Seasonal to interannual climate variability in the tropical southwest Pacific during the last deglaciation - Monthly resolved reconstructions from Great Barrier Reef corals

我建议通过分析大堡礁珊瑚的骨骼，重建热带西南太平洋上一次冰川消融期间的季节性和年际气候变化范围。这些珊瑚将由IODP 325(2010年2月)进行，这是一次由欧洲海洋研究钻探联合会(ECORD)进行的针对特定任务的平台考察。对化石珊瑚中锶/钙和氧同位素比值的分析将提供几十年时间窗内海面温度和水文平衡的月度分辨率重建，有力地解析年度周期。这些珊瑚记录将首次能够量化热带西南太平洋在20,000至10,000年前发生的季节性和年际气候变化的幅度变化。此外，该项目可以在不同于今天的边界条件下，对年际时间尺度上的大气-海洋变化的自然模式的动态提供独特的见解，例如厄尔尼诺-南方涛动，可能还有印度洋偶极子。将这种基于珊瑚的超高分辨率最后一次去冰川气候变化的快照与最先进的气候模型模拟进行比较，将有助于评估未来温室气体预测在与社会相关的时间尺度上的有效性。建议的项目涉及IODP考察队325的一个主要科学目标。

I suggest reconstructing the range of seasonality and interannual climate variability during the last deglaciation in the tropical southwest Pacific Ocean, by analysing the skeletons of annually-banded corals from the Great Barrier Reef. The corals will be recovered by IODP Expedition 325 (February 2010), a Mission Specific Platform Expedition conducted by the European Consortium for Ocean Research Drilling (ECORD). The analyses of Sr/Ca and oxygen isotope ratios in fossil corals will provide monthly resolved reconstructions of temperature and hydrologic balance at the sea surface for time windows of several decades, robustly resolving the annual cycle. These coral records, for the first time, will allow quantifying changes in the amplitude of seasonality and interannual climate variability in the tropical southwest Pacific that occurred from 20,000 to 10,000 years ago. Furthermore, the project can provide unique insights into the dynamics of natural modes of atmosphere-ocean variability on interannual timescales, such as the El Niño-Southern Oscillation and possibly the Indian Ocean Dipole, under boundary conditions different from today. Comparing such ultrahigh-resolution coral-based snapshots of last deglacial climate variability with state-ofthe- art climate model simulations will help to assess the validity of future greenhouse projections on timescales relevant for society. The suggested project addresses a major scientific objective of IODP Expedition 325.