ENSO Basics

Amy Clement [aclement@rsmas.miami.edu], Rosenstiel School of Marine and Atmospheric Sciences, University of Miami, FL.

This talk will provide an overview of the basic mechanisms of the El Nino/Southern Oscillation (ENSO) and its impacts around the globe. First, I will focus on the mechanism that is at the heart of ENSO: the Bjerknes feedback. As a result of this feedback, small perturbations to the equatorial surface temperature gradient can lead to substantial changes in the tropical Pacific climate, making this a possible key amplifying mechanism in the climate’s response to solar variability. The impacts of ENSO extend well beyond the tropical Pacific. I will briefly review the worldwide patterns of ENSO teleconnections, and then focus on the impacts of ENSO on precipitation over North America. I will conclude with a long-term perspective on ENSO that comes from paleoclimate records and climate models, which raises some important questions about how sensitive ENSO actually is to external forcing.