大洋深部呼吸碳库的扩张与萎缩被认为导致大气pCO2在冰期的降低和冰消期（或间冰期）的升高，从而为大气pCO2的冰期旋回负责。因此，全面捕捉热带西太平洋深部呼吸碳库的演化是理解全球气候变化机制的绝佳切入点。然而，目前热带西太平洋深部呼吸碳库的研究局限于末次冰期，且只关注呼吸碳库的有无。项目以IODP 363航次钻取的站位U1490和U1486为材料，通过沉积物生源组分和氧化还原敏感元素、有孔虫Nd同位素和壳重反演热带西太平洋表层生产力、深部流通状况和深部[CO32-]。以此为基础，从热带西太平洋深部呼吸碳库的有无、强弱和组成，综合构建上新世以来其演化的长期趋势，精细解剖气候转型/突变期（上新世暖期、北半球大冰期、中更新世转型期和末次冰消期）其演化的细节过程。最后，将上新世以来热带西太平洋深部呼吸碳库的演化与大气pCO2记录对比，揭示两者的关联机制，明确热带西太平洋在过去全球气候变化中的地位。

Expansion and contraction of respired carbon reservoir in the deep ocean are hypothesized to result in glacial low values and deglacial (or interglacial) high values in atmospheric pCO2, thus contributing to glacial cycles in atmospheric pCO2. Accurately capturing the evolution of deep respired carbon reservoir in the tropical West Pacific is a valid chance to uncover the forcing of global climate changes. However, current research on deep respired carbon reservoir in the tropical West Pacific is constrained in the timescales of last glaciation, and just focusing on its (in)existence. Here, surface productivity, deep ventilation and deep [CO32-] in the tropical West Pacific since Pliocene are reconstructed by bulk biogenic components and redox-sensitive elements, and foraminiferal Nd and shell weight in the sites U1490 and U1486 from International Ocean Discovery Program (IODP) 363 expedition. Based on these data, from the perspective of (in)existence, intensity and composition of deep respired carbon reservoir in the tropical West Pacific, long-term trends on its evolution since Pliocene are integrated, and detailed processes on its evolution during the climate abrupt/transition periods such as Pliocene warm period, Northern Hemisphere glaciation, mid-Pleistocene transition and last deglaciation are subtly examined. Finally, the comparison of variations on deep respired carbon reservoir in the tropical West Pacific with glacial cycles in atmospheric pCO2 since Pliocene is used to reveal the mechanism on their correlations, thus confirming the significance of tropical West Pacific in the past global climate changes.