Abstract
Three stations along a productivity gradient north of the Canary Islands were investigated for surface-water properties, particle flux, and composition (biogenic and lithogenic components, and stable nitrogen isotope composition, δ15sN) and export production. Investigation sites along the east-west transect off the NW African upwelling margin included the European Station for Time-Series in the Ocean, Canary Islands (ESTOC), one location contiguous to the NW African upwelling zone in the Eastern Boundary Current (EBC) and one station north of the island La Palma (LP). The seasonality of surface-water properties along the transect was mainly influenced by the winter cooling and simultaneous phytoplankton maximum and, in addition at EBC, by nearby upwelling. Accordingly, particle flux and composition along the transect were closely linked to the winter bloom sedimentation and upwelling related enhanced plankton biomass stemming from the primary upwelling and the Cape Yubi filament at EBC. During all seasons, particle flux was highest at EBC and had the highest contribution of biogenic opal and lithogenic components, and the lowest δ15N compared to the offshore stations. But contrary to what would be expected from the productivity gradient, particle flux did not decrease from ESTOC to LP. Below the upper several hundred meters, particle flux was enhanced by additional particle input along the entire transect, manifested by an increase of flux with depth and lower δ15N values. We offer a scenario in which intermediate nepheloid layers originating from the primary upwelling as well as particle dispersion from upwelling filaments, mainly the Cape Ghir filament, impact on the trap stations as far as 700 km into the open ocean. This study contributes to our understanding of the poorly resolved biogeochemical transition between the productive shelf and subtropical gyre provinces.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 3561-3576 |
| Number of pages | 16 |
| Journal | Deep-Sea Research Part II: Topical Studies in Oceanography |
| Volume | 49 |
| Issue number | 17 |
| DOIs | |
| State | Published - 2002 |
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ASJC Scopus subject areas
- Aquatic Science
- Geology
- Oceanography
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Seasonality of surface water properties and particle flux along a productivity gradient off NW Africa. / Neuer, Susanne; Freudenthal, Tim; Davenport, Robert; Llinás, Octavio; Rueda, Mariá José.
In: Deep-Sea Research Part II: Topical Studies in Oceanography, Vol. 49, No. 17, 2002, p. 3561-3576.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Seasonality of surface water properties and particle flux along a productivity gradient off NW Africa
AU - Neuer, Susanne
AU - Freudenthal, Tim
AU - Davenport, Robert
AU - Llinás, Octavio
AU - Rueda, Mariá José
PY - 2002
Y1 - 2002
N2 - Three stations along a productivity gradient north of the Canary Islands were investigated for surface-water properties, particle flux, and composition (biogenic and lithogenic components, and stable nitrogen isotope composition, δ15sN) and export production. Investigation sites along the east-west transect off the NW African upwelling margin included the European Station for Time-Series in the Ocean, Canary Islands (ESTOC), one location contiguous to the NW African upwelling zone in the Eastern Boundary Current (EBC) and one station north of the island La Palma (LP). The seasonality of surface-water properties along the transect was mainly influenced by the winter cooling and simultaneous phytoplankton maximum and, in addition at EBC, by nearby upwelling. Accordingly, particle flux and composition along the transect were closely linked to the winter bloom sedimentation and upwelling related enhanced plankton biomass stemming from the primary upwelling and the Cape Yubi filament at EBC. During all seasons, particle flux was highest at EBC and had the highest contribution of biogenic opal and lithogenic components, and the lowest δ15N compared to the offshore stations. But contrary to what would be expected from the productivity gradient, particle flux did not decrease from ESTOC to LP. Below the upper several hundred meters, particle flux was enhanced by additional particle input along the entire transect, manifested by an increase of flux with depth and lower δ15N values. We offer a scenario in which intermediate nepheloid layers originating from the primary upwelling as well as particle dispersion from upwelling filaments, mainly the Cape Ghir filament, impact on the trap stations as far as 700 km into the open ocean. This study contributes to our understanding of the poorly resolved biogeochemical transition between the productive shelf and subtropical gyre provinces.
AB - Three stations along a productivity gradient north of the Canary Islands were investigated for surface-water properties, particle flux, and composition (biogenic and lithogenic components, and stable nitrogen isotope composition, δ15sN) and export production. Investigation sites along the east-west transect off the NW African upwelling margin included the European Station for Time-Series in the Ocean, Canary Islands (ESTOC), one location contiguous to the NW African upwelling zone in the Eastern Boundary Current (EBC) and one station north of the island La Palma (LP). The seasonality of surface-water properties along the transect was mainly influenced by the winter cooling and simultaneous phytoplankton maximum and, in addition at EBC, by nearby upwelling. Accordingly, particle flux and composition along the transect were closely linked to the winter bloom sedimentation and upwelling related enhanced plankton biomass stemming from the primary upwelling and the Cape Yubi filament at EBC. During all seasons, particle flux was highest at EBC and had the highest contribution of biogenic opal and lithogenic components, and the lowest δ15N compared to the offshore stations. But contrary to what would be expected from the productivity gradient, particle flux did not decrease from ESTOC to LP. Below the upper several hundred meters, particle flux was enhanced by additional particle input along the entire transect, manifested by an increase of flux with depth and lower δ15N values. We offer a scenario in which intermediate nepheloid layers originating from the primary upwelling as well as particle dispersion from upwelling filaments, mainly the Cape Ghir filament, impact on the trap stations as far as 700 km into the open ocean. This study contributes to our understanding of the poorly resolved biogeochemical transition between the productive shelf and subtropical gyre provinces.
UR - http://www.scopus.com/inward/record.url?scp=0036387932&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0036387932&partnerID=8YFLogxK
U2 - 10.1016/S0967-0645(02)00098-X
DO - 10.1016/S0967-0645(02)00098-X
M3 - Article
AN - SCOPUS:0036387932
VL - 49
SP - 3561
EP - 3576
JO - Deep-Sea Research Part II: Topical Studies in Oceanography
JF - Deep-Sea Research Part II: Topical Studies in Oceanography
SN - 0967-0645
IS - 17
ER -