Transition paths of North Atlantic Deep Water
We use Transition Path Theory (TPT) to infer statistically most effective equatorward routes of North Atlantic Deep Water (NADW) in the subpolar North Atlantic. Transition paths are ensembles of trajectory pieces flowing out from a source last and into a target next, i.e., they do not account for tr...
| Main Authors: | , , |
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| Format: | Article in Journal/Newspaper |
| Language: | unknown |
| Published: |
arXiv
2021
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| Subjects: | |
| Online Access: | https://dx.doi.org/10.48550/arxiv.2108.13771 https://arxiv.org/abs/2108.13771 |
| Summary: | We use Transition Path Theory (TPT) to infer statistically most effective equatorward routes of North Atlantic Deep Water (NADW) in the subpolar North Atlantic. Transition paths are ensembles of trajectory pieces flowing out from a source last and into a target next, i.e., they do not account for trajectory detours that unproductively contribute to transport. TPT is applied on all available RAFOS and Argo floats in the area by means of a discretization of the Lagrangian dynamics described by their trajectories. By considering floats at different depths, we investigate transition paths of NADW in its upper (UNADW) and lower (LNADW) layers. We find that the majority of UNADW transition paths sourced in the Labrador and southwestern Irminger Seas reach the western side of a target arranged zonally along the southern edge of the subpolar North Atlantic domain visited by the floats. This is accomplished in the form of a well-organized deep boundary current (DBC). LNADW transition paths sourced west of the Reykjanes Ridge reveal a similar pattern, while those sourced east of the ridge are found to hit the western side of the target via a DBC and also several other places along it in a less organized fashion. : Submitted to JPO; comments welcomed! |
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