A climate network-based index to discriminate different types of El Niño and La Niña

Author(s): M. Wiedermann, A. Radebach, J.F. Donges, J. Kurths, and R.V. Donner
In: Geophysical Research Letters 43
Year: 2016
Type: Journal / article
Theme affiliation: Complex Adaptive Systems, Landscapes
Full reference: M. Wiedermann, A. Radebach, J.F. Donges, J. Kurths, and R.V. Donner. 2016. A climate network-based index to discriminate different types of El Niño and La Niña, Geophysical Research Letters 43

Summary

El Niño exhibits distinct Eastern Pacific (EP) and Central Pacific (CP) types which are commonly, but not always consistently, distinguished from each other by different signatures in equatorial climate variability. Here we propose an index based on evolving climate networks to objectively discriminate between both flavors by utilizing a scalar-valued measure that quantifies spatial localization and dispersion in global teleconnections of surface air temperature. Our index displays a sharp peak (high localization) during EP events, whereas during CP events (larger dispersion) it remains close to the values observed during normal periods. In contrast to previous classification schemes, our approach specifically accounts for El Niño's global impacts. We confirm recent El Niño classifications for the years 1951 to 2014 and assign types to those cases where former works yielded ambiguous results. Ultimately, we demonstrate that our index provides a similar discrimination of La Niña episodes into two distinct types.

Share

Stockholm Resilience Centre is a collaboration between Stockholm University and the Beijer Institute of Ecological Economics at the Royal Swedish Academy of Sciences

Stockholm Resilience Centre
Stockholm University, Kräftriket 2B
SE-10691
Phone: +46 8 674 70 70
info@stockholmresilience.su.se

Organisation number: 202100-3062
VAT No: SE202100306201