  We construct a network from climate records of different geographical sites
in the North Atlantic. A link between two sites represents the
cross-correlations between the records of each site. We find that within the
different phases of the North Atlantic Oscillation (NAO) the correlation values
of the links are significantly different. By setting an optimize threshold on
the correlation values, we find that the number of strong links in the network
is increased during times of positive NAO indices, and decreased during times
of negative NAO indices. We find a pronounced sensitivity of the network
structure to the oscillations which is significantly higher compared to the
observed response of spatial average of the records. Our result suggests a new
measure that tracks the NAO pattern.
