Published by the American Geophysical Union as part of the Geophysical Monograph Series, Volume 189. Climate Dynamics: Why Does Climate Vary? presents the major climate phenomena within the climate system to underscore the potency of dynamics in giving rise to climate change and variability. These phenomena include deep convection over the Indo-Pacific warm pool and its planetary-scale organization: the Madden-Julian Oscillation, the monsoons, the El Nino-Southern Oscillation, the Pacific Decadal Oscillation, and the low-frequency variability of extratropical circulations. The volume also has a chapter focusing on the discussion of the causes of the recent melting of Arctic sea ice and a chapter devoted to the discussion of the causes of recent changes in the frequency and intensity of tropical cyclones. On each topic, the basic material of climate dynamics is covered to aid the understanding of the forefront research, making the volume accessible to a broad spectrum of readers.The volume highlights include * Diabatic and nonlinear aspects of the El Nino-Southern Oscillation * Causes of sea ice melting in the Arctic * Impact of global warming on tropical cyclone activity * Origins of the Pacific Decadal Oscillation * Causes of climate variability of Asian monsoonsThe volume will be of particular interest to graduate students and young researchers in atmospheric and oceanic sciences and related disciplines such as geology and geography. The book will also be a good read for those who have a more general interest in the Earth's climate and why it varies.