SST anomalies in the north sea in relation to the North Atlantic Oscillation and the influence on the theoretical spawning time of fish

1997 ◽  
Vol 49 (2-3) ◽  
pp. 267-275 ◽  
Author(s):  
Joachim W. Dippner
Keyword(s):  
North Atlantic Oscillation ◽  
North Sea ◽  
North Atlantic ◽  
The North ◽  
The North Sea ◽  
Spawning Time ◽  
The North Atlantic ◽  
The North Atlantic Oscillation ◽  
Sst Anomalies

Effect of the North Atlantic Oscillation on recruitment of Atlantic cod (Gadus morhua)

2004 ◽  
Vol 61 (9) ◽  
pp. 1558-1564 ◽  
Author(s):  
K Brander ◽  
R Mohn
Keyword(s):  
North Atlantic Oscillation ◽  
North Sea ◽  
North Atlantic ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
The North ◽  
Nao Index ◽  
The North Sea ◽  
The North Atlantic ◽  
The North Atlantic Oscillation

We examine the effect of introducing an environmental factor — the North Atlantic Oscillation (NAO) index — into a stock–recruit relationship fitted to 13 North Atlantic cod (Gadus morhua) stocks and discuss the implications for management. The NAO has a significant effect on recruitment of four of the stocks (positive effect on recruitment in the North Sea, Baltic Sea, and Irish Sea; negative effect on recruitment at Iceland), and the pattern of positive and negative effects on all stocks is consistent with the geographic influence of the NAO on environmental variables. Observed variability in the NAO should be taken into account in interpreting the causes of past changes in cod stocks. The NAO index for the previous winter is available by April and thus may provide an early indication of the likely range of cod recruitment in the current year. In areas, such as the North Sea, where the effect is strong, medium- and long-term assessments of recruitment and yield of the cod stocks should consider likely future states of the NAO. The NAO can be used to represent environmental variability in stock projections and thereby provide a better basis for the estimation of risk.

scholarly journals The Relation between the North Atlantic Oscillation and SSTs in the North Atlantic Basin

2004 ◽  
Vol 17 (24) ◽  
pp. 4752-4759 ◽  
Author(s):  
Weile Wang ◽  
Bruce T. Anderson ◽  
Robert K. Kaufmann ◽  
Ranga B. Myneni
Keyword(s):  
North Atlantic Oscillation ◽  
Granger Causality ◽  
North Atlantic ◽  
Gulf Stream ◽  
Causal Relation ◽  
Causal Effect ◽  
The North ◽  
The North Atlantic ◽  
The North Atlantic Oscillation ◽  
Sst Anomalies

Abstract The authors use the notion of Granger causality to investigate the relationship between the North Atlantic Oscillation (NAO) index and the sea surface temperatures (SSTs) over the Northern Hemisphere. The Granger causality analysis ensures that any apparent oceanic influence upon the atmosphere (as measured by the NAO) is provided by the ocean and is not related to preexisting conditions within the NAO itself (and vice versa when looking at the atmospheric influence upon the ocean). Although this statistical technique does not imply physical forcing of one field on the other, it is generally more reliable compared to the simple lead/lagged correlation. Using this technique, the authors find that on seasonal time scales, the preceding NAO anomalies' influence on the wintertime SST field is rather restricted. Conversely, preceding SST anomalies have a statistically significant causal effect on the wintertime NAO. However, the causal relation between preceding SSTs and the wintertime NAO is limited to the Gulf Stream extension; in contrast to the canonical tripole SST pattern typically associated with the NAO, the authors do not find that SST anomalies in either the Greenland or subtropical regions have a significant causal effect on the NAO. These results suggest that the Gulf Stream SSTs have an important influence in initiating disturbances of the atmospheric circulation over the wintertime North Atlantic.

scholarly journals On sea level change in the North Sea influenced by the North Atlantic Oscillation: Local and remote steric effects

2014 ◽  
Vol 151 ◽  
pp. 186-195 ◽  
Author(s):  
Xinping Chen ◽  
Sönke Dangendorf ◽  
Nikesh Narayan ◽  
Kieran O'Driscoll ◽  
Michael N. Tsimplis ◽  
...  
Keyword(s):  
Sea Level ◽  
North Sea ◽  
North Atlantic ◽  
Sea Level Change ◽  
Steric Effects ◽  
Level Change ◽  
The North ◽  
The North Sea ◽  
The North Atlantic ◽  
The North Atlantic Oscillation

scholarly journals Influence of oceanic factors on Anguilla anguilla (L.) over the twentieth century in coastal habitats of the Skagerrak, southern Norway

