Structure and Dynamics of the Gulf Stream's Interannual Migration East of Cape Hatteras
Notice bibliographique
Résumé
The Gulf Stream's (GS) main mode of interannual variability, its latitudinal migration, has been shown to be atmospherically forced by the North Atlantic Oscillation (NAO), taking a 2 year lag into account. Observational and model data were used here to examine the structure of the GS's migration and the dynamics linking it to atmospheric forcing. The structure of the GS's interannual variability was investigated from different measures of GS position and transport at 38°N and 27°N (i.e. the Florida Current). Using a zonally averaged index, the local measurements of GS position at 38°N proved good representations of overall meridional shifting of the current. GS position and transport were shown linked to the NAO, though the relationship between the GS and the Florida Current transport was not found statistically significant. This indicated that the Florida Current does not have a detectable interannual signal downstream in the GS. Further investigation of the link between GS position and the NAO revealed the GS position has a more robust correlation with the Icelandic Low (IL) component of the NAO rather than with the NAO itself. Using Sea Surface temperature composites, it was shown that for anomalously low (west) IL pressure (longitude) corresponding to cooler surface temperatures in the Labrador Sea the GS position shifts north after a period of ~2 years. The relationship between GS and IL pressure (longitude) was further used to create a forecasting scheme for GS position one year ahead of time. The correlation between the resulting forecasted GS and the observed GS was 0.60, significant at 95% level. Insight into the 2-year delay between the GS and atmospheric forcing was obtained from mean structure and interannual variability of the Slope Sea and Labrador Current. Observations suggested there is a statistically significant link between the Labrador Current, the Slope Sea, and GS position. On 0.5 to 1 year time scales, increases (decreases) in Slope Sea transport lags southward (northward) shifts in GS position by 1 year (r=0.48, significant at 95% level), and cooler (warmer) SSTs in the Slope Sea lead southward (northward) shifts in GS position by 0.5 years (r=0.65, significant at 95% level). On longer time scales, Labrador Current transport and GS position are found significantly correlated (r=-0.68, significant at 95% level) where increases in Labrador Current transport lead southern shifts in GS position taking a 2 year lag into account. Finally, the connection between GS position, the Atlantic meridional overturning circulation (AMOC) and the regional biogeochemical cycle was investigated using coupled climate models and ocean temperature observations. GS position and the AMOC simulated from GFDL's Climate Model 2.1 found enhanced (weakened) AMOC significantly correlated with south (north) shifts in GS position on decadal time scale. Similarly, results from the GFDL Earth System Models indicated an enhanced (weakened) AMOC leads southward (northward) displacements in GS position and increases (decreases) in regional chlorophyll and nutrient concentrations. | The Gulf Stream's (GS) main mode of interannual variability, its latitudinal migration, has been shown to be atmospherically forced by the North Atlantic Oscillation (NAO), taking a 2 year lag into account. Observational and model data were used here to examine the structure of the GS's migration and the dynamics linking it to atmospheric forcing. The structure of the GS's interannual variability was investigated from different measures of GS position and transport at 38°N and 27°N (i.e. the Florida Current). Using a zonally averaged index, the local measurements of GS position at 38°N proved good representations of overall meridional shifting of the current. GS position and transport were shown linked to the NAO, though the relationship between the GS and the Florida Current transport was not found statistically significant. This indicated that the Florida Current does not have a detectable interannual signal downstream in the GS. Further investigation of the link between GS position and the NAO revealed the GS position has a more robust correlation with the Icelandic Low (IL) component of the NAO rather than with the NAO itself. Using Sea Surface temperature composites, it was shown that for anomalously low (west) IL pressure (longitude) corresponding to cooler surface temperatures in the Labrador Sea the GS position shifts north after a period of ~2 years. The relationship between GS and IL pressure (longitude) was further used to create a forecasting scheme for GS position one year ahead of time. The correlation between the resulting forecasted GS and the observed GS was 0.60, significant at 95% level. Insight into the 2-year delay between the GS and atmospheric forcing was obtained from mean structure and interannual variability of the Slope Sea and Labrador Current. Observations suggested there is a statistically significant link between the Labrador Current, the Slope Sea, and GS position. On 0.5 to 1 year time scales, increases (decreases) in Slope Sea transport lags southward (northward) shifts in GS position by 1 year (r=0.48, significant at 95% level), and cooler (warmer) SSTs in the Slope Sea lead southward (northward) shifts in GS position by 0.5 years (r=0.65, significant at 95% level). On longer time scales, Labrador Current transport and GS position are found significantly correlated (r=-0.68, significant at 95% level) where increases in Labrador Current transport lead southern shifts in GS position taking a 2 year lag into account. Finally, the connection between GS position, the Atlantic meridional overturning circulation (AMOC) and the regional biogeochemical cycle was investigated using coupled climate models and ocean temperature observations. GS position and the AMOC simulated from GFDL's Climate Model 2.1 found enhanced (weakened) AMOC significantly correlated with south (north) shifts in GS position on decadal time scale. Similarly, results from the GFDL Earth System Models indicated an enhanced (weakened) AMOC leads southward (northward) displacements in GS position and increases (decreases) in regional chlorophyll and nutrient concentrations. | 113 pages
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule tête enseignante, pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».