Related: Posts on El Ninos
One of four reconstructions in this study of El Nino amplitude from 1871-2008 shows no trend with global warming |
doi:10.1029/2012JC008031
Key Points
- No evidence of changes in El Nino frequency caused by global warming
- Absence of an unique mean location of La Nina
- El Nino in reanalysis correlates better with El Nino in ERSST
Department of Oceanography, Texas A&M University, College Station, Texas, USA
LOCEAN/IPSL, UPMC, Paris, France
Department of Oceanography, Texas A&M University, College Station, Texas, USA
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.
http://www.terradaily.com/reports/US_study_says_El_Nino_climate_change_link_fuzzy_999.html
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