scholarly journals Carbon dynamics and CO<sub>2</sub> air-sea exchanges in the eutrophied coastal waters of the Southern Bight of the North Sea: a modelling study

2004 ◽  
Vol 1 (2) ◽  
pp. 147-157 ◽  
Author(s):  
N. Gypens ◽  
C. Lancelot ◽  
A. V. Borges
Keyword(s):  
Surface Water ◽  
Coastal Zone ◽  
North Sea ◽  
Coastal Waters ◽  
Co2 Flux ◽  
Open Ocean ◽  
Atmospheric Co2 ◽  
Southern Bight ◽  
The North ◽  
The North Sea

Abstract. A description of the carbonate system has been incorporated in the MIRO biogeochemical model to investigate the contribution of diatom and Phaeocystis blooms to the seasonal dynamics of air-sea CO2 exchanges in the Eastern Channel and Southern Bight of the North Sea, with focus on the eutrophied Belgian coastal waters. For this application, the model was implemented in a simplified three-box representation of the hydrodynamics with the open ocean boundary box ‘Western English Channel’ (WCH) and the ‘French Coastal Zone’ (FCZ) and ‘Belgian Coastal Zone’ (BCZ) boxes receiving carbon and nutrients from the rivers Seine and Scheldt, respectively. Results were obtained by running the model for the 1996–1999 period. The simulated partial pressures of CO2 (pCO2) were successfully compared with data recorded over the same period in the central BCZ at station 330 (51°26.05′ N; 002°48.50′ E). Budget calculations based on model simulations of carbon flow rates indicated for BCZ a low annual sink of atmospheric CO2 (−0.17 mol C m-2 y-1). On the opposite, surface water pCO2 in WCH was estimated to be at annual equilibrium with respect to atmospheric CO2. The relative contribution of biological, chemical and physical processes to the modelled seasonal variability of pCO2 in BCZ was further explored by running model scenarios with separate closures of biological activities and/or river inputs of carbon. The suppression of biological processes reversed direction of the CO2 flux in BCZ that became, on an annual scale, a significant source for atmospheric CO2 (+0.53 mol C m-2 y-1). Overall biological activity had a stronger influence on the modelled seasonal cycle of pCO2 than temperature. Especially Phaeocystis colonies which growth in spring were associated with an important sink of atmospheric CO2 that counteracted the temperature-driven increase of pCO2 at this period of the year. However, river inputs of organic and inorganic carbon were shown to increase the surface water pCO2 and hence the emission of CO2 to the atmosphere. Same calculations conducted in WCH, showed that temperature was the main factor controlling the seasonal pCO2 cycle in these open ocean waters. The effect of interannual variations of fresh water discharge (and related nutrient and carbon inputs), temperature and wind speed was further explored by running scenarios with forcing typical of two contrasted years (1996 and 1999). Based on these simulations, the model predicts significant variations in the intensity and direction of the annual air-sea CO2 flux.

scholarly journals Carbon dynamics and CO<sub>2</sub> air-sea exchanges in the eutrophied coastal waters of the southern bight of the North Sea: a modelling study

2004 ◽  
Vol 1 (1) ◽  
pp. 561-589 ◽  
Author(s):  
N. Gypens ◽  
C. Lancelot ◽  
A. V. Borges
Keyword(s):  
Coastal Zone ◽  
North Sea ◽  
Coastal Waters ◽  
Water Discharge ◽  
Co2 Flux ◽  
Atmospheric Co2 ◽  
Biogeochemical Model ◽  
Southern Bight ◽  
The North ◽  
The North Sea

