted stronger surface divergence and were the dominate driver of initial material clustering. As the effect of small-scale features on clustering diminished over time, larger-scale processes drove continued clustering. Understanding how different ocean processes determine the way materials accumulate on the surface can improve the effectiveness of oil spill cleanup efforts. The researchers published their findings in Journal of Geophysical Research: Oceans: Ocean processes underlying surface clustering.
Lagrangian divergence is the major force that contributes to clustering of material at the ocean surface. This study examined the effects of various surface ocean processes on Lagrangian divergence using data from the Grand Lagrangian Deployment or GLAD (deep ocean surface water) and the Surfzone Coastal Oil Pathways Experiment or SCOPE (continental shelf surface water). The team focused on surface clustering influenced by submesoscale to mesoscale ocean features (500 m to 500 km horizontal scales). These small- and large-scale processes control cluster formation, deformation, and dispersal. The scientists conducted a series of numerical ocean model simulations with increasing resolutions – each of which captured a different spectrum of phenomena – to systematically investigate ocean processes.