Historical changes in El Niño and La Niña characteristics in an ocean reanalysis
Article first published online: 8 NOV 2012
©2012. American Geophysical Union. All Rights Reserved.
Journal of Geophysical Research: Oceans (1978–2012)
Volume 117, Issue C11, November 2012
How to Cite
2012), Historical changes in El Niño and La Niña characteristics in an ocean reanalysis, J. Geophys. Res., 117, C11007, doi:10.1029/2012JC008031., and (
- Issue published online: 8 NOV 2012
- Article first published online: 8 NOV 2012
- Manuscript Accepted: 19 SEP 2012
- Manuscript Revised: 17 SEP 2012
- Manuscript Received: 14 MAR 2012
- El Niño;
- climate variability;
- tropical Pacific
 The variation of El Niño Southern Oscillation (ENSO) events from the mid-nineteenth century until the beginning of the twenty-first century is explored using an ocean reanalysis. A comparison of the reanalysis with three sea surface temperature reconstructions shows that the timing of events is similar in all four products, however there are important differences in the strength and location of events. The difference between the reconstructions is sometimes larger than the difference between the reanalysis and a given reconstruction. These differences are larger in the first half of the record, a period for which there are relatively sparse observations. The reanalysis is used to explore decadal variability and trends in the frequency, duration, and propagation direction of ENSO events. There is considerable decadal variability of these ENSO characteristics with the time between events ranging from several months to ten years and the duration of ENSO varying from 5 to 27 months. As has been previously shown for the strength and location of ENSO there is little overall trend in the characteristics. Having a three dimensional representation of the ocean from the reanalysis allows exploration of subsurface changes during ENSO. An analysis of subsurface anomalies shows that during ENSO events the subsurface anomalies are highly correlated with the strength of surface anomalies over the 140 year period. Overall, there is no evidence that there are changes in the strength, frequency, duration, location or direction of propagation of El Niño and La Niña anomalies caused by global warming during the period from 1871 to 2008.