Abstract. A description of the carbonate system has been incorporated in the MIRO biogeochemical model to investigate the contribution of diatom and Phaeocystis blooms to the seasonal dynamics of air-sea CO2 exchanges in the Eastern Channel and Southern Bight of the North Sea with focus on the eutrophied Belgian coastal waters. For this application the model was implemented in a simplified three-box representation of the hydrodynamics including the open ocean boundary box ‘Western English Channel’ (WCH) and the ‘French Coastal Zone’ (FCZ) and ‘Belgian Coastal Zone’ (BCZ) boxes receiving carbon and nutrients from the rivers Seine and Scheldt, respectively. Results were obtained by running the model for the 1996–1999 period. The predicted partial pressures of CO2 (pCO2) were successfully compared with data recorded over the same period in the central BCZ at station 330 (51°26.05′ N; 002°48.50′ E). Budget calculations based on model simulations of carbon flow rates indicated for BCZ a low annual sink of atmospheric CO2 (−0.17 mol C m−2 y−1). On the opposite surface water pCO2 in WCH was estimated in annual equilibrium with respect to atmospheric CO2. The relative contribution of biological, chemical and physical processes to the modelled pCO2 seasonal variability in BCZ was further explored by running model scenarios with separate closures of biological activities and carbon rivers inputs. The suppression of biological processes reversed direction of the CO2 flux in BCZ that became, on an annual scale, a significant source for atmospheric CO2 (+0.58 mol C m−2 y−1). Overall biological activity had a stronger influence on the modelled seasonal cycle of pCO2 than temperature. Especially Phaeocystis colonies which spring growth was associated with an important sink of atmospheric CO2 that counteracted the temperature-driven increase of pCO2 in spring. On the other hand, river inputs of organic and inorganic carbon were shown to increasing water pCO2 and hence emission of CO2 to the atmosphere. Same calculations conducted in WCH, showed that temperature was the main factor controlling the seasonal pCO2 cycle in these waters. The effect of interannual variations of fresh water discharge (and related nutrient and carbon inputs), temperature and wind speed was further explored by running scenarios with forcings typical of two contrasted years (1996 and 1999). Based on these simulations, the model predicts significant variations in the intensity and direction of the annual air-sea CO2 flux.

Benthos of a Sublittoral Sandbank in the Southern Bight of the North Sea: General Considerations

1982 ◽  
Vol 62 (3) ◽  
pp. 549-557 ◽  
Author(s):  
K. A. Willems ◽  
C. Vanosmael ◽  
D. Claeys ◽  
M. Vincx ◽  
C. Heip
Keyword(s):  
North Sea ◽  
Coastal Waters ◽  
High Energy ◽  
Tidal Currents ◽  
Physical Disturbance ◽  
Sea Floor ◽  
Southern Bight ◽  
The North ◽  
The North Sea

In two previous papers (Vanosmael et al. 1982; Willems et al. 1982) the macrofauna and meiofauna of a sublittoral sandbank in the Belgian coastal waters of the North Sea were described. This sandbank, the Kwinte Bank, is one of a series of parallel linear banks, the Flemish Banks, which are 15–25 km long and 3–6 km wide and rise about 25 m above the surrounding sea-floor. They are stressed, high-energy environments, subject to extreme physical disturbance by the very strong tidal currents which run parallel to the long axis of the sandbank and which put the whole upper layer of the sediment in a state of suspension at times.

Biological production of methyl bromide in the coastal waters of the North Sea and open ocean of the northeast Atlantic

1999 ◽  
Vol 64 (4) ◽  
pp. 267-285 ◽  
Author(s):  
J.M Baker ◽  
C.E Reeves ◽  
P.D Nightingale ◽  
S.A Penkett ◽  
S.W Gibb ◽  
...  
Keyword(s):  
North Sea ◽  
Methyl Bromide ◽  
Coastal Waters ◽  
Open Ocean ◽  
Biological Production ◽  
Northeast Atlantic ◽  
The North ◽  
The North Sea

First Record of the American Jack Knife Clam Ensis Directus on the French Coast of the North Sea

1993 ◽  
Vol 73 (1) ◽  
pp. 233-235 ◽  
Author(s):  
C. Luczak ◽  
J.-M. Dewarumez ◽  
K. Essink
Keyword(s):  
North Sea ◽  
Coastal Waters ◽  
New Records ◽  
First Record ◽  
English Channel ◽  
Southern Bight ◽  
The North ◽  
German Coast ◽  
The North Sea ◽  
First Time

Ensis directus (Bivalvia: Solenidae) was noted for the first time along the French coast of the North Sea in June 1991. High numbers of post larvae after a period of northerly winds indicate that settled larvae originated from adult populations in Belgian or Dutch coastal waters. Future dispersal of Ensis directus could be used as a biological tracer of coastal water movements between the Southern Bight of the North Sea and the English Channel.The American jack knife clam, Ensis directus (Conrad, 1843), synonym Ensis americanus (Binney, 1870)sensu van Urk (1964,1972), was discovered in Europe in the German Bight for the first time in June 1979 (Von Cosel et al., 1982). This species is assumed to have been transported in its larval stage by a ship containing ballast water. Considering the dimensions of the specimens, this probably happened in the first half of 1978 (Von Cosel et al., 1982; Mühlenhardt-Siegel et al., 1983). Since then this species has spread rapidly in the North Sea in subtidal and intertidal areas. Dense populations were found along the German coast within a few years (Von Cosel et al., 1982; Mühlenhardt-Siegel et al., 1983; Swennen et al., 1985). In 1986 Ensis directus was reported from the north and east Danish coasts as far as the Belgian coast (Kerkhof & Dumoulin, 1987) (Figure 1). Since then no new records have been reported.

