  The temperatures in different zones in the world do not show significant
changes due to El-Nino except when measured in a restricted area in the Pacific
Ocean. We find, in contrast, that the dynamics of a climate network based on
the same temperature records in various geographical zones in the world is
significantly influenced by El-Nino. During El-Nino many links of the network
are broken, and the number of surviving links comprises a specific and
sensitive measure for El-Nino events. While during non El-Nino periods these
links which represent correlations between temperatures in different sites are
more stable, fast fluctuations of the correlations observed during El-Nino
periods cause the links to break.
