Houghton Lectures

Gabriel Vecchi - Atmospheric Nonlinearity in El Nino
Date Time Location
October 15th, 2014 10:00am-11:00am MIT, 54-915
The El Niño-Southern Oscillation (ENSO) phenomenon is the largest mode of year-to-year variability in the climate system, involving large redistribution of rainfall and oceanic waters in the tropical Pacific and influencing weather and ecosystems throughout the globe. This lecture will discuss the character and mechanisms for ENSO, focusing principally on the role of the non-linear relationship between atmospheric convection and sea surface temperatures on the character of ENSO. Analysis of observations, as well as of conceptual and climate models, shows the role of atmospheric nonlinearity in El Niño onset and termination, key differences between moderate amplitude and extreme El Niño events, and aspects of the asymmetry between positive and negative phases of ENSO. Implications of these atmospheric nonlinearities for the prediction of El Niño and its impacts, and for understanding the response of El Niño to altered climates, will also be discussed.