Multi-decadal to centennial-scale development of the Indonesian-Australian summer monsoon over the last 6,000 years

点击翻译按钮获取中文摘要

The monsoon system is the main determinant of environmental conditions over much of Asia, and so affects the most densely populated region on Earth. Understanding how the monsoon has evolved in the recent geologic past is crucial to predictions of how it may change in the future, for example under the influence of climate change, especially global warming. Most proxy evidence on multi-decadal to centennial scale changes in summer monsoon intensity during the Holocene has been deduced from continental and marine archives located in the Indian and East Asian monsoon domains. Up to now, very little is known about the development of the Indonesian-Australian monsoon during the Late Holocene. This project intends to investigate the Indonesian-Australian monsoon (IAM) on multi-decadal to centennial time-scales in order to test hypotheses about (a) a summer IAM weakening after 3,000 years before present and (b) an asynchronous development of the IAM and its northern hemisphere counterparts during the Middle to Late Holocene. To this end, two sediment cores recovered from the eastern Lombok Basin off NW Sumba Island (Indonesia) will be analysed for planktonic foraminiferal faunal assemblage and Mg/Cabased sea surface temperatures (SST). Located in the modern summer monsoon induced upwelling area off NW Sumba Island, both cores are considered as very sensitive archives of past changes in upwelling intensity as a recorder of the summer IAM activity.