Rethinking the Ocean’s Role in the Southern Oscillation
The El Niño/La Niña-Southern Oscillation is a climatic pattern primarily characterized by warming and cooling of the tropical eastern Pacific Ocean over a period of two to five years. This pattern is linked with changes in climatic regimes worldwide. To understand the underlying mechanisms, DOE scientists have used atmospheric general circulation models (GCMs), which have varying degrees of coupling to the ocean, to examine the role of oceans in modulating the Southern Oscillation. Their results indicate that atmospheric GCMs coupled to simple ocean mixed layers can in fact reproduce the oscillation on a wide range of time scales ranging from interannual to decadal. When the atmospheric GCM is coupled to a full dynamical ocean, the amplitude of the interannual variability is strengthened, as are the global climatic changes correlated with the oscillation. This study leads the way in delineating the importance of understanding the underlying mechanisms of the El Niño Southern Oscillation, making it possible to develop improved climate predictions.
Clement, A. C., P. DiNezio, and C. Deser. 2011. “Rethinking the Ocean’s Role in the Southern Oscillation,” Journal of Climate, 24, 4056–4072. DOI: http://dx.doi.org/10.1175/2011JCLI3973.1.