The Tropospheric Pathway of the ENSO–North Atlantic Teleconnection
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UNIL restricted access
State: Public
Version: Final published version
License: Not specified
Serval ID
serval:BIB_DCFFD76F3C75
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
The Tropospheric Pathway of the ENSO–North Atlantic Teleconnection
Journal
Journal of Climate
ISSN
0894-8755
1520-0442
1520-0442
Publication state
Published
Issued date
01/06/2018
Peer-reviewed
Oui
Volume
31
Number
11
Pages
4563-4584
Language
english
Abstract
El Niño–Southern Oscillation (ENSO) exerts an influence on the North Atlantic–European (NAE) region. However, this teleconnection is nonlinear and nonstationary owing to the superposition and interaction of a multitude of influences on this region. The stratosphere is one of the major players in terms of the influence of the ENSO signal on this sector. Nevertheless, there are tropospheric dynamical links between the North Pacific and the North Atlantic that are clearly influenced by ENSO. This tropospheric pathway of ENSO to the NAE has received less attention. In view of this, the present study revisits the tropospheric pathway of ENSO to the North Atlantic using ECMWF reanalysis products. Anomalous propagation of transient and quasi-stationary waves across North America is analyzed with respect to their sensitivity to ENSO. Transient (quasi-stationary zonal waves 1–3) wave activity flux (WAF) from the Pacific to the Atlantic increases during El Niño (La Niña) conditions leading to a negative (positive) phase of the North Atlantic Oscillation (NAO). This response is observed from January to March for El Niño and only visible during February for La Niña events. However, the stratosphere strongly modulates this response. For El Niño (La Niña) conditions a weaker (stronger) stratospheric vortex tends to reinforce the negative (positive) NAO with the stratosphere and troposphere working in tandem, contributing to a stronger and more persistent tropospheric circulation response. These findings may have consequences for the prediction of the NAO during times with an inactive stratosphere.
Keywords
ENSO, Rossby waves, Teleconnections, North Atlantic Oscillation, Stratosphere
Web of science
Publisher's website
Funding(s)
Swiss National Science Foundation / PP00P2_170523
Create date
08/03/2022 14:13
Last modification date
14/11/2024 13:56