Central eastern China hydrological changes and ENSO-like variability over the past 1800 yr

Abstract Variations in East Asian summer monsoon (EASM) precipitation impact agriculture, water resources, electricity generation, and economic development in the densely populated region of central eastern China. However, uncertainties remain in the history and driving mechanisms of precipitation changes in this region over the past two millennia. We present an 1800 yr multiproxy reconstruction of monsoon precipitation based on hydroclimate variations inferred from Lake Nvshan sediments in the Jiang-Huai region of central eastern China. We find that rainfall in the Jiang-Huai region was higher during the Little Ice Age (LIA) than during the Medieval Warm Period (MWP), and that these changes were modulated by the mean state of the tropical Pacific Ocean on centennial time scales. We infer that an El Niño–like (La Niña–like) mean state caused a strengthening and westward displacement (weakening and eastward displacement) of the Western Pacific Subtropical High (WPSH) and a weakening (strengthening) of the EASM, causing more (less) rainfall in the Jiang-Huai region during the LIA (MWP). These hydroclimate changes are likely to have been a response to changes in effective radiative forcing.