Temperature, Salinity and Plankton in the Eastern North Atlantic and Coastal Waters of Britain, 1957.: I. The Characterisation and Distribution of Surface Waters

1963 ◽  
Vol 20 (3) ◽  
pp. 789-826 ◽  
Author(s):  
B. McK. Bary
Keyword(s):  
North Sea ◽  
North Atlantic ◽  
Coastal Waters ◽  
Water Bodies ◽  
English Channel ◽  
Oceanic Water ◽  
Climatic Fluctuations ◽  
The North ◽  
The North Sea ◽  
Eastern North Atlantic

Monthly temperature-salinity diagrams for 1957 have demonstrated that three surface oceanic "water bodies" were consistently present in the eastern North Atlantic; two are regarded as modified North Atlantic Central water which give rise to the third by mixing. As well in the oceanic areas, large and small, high or low salinity patches of water were common. Effects of seasonal climatic fluctuations differed in the several oceanic water bodies. In coastal waters, differences in properties and in seasonal and annual cycles of the properties distinguish the waters from the North Sea, English Channel and the western entrance to the Channel.The geographic distributions of the oceanic waters are consistent with "northern" and "southern" water bodies mixing to form a "transitional" water. Within this distribution there are short-term changes in boundaries and long-term (seasonal) changes in size of the water bodies.Water in the western approaches to the English Channel appeared to be influenced chiefly by the mixed, oceanic transitional water; oceanic influences in the North Sea appear to have been from northern and transitional waters.

scholarly journals An estimation of the effects of Ensis directus on the transport and burial of silt in the near-shore Dutch coastal zone of the North Sea

2017 ◽  
Vol 127 ◽  
pp. 95-104 ◽  
Author(s):  
Rob Witbaard ◽  
Magda J.N. Bergman ◽  
Evaline van Weerlee ◽  
Gerard C.A. Duineveld
Keyword(s):  
Coastal Zone ◽  
North Sea ◽  
The North ◽  
Near Shore ◽  
The North Sea

scholarly journals The impact of sedimentary alkalinity release on the water column CO<sub>2</sub> system in the North Sea

2016 ◽  
Vol 13 (3) ◽  
pp. 841-863 ◽  
Author(s):  
H. Brenner ◽  
U. Braeckman ◽  
M. Le Guitton ◽  
F. J. R. Meysman
Keyword(s):  
Coastal Zone ◽  
North Sea ◽  
Dissolved Inorganic Carbon ◽  
Co2 Uptake ◽  
Overlying Water ◽  
Southern North Sea ◽  
The North ◽  
Alkalinity Generation ◽  
The North Sea ◽  
The Impact

Abstract. It has been previously proposed that alkalinity release from sediments can play an important role in the carbonate dynamics on continental shelves, lowering the pCO2 of seawater and hence increasing the CO2 uptake from the atmosphere. To test this hypothesis, sedimentary alkalinity generation was quantified within cohesive and permeable sediments across the North Sea during two cruises in September 2011 (basin-wide) and June 2012 (Dutch coastal zone). Benthic fluxes of oxygen (O2), alkalinity (AT) and dissolved inorganic carbon (DIC) were determined using shipboard closed sediment incubations. Our results show that sediments can form an important source of alkalinity for the overlying water, particularly in the shallow southern North Sea, where high AT and DIC fluxes were recorded in near-shore sediments of the Belgian, Dutch and German coastal zone. In contrast, fluxes of AT and DIC are substantially lower in the deeper, seasonally stratified, northern part of the North Sea. Based on the data collected, we performed a model analysis to constrain the main pathways of alkalinity generation in the sediment, and to quantify how sedimentary alkalinity drives atmospheric CO2 uptake in the southern North Sea. Overall, our results show that sedimentary alkalinity generation should be regarded as a key component in the CO2 dynamics of shallow coastal systems.

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