2016/01/20 by Tobias Kukulka, Kara L. Law, Kara Lavender Law +2 · 51 citations
Chemistry · Engineering · Environmental Science · #Atmospheric sciences #Chemistry #Diurnal cycle #Environmental science #Geology #Langmuir #Langmuir Turbulence #Layer (electronics) #Marine Biology and Environmental Chemistry #Materials science #Mechanics #Microplastics and Plastic Pollution #Mixing (physics) #Oceanography #Physics #Surface layer #Turbulence #Water Quality Monitoring Technologies
paper · doi:10.1175/jpo-d-15-0242.1
published in Journal of Physical Oceanography 46(3), 809-815 (American Meteorological Society)
openalex publication_date 2016/01/20 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/31
Abstract Buoyant microplastic marine debris (MPMD) is a pollutant in the ocean surface boundary layer (OSBL) that is submerged by wave-driven turbulent transport processes. This study analyzes observed MPMD surface concentrations in the Atlantic and Pacific Oceans to reveal a significant increase in concentrations during surface heating and a decrease during surface cooling. Turbulence-resolving large-eddy simulations of the OSBL for an idealized diurnal heating cycle suggest that turbulent downward fluxes of buoyant tracers are enhanced at night, facilitating deep submergence of plastics, and suppressed in heating conditions, resulting in surface-trapped MPMD. Simulations agree better with observations if enhanced mixing due to wave-driven Langmuir turbulence (LT) is included. The simulated time-dependent OSBL response results in hysteresis effects so that surface concentrations depend also on the phase of the diurnal heating cycle. The results demonstrate the controlling influence of surface heat fluxes and LT on turbulent transport in the OSBL and on vertical distributions of buoyant marine particles.