Abstract
The temporal evolution of the vertical export flux at the DYFAMED time-series station (Ligurian Sea) over the last 20years reveals a strong interannual variability. Winter convection allows particulate (and dissolved) matter to be vertically exported (“flush-down” effect). The efficiency of this process determines also the concentration of nutrients brought to surface waters and, therefore, the intensity of the subsequent phytoplankton bloom. The sequence “convection-bloom” is the main driving force of vertical export flux in this region. The present work attempts to better identify the parameters that control vertical export flux dynamics by observing a 20year time-series in relation with the temporal variability of mixed layer depth and surface primary production. The consequences of a more stratified water column in the future on biological productivity and vertical export flux are pointed out.
Highlights
IntroductionThe Mediterranean Sea is a semi-enclosed basin where evaporation outweighs the sum of freshwater inputs (precipitations and rivers) with a negative balance of approximately 10% (Béthoux, 1979)
The Mediterranean Sea is a semi-enclosed basin where evaporation outweighs the sum of freshwater inputs with a negative balance of approximately 10% (Béthoux, 1979)
A bias in the ocean color surface Chl-a estimations obtained with the NASA standard algorithm (O’Reilly et al, 2000) was identified for the Mediterranean Sea (30% on the average, Bosc et al, 2004; Claustre et al, 2002; D’Ortenzio et al, 2002; Volpe et al, 2007), the NASA standard product was preferred to regional algorithms, because we focused more on the relative changes in phytoplankton dynamics than on the absolute values
Summary
The Mediterranean Sea is a semi-enclosed basin where evaporation outweighs the sum of freshwater inputs (precipitations and rivers) with a negative balance of approximately 10% (Béthoux, 1979). In this concentration basin, prevailing winds in winter lead through cooling and evaporation to an increase in the density of the surface waters inducing vertical convection (Millot and Taupier-Letage, 2005; Stabholz et al 2013). This is a key process for the Mediterranean biogeochemistry because vertical convection brings amounts of nutrient from depths to surface layers and enables early spring phytoplankton blooms (Migon et al, 2002).
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
