SIOPACT - Developing a ~250 year climate record for the Southeastern Indian Ocean sector of the Indo-PACific warm pool and its global climate Teleconnections

东印度洋和印度洋-太平洋暖池是全球气候系统的热机，也是环热带/温带降雨/干旱变率的重要参与者，缺乏来自东印度洋和印度洋-太平洋暖池的长期仪器气候记录，是减少基于模式的气候变化过程研究中的不确定性和成功规划未来变暖世界的主要问题。我们建议在印度-太平洋暖池的东南印度洋部分的关键地点开发新的~250年的、绝对年代和季节分辨的海面温度和盐度重建，其时间和空间覆盖范围前所未有。这将有助于填补目前印度洋-太平洋暖池中最大的海洋气候数据缺口，这对全球气候变化和环印度洋社会至关重要。为了实现这一目标，我们的项目将从长寿的大型珊瑚中开发地球化学记录，这些记录可用于量化过去海温和盐度的波动。该项目的结果将为印度-太平洋暖池过去和现在的行为及其与印度洋和热带太平洋气候现象的相互作用提供关键的环境和气候基线，例如印度洋变暖、厄尔尼诺Niño-Southern涛动和（多）年代际变率。最后，我们将验证以下假设：1)海洋热浪的时空发生和印度洋-太平洋暖池在澳大利亚西北部印度洋东南部珊瑚礁的最终扩张与El Niño、La Niña和ENSO中性年受太平洋年代际变率调制的西太平洋温度梯度的明显海洋和大气强迫有关。2)热带印度洋变暖是年际和年代际气候异常的独立起搏器。3)东南印度洋海温和暖池的扩张对热带气候异常和驱动南亚热带和温带地区的热浪和干旱/降雨变率至关重要。

Lack of long instrumental climate records from the eastern Indian Ocean and Indo-Pacific warm pool, the heat engine of the global climate system and an essential player in circum-tropical/extratropical rainfall/drought variability, is the main problem for reducing uncertainties in model-based climate change process studies and to successfully plan for a future warmer world. We propose to develop new ~250 year long, absolutely dated and seasonally-resolved reconstructions of sea surface temperature and salinity with unprecedented temporal and spatial coverage from key sites in the southeastern Indian Ocean sector of the Indo-Pacific warm pool. These will help to close the biggest current marine climate data gap in the Indo-Pacific warm pool that is of paramount importance to global climate variability and to circum-Indian Ocean societies. Towards this aim our project will develop geochemical records from long-lived massive corals that can be used to quantify past fluctuations of SST and salinity. Outcomes of this project will produce critical environmental and climatic baselines on past and current behavior of the Indo-Pacific warm pool and its interaction with Indian Ocean and tropical Pacific climate phenomena over more than two centuries, e.g. Indian Ocean warming, El Niño-Southern Oscillation and (multi)decadal variability. Ultimately, we will test the following hypothesis: 1) The spatio-temporal occurrence of marine heat waves and the ultimate expansion of the Indo-Pacific warm pool at the southeastern Indian Ocean reefs off northwest Australia is related to distinct oceanic and atmospheric forcing by the western Pacific temperature gradient during El Niño, La Niña and ENSO neutral years modulated by Pacific decadal variability. 2) Tropical Indian Ocean warming is an independent pacemaker of interannual and decadal climate anomalies. 3) SST in the southeastern Indian Ocean and the expansion of the warm pool is of paramount importance for tropical climate anomalies and in driving heat waves and drough/rainfall variability across the Austral-Asian tropics and extratropics.