Observed change and the extent of coherence in the Gulf Stream system

By transporting warm and salty water poleward, the Gulf Stream system maintains a mild climate in northwestern Europe while also facilitating the dense water formation that feeds the deep ocean. The sensitivity of North Atlantic circulation to future greenhouse gas emissions seen in climate models h...

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Bibliographic Details
Main Authors: Asbjørnsen, Helene, Eldevik, Tor, Skrefsrud, Johanne, Johnson, Helen L., Sanchez-Franks, Alejandra
Format: Article in Journal/Newspaper
Language:English
Published: Copernicus Publications 2023
Subjects:
Online Access:https://doi.org/10.5194/egusphere-2023-2963
https://noa.gwlb.de/receive/cop_mods_00070387
https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00068736/egusphere-2023-2963.pdf
https://egusphere.copernicus.org/preprints/2023/egusphere-2023-2963/egusphere-2023-2963.pdf
Description
Summary:By transporting warm and salty water poleward, the Gulf Stream system maintains a mild climate in northwestern Europe while also facilitating the dense water formation that feeds the deep ocean. The sensitivity of North Atlantic circulation to future greenhouse gas emissions seen in climate models has prompted an increasing effort to monitor the various ocean circulation components in recent decades. Here, we synthesise available ocean transport measurements from several observational programs in the North Atlantic and Nordic Seas, as well as an ocean state estimate (ECCOv4-r4), for an enhanced understanding of the Gulf Stream and its poleward extensions as an interconnected circulation system. We see limited coherence between the records on interannual time scales, highlighting the local oceanic response to atmospheric circulation patterns and variable recirculation time scales within the gyres. On decadal time scales, we find a weakening subtropical circulation between the mid-2000s and mid-2010s, while the inflow and circulation in the Nordic Seas remained stable. Differing decadal trends in the subtropics, subpolar North Atlantic, and Nordic Seas warrant caution in using observational records at a single latitude to infer large-scale circulation change.