| dc.description.abstract | The Great Pacific Garbage Patch (GPGP) is known for accumulating floating plastic, but
little is known on the dominating mechanisms that form its heterogeneity. Submesoscale
processes are likely the main drivers of such heterogeneity, especially if their effect on transport
is object-specific. This hypothesis is investigated by analysing shipboard remote sensing
and metocean data. By developing a Particle Tracking Velocimetry (PTV) methodology,
floating plastic’s velocities are derived from GoPro and drone data collected during The Ocean
Cleanup’s operational and research campaigns. Research findings show that surface currents,
without additional forcings, cannot fully account for more than half of the variance in floating
plastic transport within the North-West region of the GPGP. This suggests that leeway, an
important factor in floating plastic transport, is likely a non-negligible component for most
items in the area, with varying leeway rates observed across the sample. Furthermore, an
analysis on submesoscale accumulation indicates that density fronts may contribute to creating
heterogeneity at smaller scales. Notably, two episodes demonstrate higher floating plastic
accumulation along density fronts than in the surrounding environment. In summary, this
study sheds light on the crucial role of submesoscale processes in shaping the heterogeneity of
the Great Pacific Garbage Patch. Understanding these mechanisms can lead to more effective
strategies for mitigating plastic pollution and its environmental impacts. | |
