Research Hints at How Marine Debris Accumulates in the Ocean
AOML oceanographer Rick Lumpkin, along with researchers from the University of Miami's Rosenstiel School, have developed a model that simulates the trajectory of floating marine debris at the ocean surface. The team compared the model's simulated results against a 20+ year database of satellite-tracked surface drifting buoys from NOAA's Global Drifter Program.* They found that undrogued or unanchored (i.e., with lost sea anchor) buoys accumulated in the world's five oceanic subtropical gyres in much the same manner as plastic debris, shedding light on how floatsam accumulates into massive garbage patches in the ocean. The speed at which the undrogued buoys accumulated in the gyres precluded attributing the effect to winddriven currents alone. Instead, the study atrributes the accumulation to finite-size and buoyancy (i.e., inertial) effects on the motion of the undrogued drifters exposed to ocean currents and wind drags. The authors infer marine plastic debris and flotsam are similarly impacted.
Researchers found that undrogued (i.e., unanchored) satellite-tracked drifting buoys accumulated in the world's five oceanic subtropical gyres (orange and red tones) in much the same manner as plastic debris.
*Beron-Vera, F.J., M.J. Olascoaga, and R. Lumpkin, 2016: Inertia-induced accumulation of flotsam in the subtropical gyres. Geophysical Research Letters, 43(23):12,228-12,233, doi:10.1002/2016GL071443.