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

点击翻译按钮获取中文摘要

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.