ABSTRACT

The Asian monsoon system directly affects the lives of more than half of humanity worldwide. Yet, the dynamical processes that govern its complex spatiotemporal variability are not well enough understood to model and predict its behavior, due in part to inadequate long-term climate observations over most of Asia. To rectify this deficiency, we have developed seasonally resolved spatial reconstructions of Asian monsoon drought and wetness over the past millennium from a network of long tree-ring chronologies. This ‘Monsoon Asia Drought Atlas’ (MADA) provides the spatiotemporal details of known historic monsoon failures and reveals the occurrence of previously unknown monsoon megadroughts in ways never before possible. The MADA thus provides a long-term context for recent Asian monsoon variability that is critically needed for climate modeling, prediction, and attribution studies.