Back to Search Start Over

Increased variability of eastern Pacific El Niño under greenhouse warming.

Authors :
Cai, Wenju
Wang, Guojian
Dewitte, Boris
Wu, Lixin
Santoso, Agus
Takahashi, Ken
Yang, Yun
Carréric, Aude
McPhaden, Michael J.
Source :
Nature; Dec2018, Vol. 564 Issue 7735, p201-206, 6p, 1 Chart, 9 Graphs, 3 Maps
Publication Year :
2018

Abstract

The El Niño-Southern Oscillation (ENSO) is the dominant and most consequential climate variation on Earth, and is characterized by warming of equatorial Pacific sea surface temperatures (SSTs) during the El Niño phase and cooling during the La Niña phase. ENSO events tend to have a centre—corresponding to the location of the maximum SST anomaly—in either the central equatorial Pacific (5° S-5° N, 160° E-150° W) or the eastern equatorial Pacific (5° S-5° N, 150°-90° W); these two distinct types of ENSO event are referred to as the CP-ENSO and EP-ENSO regimes, respectively. How the ENSO may change under future greenhouse warming is unknown, owing to a lack of inter-model agreement over the response of SSTs in the eastern equatorial Pacific to such warming. Here we find a robust increase in future EP-ENSO SST variability among CMIP5 climate models that simulate the two distinct ENSO regimes. We show that the EP-ENSO SST anomaly pattern and its centre differ greatly from one model to another, and therefore cannot be well represented by a single SST 'index' at the observed centre. However, although the locations of the anomaly centres differ in each model, we find a robust increase in SST variability at each anomaly centre across the majority of models considered. This increase in variability is largely due to greenhouse-warming-induced intensification of upper-ocean stratification in the equatorial Pacific, which enhances ocean-atmosphere coupling. An increase in SST variance implies an increase in the number of 'strong' EP-El Niño events (corresponding to large SST anomalies) and associated extreme weather events. Despite inter-model differences in predicting the details of the eastern Pacific El Niño, a robust increase in the corresponding sea surface temperature variability under greenhouse warming is found across models. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
00280836
Volume :
564
Issue :
7735
Database :
Complementary Index
Journal :
Nature
Publication Type :
Academic Journal
Accession number :
133531036
Full Text :
https://doi.org/10.1038/s41586-018-0776-9