2010 ◽  
Vol 278 (1704) ◽  
pp. 464-473 ◽  
Author(s):  
Caroline M. F. Durif ◽  
Jakob Gjøsæter ◽  
L. Asbjørn Vøllestad
Keyword(s):  
Time Series ◽  
North Atlantic Oscillation ◽  
North Sea ◽  
North Atlantic ◽  
Anguilla Anguilla ◽  
Sargasso Sea ◽  
Glass Eel ◽  
The North ◽  
The North Sea ◽  
The North Atlantic

The European eel ( Anguilla anguilla L.) is distributed in coastal and inland habitats all over Europe, but spawns in the Sargasso Sea and is thus affected by both continental and oceanic factors. Since the 1980s a steady decline has been observed in the recruitment of glass eels to freshwater and in total eel landings. The eel is considered as critically endangered on the International Union for the Conservation of Nature and Natural Resources Red List of species. The Skagerrak beach seine survey from Norway constitutes the longest fishery-independent dataset on yellow/silver eels (starting in 1904). The Skagerrak coastal region receives larvae born in the Sargasso Sea spawning areas that have followed the Gulf Stream/North Atlantic Drift before they penetrate far into the North Sea. The Skagerrak coastal time series is therefore particularly valuable for exploring the impacts of oceanic factors on fluctuations in eel recruitment abundance. Analyses showed that Sargasso Sea surface temperature was negatively correlated with eel abundance, with a lag of 12 years revealing a cyclic and detrimental effect of high temperatures on the newly hatched larvae. The North Atlantic Oscillation index and inflow of North Atlantic water into the North Sea were negatively correlated with eel abundance, with a lag of 11 years. Increased currents towards the North Atlantic during high North Atlantic Oscillation years may send larvae into the subpolar gyre before they are ready to metamorphose and settle, resulting in low recruitment in the northern part of the distribution area for these years. The Skagerrak time series was compared with glass eel recruitment to freshwater in the Netherlands (Den Oever glass eel time series), and similar patterns were found revealing a cycle linked to changes in oceanic factors affecting glass eel recruitment. The recent decline of eels in the Skagerrak also coincided with previously documented shifts in environmental conditions of the North Sea ecosystem.

scholarly journals Influence of the North Atlantic oscillation on the atmospheric levels of benzo[a]pyrene over Europe

2021 ◽  
Author(s):  
Pedro Jiménez-Guerrero ◽  
Nuno Ratola
Keyword(s):  
Spatial Pattern ◽  
North Atlantic Oscillation ◽  
North Atlantic ◽  
Transport Model ◽  
Regional Scale ◽  
The South ◽  
Climatic Fluctuations ◽  
The North ◽  
The North Atlantic ◽  
The North Atlantic Oscillation

AbstractThe atmospheric concentration of persistent organic pollutants (and of polycyclic aromatic hydrocarbons, PAHs, in particular) is closely related to climate change and climatic fluctuations, which are likely to influence contaminant’s transport pathways and transfer processes. Predicting how climate variability alters PAHs concentrations in the atmosphere still poses an exceptional challenge. In this sense, the main objective of this contribution is to assess the relationship between the North Atlantic Oscillation (NAO) index and the mean concentration of benzo[a]pyrene (BaP, the most studied PAH congener) in a domain covering Europe, with an emphasis on the effect of regional-scale processes. A numerical simulation for a present climate period of 30 years was performed using a regional chemistry transport model with a 25 km spatial resolution (horizontal), higher than those commonly applied. The results show an important seasonal behaviour, with a remarkable spatial pattern of difference between the north and the south of the domain. In winter, higher BaP ground levels are found during the NAO+ phase for the Mediterranean basin, while the spatial pattern of this feature (higher BaP levels during NAO+ phases) moves northwards in summer. These results show deviations up to and sometimes over 100% in the BaP mean concentrations, but statistically significant signals (p<0.1) of lower changes (20–40% variations in the signal) are found for the north of the domain in winter and for the south in summer.

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