Application of a lagrangian transport model to organo-mineral aggregates within the Nazaré canyon

[摘要] In this study, a hydrodynamic model was applied to the Nazaré submarinecanyon with boundary forcing provided by an operational forecast model forthe west Iberian coast for the spring of 2009. After validation, a lagrangiantransport model was coupled to the hydrodynamic model to study and comparethe transport patterns of three different classes of organo-mineralaggregates along the Nazaré canyon. The results show that the transportin the canyon is neither constant, nor unidirectional and that there arepreferential areas where deposited matter is resuspended and redistributed.The transport of the larger class size of organo-mineral aggregates(2000 μm and 4000 μm) is less pronounced, and a decreasein the phytodetrital carbon flux along the canyon is observed. During themodelled period, the Nazaré canyon acts as a depocentre of sedimentaryorganic matter rather than a conduit of organo-mineral aggregates to the deepsea, as has been reported by other authors. The results of this study arecrucial for the understanding of the oceanic carbon sequestration at thecontinental margin, and therefore important for evaluating the role ofsubmarine canyons within the global carbon cycle.

[学科分类] 地球化学与岩石