scholarly journals Climate-Driven Change in the North Atlantic and Arctic Oceans Can Greatly Reduce the Circulation of the North Sea

2018 ◽  
Vol 45 (21) ◽  
pp. 11,827-11,836 ◽  
Author(s):  
Jason Holt ◽  
Jeff Polton ◽  
John Huthnance ◽  
Sarah Wakelin ◽  
Enda O'Dea ◽  
...  
Keyword(s):  
North Sea ◽  
North Atlantic ◽  
The North ◽  
The North Sea ◽  
The North Atlantic

scholarly journals The carbon budget of the North Sea

2005 ◽  
Vol 2 (1) ◽  
pp. 87-96 ◽  
Author(s):  
H. Thomas ◽  
Y. Bozec ◽  
H. J. W. de Baar ◽  
K. Elkalay ◽  
M. Frankignoulle ◽  
...  
Keyword(s):  
Atlantic Ocean ◽  
Continental Shelf ◽  
North Sea ◽  
North Atlantic ◽  
Carbon Budget ◽  
North Atlantic Ocean ◽  
Carbon Sink ◽  
The North ◽  
The North Sea ◽  
The North Atlantic

Abstract. A carbon budget has been established for the North Sea, a shelf sea on the NW European continental shelf. The carbon exchange fluxes with the North Atlantic Ocean dominate the gross carbon budget. The net carbon budget – more relevant to the issue of the contribution of the coastal ocean to the marine carbon cycle – is dominated by the carbon inputs from rivers, the Baltic Sea and the atmosphere. The North Sea acts as a sink for organic carbon and thus can be characterised as a heterotrophic system. The dominant carbon sink is the final export to the North Atlantic Ocean. More than 90% of the CO2 taken up from the atmosphere is exported to the North Atlantic Ocean making the North Sea a highly efficient continental shelf pump for carbon.

scholarly journals Synchronous ecological regime shifts in the central Baltic and the North Sea in the late 1980s

2005 ◽  
Vol 62 (7) ◽  
pp. 1205-1215 ◽  
Author(s):  
J. Alheit ◽  
C. Möllmann ◽  
J. Dutz ◽  
G. Kornilovs ◽  
P. Loewe ◽  
...  
Keyword(s):  
North Sea ◽  
North Atlantic ◽  
Climatic Variability ◽  
Regime Shifts ◽  
Trophic Levels ◽  
Copepod Species ◽  
The North ◽  
The North Sea ◽  
The North Atlantic ◽  
Low Levels

Abstract The index of the North Atlantic Oscillation, the dominant mode of climatic variability in the North Atlantic region, changed in the late 1980s (1987–1989) from a negative to a positive phase. This led to regime shifts in the ecology of the North Sea (NS) and the central Baltic Sea (CBS), which involved all trophic levels in the pelagial of these two neighbouring continental shelf seas. Increasing air and sea surface temperatures, which affected critical physical and biological processes, were the main direct and indirect driving forces. After 1987, phytoplankton biomass in both systems increased and the growing season was extended. The composition of phyto- and zooplankton communities in both seas changed conspicuously, e.g. dinoflagellate abundance increased and diatom abundance decreased in the CBS. Key copepod species that are essential in fish diets experienced pronounced changes in biomass. Abundance of Calanus finmarchicus (NS) and Pseudocalanus sp. (CBS) fell to low levels, whereas C. helgolandicus (NS) and Temora longicornis and Acartia spp. (CBS) were persistently abundant. These changes in biomass of different copepod species had dramatic consequences on biomass, fisheries, and landings of key fish species: North Sea cod declined, cod in the CBS remained at low levels, and CBS sprat reached unprecedented high biomass levels resulting in high yields. The synchronous regime shifts in NS and CBS resulted in profound changes in both marine ecosystems. However, the reaction of fish populations to the bottom-up mechanisms caused by the same climatic shift was very different for the three fish stocks.

scholarly journals Rapid and sustained environmental responses to global warming: The Paleocene–Eocene Thermal Maximum in the eastern North Sea

2020 ◽  
Author(s):  
Ella W. Stokke ◽  
Morgan T. Jones ◽  
Lars Riber ◽  
Haflidi Haflidason ◽  
Ivar Midtkandal ◽  
...  
Keyword(s):  
Global Warming ◽  
North Sea ◽  
North Atlantic ◽  
Hydrological Cycle ◽  
Clay Fraction ◽  
The North ◽  
Thermal Maximum ◽  
The North Sea ◽  
The North Atlantic ◽  
The Impact

Abstract. The Paleocene–Eocene Thermal Maximum (PETM; ~ 55.9 Ma) was a period of rapid and sustained global warming associated with significant carbon emissions. It coincided with the North Atlantic opening and emplacement of the North Atlantic Igneous Province (NAIP), suggesting a possible causal relationship. Only a very limited number of PETM studies exist from the North Sea, despite its ideal position for tracking the impact of both changing climate and the NAIP explosive and effusive activity. Here we present sedimentological, mineralogical, and geochemical proxy data from Denmark in the eastern North Sea, exploring the environmental response to the PETM. An increase in the chemical index of alteration and a kaolinite content up to 50 % of the clay fraction indicate an influx of terrestrial input shortly after the PETM onset and during the recovery, likely due to an intensified hydrological cycle. The volcanically derived minerals zeolite and smectite comprise up to 36 % and 90 % of the bulk and clay mineralogy respectively, highlighting the NAIPs importance as a sediment source for the North Sea and in increasing the rate of silicate weathering during the PETM. XRF element core scans also reveal possible hitherto unknown NAIP ash deposition both prior to and during the PETM. Geochemical proxies show that an anoxic environment persisted during the PETM body, possibly reaching euxinic conditions in the upper half with high concentrations of Mo (> 30 ppm), S (~ 4 wt %), and pyrite (~ 7 % of bulk), and low Th/U (

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