10² to 10³ year scale variability of the El Niño/Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD) in the eastern Indian Ocean over the last 30,000 years

最近的研究一致认为，印度尼西亚群岛在现在和过去的全球气候中扮演着关键角色。然而，在重建区域气候及其对全球的影响时，特别是在百年到千年的时间尺度上以及在气候突变期间，基于代理的结果和模拟结果都不同。这些研究强调，有必要从东印度洋西南部和西南部的印度尼西亚群岛获得迄今缺失的高分辨率替代证据，该区域是热带气候动态的一个关键区域，特别是在印度洋偶极子和厄尔尼诺-南方涛动方面。在印度尼西亚西部和西南部的高分辨率沉积岩心中使用浮游有孔虫的地球化学指标，我们的目标是重建受IOD/ENSO事件强烈影响的区域水文的过去变化。我们将解释这些结果，以便在上述时间尺度上重建IOD的过去强度及其与ENSO的联系。尽管最近在理解ENSO和IOD的年际方面取得了进展，但到目前为止，它们的长期运作及其与全球气候的联系的基本特征仍然难以捉摸。我们的研究将为这些现象在不同气候状态和边界条件下的长期行为提供线索。

Recent studies agree that the Indonesian Archipelago plays a key role in present and past global climate. However, both proxy-based and modelling results differ when reconstructing the regional climate and its global implications, particularly on centennial to millennial timescales and during abrupt climate changes. These studies underline the need for hitherto missing high-resolution proxy evidence from the eastern Indian Ocean W and SW of the Indonesian Archipelago, a key region in tropical climate dynamics especially with regard to the Indian Ocean Dipole (IOD) and El Niño-Southern Oscillation (ENSO). Using planktonic foraminifera-based geochemical proxies in high-resolution sediment cores from off W- and SW-Indonesia, we aim to reconstruct past variations in the regional hydrography that is strongly affected by IOD/ENSO events. We will interpret these results in order to reconstruct past intensity of the IOD and its link to ENSO on the above mentioned time-scales. Despite recent progress in understanding the inter-annual aspects of ENSO and IOD, the basic characteristics of their long-term operation and their link to global climate are so far elusive. Our study will provide clues on the long-term behavior of these phenomena under different climate states and boundary conditions.