What drives monsoon climate and droughts over East Asia and the Western Pacific Ocean?

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The East Asian monsoon (EAM) is a major component of the global climate system and vital to billions of people. What determines the strength of this system? New records of past variability of the monsoonal system are needed to contextualize predictions of future climate change. Critically, existing geological data provide conflicting evidence on the underlying driving mechanisms of floods and droughts, which are still debated. Geochemical records from caves in China reveal climate cycles paced at ~20 thousand-year intervals, suggesting EAM primarily responds to long-term changes in solar radiation, but other records suggest that greenhouse gas- and high-latitude ice sheet forcing are more important. An over-arching problem is a paucity of high-quality records that cover transitions between major climate states. This project will study marine sediment cores from regions sensitive to changes of climate conditions in East Asia, including the Japan Sea, the East China Sea, and the North Pacific Ocean. You will build and exploit long, well-dated, and high-resolution records of wind-blown dust from Asia and EAM variabilities. These records will cover key global climate states/transitions including the mid-Pleistocene transition, the late-Pliocene intensification of Northern Hemisphere glaciation, and warmer-than-present periods such as the mid-Pliocene and mid-Miocene.