Structural evolution of the Tropical Pacific climate network

A new methodology based on information theory is used to explore the evolution of the surface air temperature climate network over the Tropical Pacific region. Topological changes over the period 1948–2009 are investigated using windows of one year duration. Alternating states of lower/higher efficiency in information transfer are consistently captured during the opposing phases of ENSO (i.e., El Niño and La Niña years). This cyclic information transfer behavior reflects a higher climatic stability for La Niña years which is in good agreement with current observations. In addition, after the 1976/77 climate shift, a change towards more frequent conditions of decreased information transfer efficiency is detected. Copyright EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg 2012