2011/12/31 by Ismael Hernández-Carrasco, Vincent Rossi, Emilio Hernández-García +2 · 41 citations
Earth and Planetary Sciences · Environmental Science · Physics and Astronomy · #Advection #Aquatic Ecosystems and Biodiversity #Context (archaeology) #Dispersion (optics) #Forcing (mathematics) #Marine and coastal ecosystems #Mesoscale meteorology #Oceanographic and Atmospheric Processes #Plankton #Submarine pipeline #Upwelling #nlin.CD #physics.ao-ph
paper · pdf · doi:10.1016/j.dsr.2013.09.003
published in Deep Sea Research Part I Oceanographic Research Papers 83, 65-80 (Elsevier BV)
openalex publication_date 2013/09/29 · arxiv created 2013/11/05 · arxiv updated 2014/01/14 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Recent studies, both based on remote sensed data and coupled models, showed a reduction of biological productivity due to vigorous horizontal stirring in upwelling areas. In order to better understand this phenomenon, we consider a system of oceanic flow from the Benguela area coupled with a simple biogeochemical model of Nutrient-Phyto-Zooplankton (NPZ) type. For the flow three different surface velocity fields are considered: one derived from satellite altimetry data, and the other two from a regional numerical model at two different spatial resolutions. We compute horizontal particle dispersion in terms of Lyapunov Exponents, and analyzed their correlations with phytoplankton concentrations. Our modelling approach confirms that in the south Benguela there is a reduction of biological activity when stirring is increased. Two-dimensional offshore advection and latitudinal difference in Primary Production, also mediated by the flow, seem to be the dominant processes involved. We estimate that mesoscale processes are responsible for 30 to 50% of the offshore fluxes of biological tracers. In the northern area, other factors not taken into account in our simulation are influencing the ecosystem. We suggest explanations for these results in the context of studies performed in other eastern boundary upwelling areas.