Jan Hafner

International Pacific Research Center,

School of Ocean Science and Technology,

University of Hawaii

jhafner@hawaii.edu

Diagnostic surface currents SCUD and application to marine debris

The  SCUD model (Surface CUrrents from a Diagnostic model, Maximenko and Hafner, 2010) is used to assess the problem of marine debris and its distribution in the world oceans.

The SCUD is a simple diagnostic model that utilizes AVISO satellite altimetry to determine geostrophic current component, and QuikSCAT ocean surface wind data  to calculate the wind-driven Ekman component.   The maps of total  currents are produced daily on  ¼ degree latitude/longitude grid starting in August 1999 to November 2009, the time span of QuikSCAT data.   The parameters of the SCUD model were determined to match closely the trajectories of surface drifters obtained from the Global Drifter Program.

The  SCUD model and  numerical modeling experimentation are employed to investigate the global distribution of marine debris and its pathways.   As the first experiment over 476,000 particles were released and advected by SCUD model currents. Initially the particles were evenly distributed on  ¼ degree latitude/longitude SCUD model grid.   Over 10 years of numerical integration reveals the formation of 5 major convergence zones, which is consistent with modeling results of  Maximenko et al. 2011.   The  evolution and spatial distribution of tracers will be discussed at the workshop.