The Association of the Evolution of Intraseasonal Oscillations to ENSO Phase

Paul E. Roundy, Joseph R. Kravitz
2009 Journal of Climate  
Prior studies have given conflicting results about the role of atmospheric intraseasonal variations in the development of the El Niño/Southern Oscillation (ENSO). The Pacific Ocean intraseasonal Kelvin wave is a leading oceanic mode that may link intraseasonal tropical atmospheric variations with interannual variations in the coupled ocean-atmosphere system. This study considers the premise that if atmospheric and oceanic intraseasonal modes interact and evolve differently during various stages
more » ... ring various stages of ENSO, this result may provide useful information with regard to the role of these intraseasonal processes in ENSO evolution. This work utilizes signals of the oceanic Kelvin wave as a statistical basis for a simple composite averaging technique that is applied during different phases of ENSO to objectively analyze the evolution of oceanic and atmospheric intraseasonal oscillations. Results suggest that the Madden-Julian Oscillation and other atmospheric modes act and interact with oceanic Kelvin waves to evolve differently during different phases of ENSO. The structures of the different patterns suggest the possibility that systematic changes in the evolution of intraseasonal variations over the course of ENSO might feedback upon this interannual mode to influence the evolution of ENSO itself.
doi:10.1175/2008jcli2389.1 fatcat:3gv2uv3i5jgjbme2hqmr7udhvm