The Role of Ekman Currents, Geostrophy, and Stokes Drift in the Accumulation of Floating Microplastic ...

Floating microplastic in the oceans is known to accumulate in the subtropical ocean gyres, but unclear is still what causes that accumulation. We investigate the role of various physical processes, such as surface Ekman and geostrophic currents, surface Stokes drift, and mesoscale eddy activity, on...

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Bibliographic Details
Main Authors: Onink, Victor, Wichmann, David, Delandmeter, Philippe, Sebille, Erik
Format: Text
Language:English
Published: AGU 2019
Subjects:
Online Access:https://dx.doi.org/10.7892/boris.131871
https://boris.unibe.ch/131871/
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Summary:Floating microplastic in the oceans is known to accumulate in the subtropical ocean gyres, but unclear is still what causes that accumulation. We investigate the role of various physical processes, such as surface Ekman and geostrophic currents, surface Stokes drift, and mesoscale eddy activity, on the global surface distribution of floating microplastic with Lagrangian particle tracking using GlobCurrent and WaveWatch III reanalysis products. Globally, the locations of microplastic accumulation (accumulation zones) are largely determined by the Ekman currents. Simulations of the North Pacific and North Atlantic show that the locations of the modeled accumulation zones using GlobCurrent Total (Ekman+Geostrophic) currents generally agree with observed microplastic distributions in the North Pacific and with the zonal distribution in the North Atlantic. Geostrophic currents and Stokes drift do not contribute to largeā€scale microplastic accumulation in the subtropics, but Stokes drift leads to increased ...