Recent studies suggest that, interannual, decadal, and quasibidecadal periodicities dominate global sea surface temperature and sea level pressure variability over past hundred years. In this study, we present evidence that the quasibidecadal mode of variability can be considered in a first order approximation as resulting from a linear interaction between the dominant modes of variability in the Tropical Pacific (associated with interannual variability) and North Atlantic ocean (associated with decadal variability). A two coupled delayed action oscillators model is proposed to qualitatively explain this result. ¿ 2001 American Geophysical Union