Surface Currents from Diagnostic Model
Will Help Track Marine Debris
Nikolai Maximenko and Jan Hafner
The nearly 15,000 drifters in the World Ocean represent standardized 'scientific' marine debris that is tracked with
satellites. Using satellite observations of sea level anomalies and vector winds, a model, the Surface CUrrent Diagnosis
(SCUD) model, has been developed that estimates near-surface currents based on trajectories of Lagrangian drifters.
The SCUD model can tell where a drifter released at a given time and location will go within a certain time. The
movements of different kinds of floating objects under the same ocean currents and wind conditions depend on the
object's geometry (generally, on its vertical extent). After studying the dynamics of other tracers relative to drifters,
the SCUD model can be adjusted to reproduce the surface motions of marine debris, such as plastic pellets, derelict
fishing gear, oil spills, and so on, and help in locating such debris in the vast ocean.
The figure shows the streamlines of the Surface CUrrent Diagnostic velocity on August 20, 2008. Colors indicate speed
and units are cm/s. Dataset is public and distributed through the Asia-Pacific Data-Research Center of the IPRC.