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

Related in: MedlinePlus

Cross section of the flow field.Vertical cross-sections of (a) density (kg m−3), (b) current speed (m s−1), and (c) vertical velocity (m day−1) along the transect shown in Fig. 2d. For vertical velocities, contours in red (blue) color represent upward (downward) velocities.
© Copyright Policy
Related In: Results  -  Collection

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

pone-0111482-g004: Cross section of the flow field.Vertical cross-sections of (a) density (kg m−3), (b) current speed (m s−1), and (c) vertical velocity (m day−1) along the transect shown in Fig. 2d. For vertical velocities, contours in red (blue) color represent upward (downward) velocities.

Mentions: The vertical density structure of the circulation field is depicted by Fig. 4a for the transect that crosses the WAG diagonally and then extends zonally across the EAG towards the Algerian basin (see Fig. 2d). It identified the low density anticyclonic gyres with isopycnals in the range of ∼27.0–28.0 kg m−3 deepening towards their centers within the upper 100 m layer and to 28.5 kg m−3 between 150–200 m. The latter represented the interface between the Atlantic and Mediterranean water masses, in agreement with previous observations [8], [14]. Two frontal zones for both the WAG and the EAG were identified by the upward sloping isopycnals greater than 27.5 kg m−3 towards the surface. The vertical structure of the jet accompanying these well-marked narrow frontal zones extended to 200 m with a gradual reduction in its strength from 0.7 m s−1 at the surface around the WAG and 0.3–04 m s−1 elsewhere (Fig. 4b). As stated previously, the strength of the jet and its vertical dimension reduced eastward with the Almeria-Oran front being the weakest one.


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)

Cross section of the flow field.Vertical cross-sections of (a) density (kg m−3), (b) current speed (m s−1), and (c) vertical velocity (m day−1) along the transect shown in Fig. 2d. For vertical velocities, contours in red (blue) color represent upward (downward) velocities.
© Copyright Policy
Related In: Results  -  Collection

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

pone-0111482-g004: Cross section of the flow field.Vertical cross-sections of (a) density (kg m−3), (b) current speed (m s−1), and (c) vertical velocity (m day−1) along the transect shown in Fig. 2d. For vertical velocities, contours in red (blue) color represent upward (downward) velocities.
Mentions: The vertical density structure of the circulation field is depicted by Fig. 4a for the transect that crosses the WAG diagonally and then extends zonally across the EAG towards the Algerian basin (see Fig. 2d). It identified the low density anticyclonic gyres with isopycnals in the range of ∼27.0–28.0 kg m−3 deepening towards their centers within the upper 100 m layer and to 28.5 kg m−3 between 150–200 m. The latter represented the interface between the Atlantic and Mediterranean water masses, in agreement with previous observations [8], [14]. Two frontal zones for both the WAG and the EAG were identified by the upward sloping isopycnals greater than 27.5 kg m−3 towards the surface. The vertical structure of the jet accompanying these well-marked narrow frontal zones extended to 200 m with a gradual reduction in its strength from 0.7 m s−1 at the surface around the WAG and 0.3–04 m s−1 elsewhere (Fig. 4b). As stated previously, the strength of the jet and its vertical dimension reduced eastward with the Almeria-Oran front being the weakest one.

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
Related in: MedlinePlus