Julien Emile-geay

El Niã±o and the Earth's Climate: from Decades to Ice Ages Julien Emile-geay

The dominant paradigm of paleoclimatology holds thatfluctuations in the oceans' meridional overturningcirculation can explain most past climate changes. There is, however, acute recognition of theimportance of tropical Pacific sea-surfacetemperatures in orchestrating modern climatevariability on timescales longer than a few years, epitomized by the El Niño - Southern Oscillationphenomenon (ENSO). This book investigates a subset ofmechanisms whereby low-frequency variability isproduced within the tropical Pacific and exported tothe rest of the globe. We first develop an analyticaltheory of decadal changes in the tropical Pacific, making the case that local air/sea interactions canaccount for the observed variability. Next we use amodel of intermediate complexity to explore theresponse of the ENSO system to changes volcanic andsolar forcing over the Holocene. In both cases weconfront our model predictions to the paleoclimaterecord. We close by a study of ENSO teleconnectionsduring the last Ice Age. This work is aimed atscholars and graduate students in climatologyinterested in theories of tropically-driven climatechange, with equal emphasis on models and data.