Non-linearity in the pathway of El Niño-Southern Oscillation to the tropical North Atlantic
El Niño-Southern Oscillation can influence the Tropical North Atlantic (TNA), leading to anomalous sea surface temperatures (SST) at a lag of several months. Several mechanisms have been proposed to explain this teleconnection. These mechanisms include both tropical and extratropical pathways, contr...
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ftethz:oai:www.research-collection.ethz.ch:20.500.11850/489136 2023-12-10T09:51:15+01:00 Non-linearity in the pathway of El Niño-Southern Oscillation to the tropical North Atlantic Casselman, Jake W. Taschetto, Andréa S. Domeisen, Daniela id_orcid:0 000-0002-1463-929X 2021-09-01 application/application/pdf https://hdl.handle.net/20.500.11850/489136 https://doi.org/10.3929/ethz-b-000489136 en eng American Meteorological Society info:eu-repo/semantics/altIdentifier/doi/10.1175/jcli-d-20-0952.1 info:eu-repo/semantics/altIdentifier/wos/000752587000019 info:eu-repo/grantAgreement/SNF/SNF-Förderungsprofessuren Stufe 2/170523 http://hdl.handle.net/20.500.11850/489136 doi:10.3929/ethz-b-000489136 info:eu-repo/semantics/openAccess http://rightsstatements.org/page/InC-NC/1.0/ In Copyright - Non-Commercial Use Permitted Journal of Climate, 34 (17) Dynamics ENSO Teleconnections Tropical variability info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 2021 ftethz https://doi.org/20.500.11850/48913610.3929/ethz-b-00048913610.1175/jcli-d-20-0952.1 2023-11-13T00:51:16Z El Niño-Southern Oscillation can influence the Tropical North Atlantic (TNA), leading to anomalous sea surface temperatures (SST) at a lag of several months. Several mechanisms have been proposed to explain this teleconnection. These mechanisms include both tropical and extratropical pathways, contributing to anomalous trade winds and static stability over the TNA region. The TNA SST response to ENSO has been suggested to be nonlinear. Yet the overall linearity of the ENSO-TNA teleconnection via the two pathways remains unclear. Here we use reanalysis data to confirm that the SST anomaly (SSTA) in the TNA is nonlinear with respect to the strength of the SST forcing in the tropical Pacific, as further increases in El Niño magnitudes cease to create further increases of the TNA SSTA. We further show that the tropical pathway is more linear than the extratropical pathway by sub-dividing the inter-basin connection into extratropical and tropical pathways. This is confirmed by a climate model participating in the CMIP5. The extratropical pathway is modulated by the North Atlantic Oscillation (NAO) and the location of the SSTA in the Pacific, but this modulation insufficiently explains the nonlinearity in TNA SSTA. As neither extratropical nor tropical pathways can explain the nonlinearity, this suggests that external factors are at play. Further analysis shows that the TNA SSTA is highly influenced by the preconditioning of the tropical Atlantic SST. This preconditioning is found to be associated with the NAO through SST-tripole patterns. ISSN:0894-8755 ISSN:1520-0442 Article in Journal/Newspaper North Atlantic North Atlantic oscillation ETH Zürich Research Collection Pacific |
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Open Polar |
collection |
ETH Zürich Research Collection |
op_collection_id |
ftethz |
language |
English |
topic |
Dynamics ENSO Teleconnections Tropical variability |
spellingShingle |
Dynamics ENSO Teleconnections Tropical variability Casselman, Jake W. Taschetto, Andréa S. Domeisen, Daniela id_orcid:0 000-0002-1463-929X Non-linearity in the pathway of El Niño-Southern Oscillation to the tropical North Atlantic |
topic_facet |
Dynamics ENSO Teleconnections Tropical variability |
description |
El Niño-Southern Oscillation can influence the Tropical North Atlantic (TNA), leading to anomalous sea surface temperatures (SST) at a lag of several months. Several mechanisms have been proposed to explain this teleconnection. These mechanisms include both tropical and extratropical pathways, contributing to anomalous trade winds and static stability over the TNA region. The TNA SST response to ENSO has been suggested to be nonlinear. Yet the overall linearity of the ENSO-TNA teleconnection via the two pathways remains unclear. Here we use reanalysis data to confirm that the SST anomaly (SSTA) in the TNA is nonlinear with respect to the strength of the SST forcing in the tropical Pacific, as further increases in El Niño magnitudes cease to create further increases of the TNA SSTA. We further show that the tropical pathway is more linear than the extratropical pathway by sub-dividing the inter-basin connection into extratropical and tropical pathways. This is confirmed by a climate model participating in the CMIP5. The extratropical pathway is modulated by the North Atlantic Oscillation (NAO) and the location of the SSTA in the Pacific, but this modulation insufficiently explains the nonlinearity in TNA SSTA. As neither extratropical nor tropical pathways can explain the nonlinearity, this suggests that external factors are at play. Further analysis shows that the TNA SSTA is highly influenced by the preconditioning of the tropical Atlantic SST. This preconditioning is found to be associated with the NAO through SST-tripole patterns. ISSN:0894-8755 ISSN:1520-0442 |
format |
Article in Journal/Newspaper |
author |
Casselman, Jake W. Taschetto, Andréa S. Domeisen, Daniela id_orcid:0 000-0002-1463-929X |
author_facet |
Casselman, Jake W. Taschetto, Andréa S. Domeisen, Daniela id_orcid:0 000-0002-1463-929X |
author_sort |
Casselman, Jake W. |
title |
Non-linearity in the pathway of El Niño-Southern Oscillation to the tropical North Atlantic |
title_short |
Non-linearity in the pathway of El Niño-Southern Oscillation to the tropical North Atlantic |
title_full |
Non-linearity in the pathway of El Niño-Southern Oscillation to the tropical North Atlantic |
title_fullStr |
Non-linearity in the pathway of El Niño-Southern Oscillation to the tropical North Atlantic |
title_full_unstemmed |
Non-linearity in the pathway of El Niño-Southern Oscillation to the tropical North Atlantic |
title_sort |
non-linearity in the pathway of el niño-southern oscillation to the tropical north atlantic |
publisher |
American Meteorological Society |
publishDate |
2021 |
url |
https://hdl.handle.net/20.500.11850/489136 https://doi.org/10.3929/ethz-b-000489136 |
geographic |
Pacific |
geographic_facet |
Pacific |
genre |
North Atlantic North Atlantic oscillation |
genre_facet |
North Atlantic North Atlantic oscillation |
op_source |
Journal of Climate, 34 (17) |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1175/jcli-d-20-0952.1 info:eu-repo/semantics/altIdentifier/wos/000752587000019 info:eu-repo/grantAgreement/SNF/SNF-Förderungsprofessuren Stufe 2/170523 http://hdl.handle.net/20.500.11850/489136 doi:10.3929/ethz-b-000489136 |
op_rights |
info:eu-repo/semantics/openAccess http://rightsstatements.org/page/InC-NC/1.0/ In Copyright - Non-Commercial Use Permitted |
op_doi |
https://doi.org/20.500.11850/48913610.3929/ethz-b-00048913610.1175/jcli-d-20-0952.1 |
_version_ |
1784896719280930816 |