Internal wave propagation in the Arctic Ocean
Notice bibliographique
Résumé
The propagation of internal gravity waves in the Arctic Ocean is studied using direct and indirect observations, reanalysis data and two numerical models. I focus on how stratification modifies wave propagation and its connection to the pathways of internal wave energy from the surface to the deep ocean. Understanding internal wave propagation in the Arctic Ocean is crucial for better understanding wave-driven mixing and its implications for climate projections. Therefore, three specific aspects of internal wave propagation have been addressed in this thesis. First, the transient transmission of a wave packet across a density staircase is studied using a 2D Boussinesq model. A series of simulations with fixed wave frequency and varying horizontal wave number are carried out. The results show that the incident wave excites trapped modes by a near resonance mechanism, which slowly transfer energy above and below the staircase. A theoretical prediction was made using typical values for thermohaline staircases and internal waves in the Arctic Ocean. Surface-generated near-inertial internal waves that excite trapped modes should have a critical horizontal wavelength of ∼ 400 m. For higher-frequency non-hydrostatic waves, this critical horizontal wavelength decreases to ∼ 80 m. Such waves are likely to be generated by wind-driven ice floes. Secondly, the existence of turning depths for near-inertial internal waves and their effect on wind-driven deep mixing is assessed using 10 years of temperature and salinity profiles in the Canadian Basin. It is found that turning depths exist in the deep Canadian Basin at ∼ 2750 m, but with decreasing distance from the bottom towards the slope. A subsequent discussion focuses on the possible topographic interaction of internal wave reflection and dissipation, especially where turning depths are shallow and above the slope, where the evanescent perturbation of the internal waves can still interact with the topography. Finally, direct observations of near-inertial internal waves are investigated using current observations from a mooring on the Gakkel Ridge, and their surface generation is addressed using a wind and ice drift speed and ice concentration dataset. Cross correlation analysis shows that there is a correlation between ice drift speed and near inertial wave energy with a lag of < 26 days. In addition, a correlation of ∼ 15 days is observed between the wind factor and the near-inertial wave energy. This result suggests that near-inertial internal waves may be generated at the surface by an interplay of wind and ice properties and propagate from the surface to the seafloor. Evidence for wave reflection is also found, and 2D numerical simulations of waves reflected at a turning depth are performed and compared with observations, showing qualitative agreement.
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 machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,001 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,001 |
| Études des sciences et des technologies | 0,001 | 0,000 |
| Communication savante | 0,001 | 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 source (Gemma direct ou Codex distillé), 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 ».