Recent analyses (Garreaud and Battisti, 1999; Deser, 2002) indicate that the roots of Pacific decadal variability may lie in the tropical Indian/western Pacific oceans and south Pacific convergence zone. Support for this suggestion is being sought in the results of a 1000-yr integration with the CCCma coupled ocean-atmosphere model.

The principal mode of tropical decadal-interdecadal Pacific variability for the CGCM shows reasonably realistic features compared to the corresponding observation-based mode. Upper-ocean temperatures, atmospheric circulation, and energy balance at the air-sea interface are examined to explore the mechanisms involved in generating and maintaining the mode. The role of off-equatorial Rossby waves, the physical processes controlling the air-sea interaction, and the associated atmosphere/ocean patterns that result are also analyzed.