Trascasa Castro, P, Ruprich-Robert, Y, Castruccio, F et al. (1 more author) (2021) Warm phase of AMV damps ENSO through weakened thermocline feedback. Geophysical Research Letters, 48 (23). e2021GL096149. ISSN 0094-8276
Abstract
Interactions between ocean basins affect El Niño–Southern Oscillation (ENSO), altering its impacts on society. Here, we explore the effect of Atlantic Multidecadal Variability (AMV) on ENSO behavior using idealized experiments performed with the NCAR-CESM1 model. Comparing warm (AMV+) to cold (AMV−) AMV conditions, we find that ENSO sea surface temperature (SST) anomalies are reduced by ∼10% and ENSO precipitation anomalies are shifted to the west during El Niño and east during La Niña. Using the Bjerknes stability index, we attribute the reduction in ENSO variability to a weakened thermocline feedback in boreal autumn. In AMV+, the Walker circulation and trade winds strengthen over the tropical Pacific, increasing the background zonal SST gradient. The background changes shift ENSO anomalies westwards, with wind stress anomalies more confined to the west. We suggest the changes in ENSO-wind stress decrease the strength of the thermocline feedback in the east, eventually reducing ENSO growth rate.
Metadata
Item Type: | Article |
---|---|
Authors/Creators: |
|
Copyright, Publisher and Additional Information: | © 2021. The Authors. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. |
Dates: |
|
Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) > Inst for Climate & Atmos Science (ICAS) (Leeds) |
Funding Information: | Funder Grant number EU - European Union 820829 Leverhulme Trust PLP-2018-278 NERC (Natural Environment Research Council) NE/M018199/1 |
Depositing User: | Symplectic Publications |
Date Deposited: | 24 Nov 2021 14:37 |
Last Modified: | 15 Mar 2022 10:02 |
Status: | Published |
Publisher: | Wiley |
Identification Number: | 10.1029/2021GL096149 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:180740 |