TRACKING CHANGES IN INDIAN SUMMER MONSOON INTENSITY USING PRECIPITATION AND LAKE LEVEL PROXIES FROM EASTERN TIBET

More than 40% of the world’s population is reliant on water from the Asian monsoons, particularly the Indian Summer Monsoon (ISM), the primary source of growing season precipitation for the southeastern Tibetan Plateau and surrounding area. Paleolimnological records, from lakes in particular, provide vital archives of trends in precipitation and lake levels that allow for assessment of monsoon intensity and changes over time. For this ongoing study, we are compiling a transect of sediment cores and surface sediments from Southeastern Tibetan lakes to assess paleo-precipitation and lake level changes during the Holocene. Multi-proxy analysis of these sediments includes sedimentology, grain sizes, terrestrial leaf wax isotopes, and diatom community assemblage analysis. The primary emphasis of this project is to demonstrate how ISM precipitation varied both temporally and spatially across the study area and its relationship with other modes of variability in the global climate system. Records from this study show strong agreement with existing ISM paleoclimate records from regional caves, lakes, and bogs, but yield additional insight into rainfall trends during the Holocene. This project and similar reconstructions furthers our understanding of wet versus dry conditions under monsoon systems and can be utilized for constraining climate models to best capture natural variability.