Surface Currents from Diagnostic Model

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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.