Limits...
Fueling plankton production by a meandering frontal jet: a case study for the Alboran Sea (Western Mediterranean).

Oguz T, Macias D, Garcia-Lafuente J, Pascual A, Tintore J - PLoS ONE (2014)

Bottom Line: Biological production is larger in the western part of the basin and decreases eastwards with the gradual weakening of the jet.The higher production at the subsurface levels suggests that the Alboran Sea is likely more productive than predicted by the satellite chlorophyll data.The Mediterranean water mass away from the jet and the interiors of the western and eastern anticyclonic gyres remain unproductive.

View Article: PubMed Central - PubMed

Affiliation: SOCIB, Balearic Islands Coastal Ocean Observing and Forecasting System, Palma de Mallorca, Spain; Institute of Marine Sciences, Middle East Technical University, Erdemli, Mersin, Turkey.

ABSTRACT
A three dimensional biophysical model was employed to illustrate the biological impacts of a meandering frontal jet, in terms of efficiency and persistency of the autotrophic frontal production, in marginal and semi-enclosed seas. We used the Alboran Sea of the Western Mediterranean as a case study. Here, a frontal jet with a width of 15-20 km, characterized by the relatively low density Atlantic water mass, flows eastward within the upper 100 m as a marked meandering current around the western and the eastern anticyclonic gyres prior to its attachment to the North African shelf/slope topography of the Algerian basin. Its inherent nonlinearity leads to the development of a strong ageostrophic cross-frontal circulation that supplies nutrients into the nutrient-starved euphotic layer and stimulates phytoplankton growth along the jet. Biological production is larger in the western part of the basin and decreases eastwards with the gradual weakening of the jet. The higher production at the subsurface levels suggests that the Alboran Sea is likely more productive than predicted by the satellite chlorophyll data. The Mediterranean water mass away from the jet and the interiors of the western and eastern anticyclonic gyres remain unproductive.

Show MeSH
Surface phytoplankton and zooplankton biomass.Horizontal distributions of (a) surface phytoplankton biomass and (b) surface zooplankton biomass (mmol N m−3) at day 120.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4221033&req=5

pone-0111482-g008: Surface phytoplankton and zooplankton biomass.Horizontal distributions of (a) surface phytoplankton biomass and (b) surface zooplankton biomass (mmol N m−3) at day 120.

Mentions: An interesting feature of the narrow frontal region of approximately 15–20 km width along the jet trajectory revealed opposite phytoplankton and zooplankton biomass distributions. For example, the surface phytoplankton biomass was highest at the frontal zone of the WAG (Fig. 8a) but the corresponding zooplankton biomass was much lower (Fig. 8b). The inefficiency of the secondary production (with respect to the primary production) in this region was apparently related to the adverse effect of strong along-front advection of the phytoplankton biomass. The reverse situation occurred at the Almeria-Oran frontal zone where the horizontal current was relatively weak and the ageostrophic dynamics was less effective. Thus, zooplankton may exert a more efficient grazing pressure on phytoplankton and present a biomass comparable with that of phytoplankton.


Fueling plankton production by a meandering frontal jet: a case study for the Alboran Sea (Western Mediterranean).

Oguz T, Macias D, Garcia-Lafuente J, Pascual A, Tintore J - PLoS ONE (2014)

Surface phytoplankton and zooplankton biomass.Horizontal distributions of (a) surface phytoplankton biomass and (b) surface zooplankton biomass (mmol N m−3) at day 120.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4221033&req=5

pone-0111482-g008: Surface phytoplankton and zooplankton biomass.Horizontal distributions of (a) surface phytoplankton biomass and (b) surface zooplankton biomass (mmol N m−3) at day 120.
Mentions: An interesting feature of the narrow frontal region of approximately 15–20 km width along the jet trajectory revealed opposite phytoplankton and zooplankton biomass distributions. For example, the surface phytoplankton biomass was highest at the frontal zone of the WAG (Fig. 8a) but the corresponding zooplankton biomass was much lower (Fig. 8b). The inefficiency of the secondary production (with respect to the primary production) in this region was apparently related to the adverse effect of strong along-front advection of the phytoplankton biomass. The reverse situation occurred at the Almeria-Oran frontal zone where the horizontal current was relatively weak and the ageostrophic dynamics was less effective. Thus, zooplankton may exert a more efficient grazing pressure on phytoplankton and present a biomass comparable with that of phytoplankton.

Bottom Line: Biological production is larger in the western part of the basin and decreases eastwards with the gradual weakening of the jet.The higher production at the subsurface levels suggests that the Alboran Sea is likely more productive than predicted by the satellite chlorophyll data.The Mediterranean water mass away from the jet and the interiors of the western and eastern anticyclonic gyres remain unproductive.

View Article: PubMed Central - PubMed

Affiliation: SOCIB, Balearic Islands Coastal Ocean Observing and Forecasting System, Palma de Mallorca, Spain; Institute of Marine Sciences, Middle East Technical University, Erdemli, Mersin, Turkey.

ABSTRACT
A three dimensional biophysical model was employed to illustrate the biological impacts of a meandering frontal jet, in terms of efficiency and persistency of the autotrophic frontal production, in marginal and semi-enclosed seas. We used the Alboran Sea of the Western Mediterranean as a case study. Here, a frontal jet with a width of 15-20 km, characterized by the relatively low density Atlantic water mass, flows eastward within the upper 100 m as a marked meandering current around the western and the eastern anticyclonic gyres prior to its attachment to the North African shelf/slope topography of the Algerian basin. Its inherent nonlinearity leads to the development of a strong ageostrophic cross-frontal circulation that supplies nutrients into the nutrient-starved euphotic layer and stimulates phytoplankton growth along the jet. Biological production is larger in the western part of the basin and decreases eastwards with the gradual weakening of the jet. The higher production at the subsurface levels suggests that the Alboran Sea is likely more productive than predicted by the satellite chlorophyll data. The Mediterranean water mass away from the jet and the interiors of the western and eastern anticyclonic gyres remain unproductive.

Show MeSH