Biological-Physical Interaction of Particle Distribution: The Turbulent Mixed-Layer Pump and Particle Sinking Explored Through Modeling and Observations
College
College of Sciences
Department
Department of Ocean and Earth Sciences
Graduate Level
Doctoral
Graduate Program/Concentration
Oceanography
Presentation Type
Poster Presentation
Abstract
The process of transporting Particulate Organic Carbon (POC) to the deep ocean by gravitational sinking is crucial component of the biological carbon pump (BCP). However, observations in the mesopelagic zone show that a considerable portion of POC stock of small slow sinking particles (22 to 100 micrometer) cannot be explained by BCP alone and that an important contribution comes from turbulent mixing of the seasonal mixed-layer (ML) pump. Here, we implement a 1D Mellor-Yamada turbulent model based on seasonal surface wind stress and heat flux that combines particle sinking velocity with turbulent mixing dynamics to study changes in particle concentration with depth. The comparison between observations of vertical particle distributions of small and slow-sinking particles in the Atlantic Ocean near Bermuda and model results are promising and may explain the role that the mixed-layer pump plays in these particle distributions. The model allows us to evaluate the impact of wind and wave mixing as well as stratification on particle distribution and transport.
Keywords
Particle distribution, Mixed-layered pump, Mellor-Yamada model
Biological-Physical Interaction of Particle Distribution: The Turbulent Mixed-Layer Pump and Particle Sinking Explored Through Modeling and Observations
The process of transporting Particulate Organic Carbon (POC) to the deep ocean by gravitational sinking is crucial component of the biological carbon pump (BCP). However, observations in the mesopelagic zone show that a considerable portion of POC stock of small slow sinking particles (22 to 100 micrometer) cannot be explained by BCP alone and that an important contribution comes from turbulent mixing of the seasonal mixed-layer (ML) pump. Here, we implement a 1D Mellor-Yamada turbulent model based on seasonal surface wind stress and heat flux that combines particle sinking velocity with turbulent mixing dynamics to study changes in particle concentration with depth. The comparison between observations of vertical particle distributions of small and slow-sinking particles in the Atlantic Ocean near Bermuda and model results are promising and may explain the role that the mixed-layer pump plays in these particle distributions. The model allows us to evaluate the impact of wind and wave mixing as well as stratification on particle distribution and transport.