Colloquium: Kevin Anchukaitis

The Asian Monsoon is a dominant feature of the global atmospheric circulation, controlling regional climate variability in south, southeast, and east Asia and influencing Africa and other more distal regions. Failure of the monsoon has potentially devastating consequences for the over one billion people that directly or indirectly depend on its rainfall for subsistence and for their economic well-being. Despite this, our understanding of the myriad influences on monsoon strength in the past and its likely behavior in the future remain tenuous at best. In this presentation, I explore the development and application of the Monsoon Asia Drought Atlas (MADA), a tree-ring based reconstruction of the spatiotemporal variability of the monsoon over the last millennium, which we can now use to establish an improved understanding of the low frequency and forced response of the system. Severe drought in the middle of the 14th century in Vietnam, India, and China occurred at the same time as drought conditions in North America, whereas a major 18th century megadrought is associated with more canonical pan-Pacific climate patterns. These and other extreme hydroclimate anomalies were also associated with significant human societal upheaval. I diagnose possible changes in atmosphere and ocean circulation collectively associated with large-scale, severe and persistent monsoon drought using independent proxy paleoclimate information developed from the region, as well as the results from a multimodel ensemble of millennial-length forced atmosphere-ocean general circulation model simulations.

Kevin Anchukaitis, Assistant Research Professor
Lamont-Doherty Earth Observatory, Columbia University