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

季风系统是亚洲大部分地区环境状况的主要决定因素，因此影响着地球上人口最稠密的地区。了解季风在最近的地质历史中是如何演变的，对于预测它在未来可能发生的变化至关重要，例如在气候变化，特别是全球变暖的影响下。全新世夏季风强度变化的代用证据大多来自于位于印度和东亚季风区的大陆和海洋档案。迄今为止，人们对晚全新世印尼-澳大利亚季风的发展知之甚少。本项目拟在几十年至百年的时间尺度上研究印尼-澳大利亚季风（IAM），以验证以下假设：(a)距今3000年后的夏季IAM减弱；(b)全新世中期至晚全新世期间IAM及其北半球对应的异步发展。为此，将对从NW Sumba岛（印度尼西亚）外的龙目岛东部海域回收的两个沉积物岩心进行浮游有孔虫动物群组合和Mg/ cabbased海面温度（SST）的分析。两个岩心均位于松巴岛西北外海现代夏季风引起的上升流区，被认为是过去上升流强度变化的非常敏感的档案，是夏季IAM活动的记录者。

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.