The Indo‐Pacific Warm Pool (IPWP) is home to the warmest sea surface temperatures in the world oceans, favoring strong tropospheric convection and heavy rainfall. The mechanisms controlling long‐term change in the region's hydroclimate are still uncertain. Here, we present a 450,000‐year record of precipitation δD from southern Sumatra that records a consistent pattern of glacial isotopic enrichment and interglacial depletion. We synthesize existing paleo‐indicators of precipitation δD and δ¹⁸O in the IPWP and compare results with water isotope‐enabled climate simulations of the Last Glacial Maximum (LGM). The simulations show glacial isotopic enrichment over the eastern Indian Ocean extending into the southern IPWP and isotopic depletion over Southeast Asia, the west Pacific, and Australia. The pattern of simulated LGM isotopic change agrees generally well with our proxy synthesis. We conclude that reorganization of regional circulation under glacial conditions controls precipitation isotope variability in the IPWP: Low‐level tropospheric convergence dominates the signal in the north/east, whereas divergence controls the response in the south/west. Additional sensitivity simulations suggest that the LGM ice sheets and the associated lowering in sea level, rather than decreased greenhouse gases, are responsible for the distinctive spatial pattern in glacial changes of precipitation isotopes and hydroclimate across the IPWP.

中文翻译：

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揭示印度太平洋暖池中的冰川水文气候：水同位素的观点

印度太平洋暖池（IPWP）是世界海洋最温暖的海面温度的发源地，有利于强对流层对流和强降雨。控制该地区水文气候长期变化的机制仍然不确定。在这里，我们呈现了苏门答腊南部地区450,000年的降水δD记录，记录了冰同位素富集和冰间耗竭的一致模式。我们综合现有降水δD的古指标和δ ¹⁸在IPWP中输入O，然后将结果与基于水同位素的“最后冰期最大值”（LGM）的气候模拟进行比较。模拟表明，印度洋东部的冰川同位素富集一直延伸到南部IPWP，而东南亚，西太平洋和澳大利亚的同位素耗尽。模拟的LGM同位素变化的模式与我们的代理合成大体上一致。我们得出的结论是，冰川条件下区域环流的重组控制了IPWP中的降水同位素变异性：低空对流层辐合控制着北/东的信号，而发散控制了南/西的响应。其他敏感性模拟表明，LGM冰盖和相关的海平面下降，而不是温室气体减少，