Structural evolution of the tropical pacific climate network

Abstract

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.