The Indo-Pacific warm pool(IPWP) is crucial for regional and global climates. However, the development of the IPWP and its effect on the regional climate during the Cenozoic remain unclear. Here, using a compilation o...The Indo-Pacific warm pool(IPWP) is crucial for regional and global climates. However, the development of the IPWP and its effect on the regional climate during the Cenozoic remain unclear. Here, using a compilation of sea surface temperature(SST) records(mainly since the middle Miocene) and multimodel paleoclimate simulations, our results indicated that the extent, intensity and warmest temperature position of the IPWP changed markedly during the Cenozoic. Specifically, its extent decreased, its intensity weakened, and its warmest temperature position shifted from the Indian to western Pacific Ocean over time. The atmospheric CO_(2) dominated its extent and intensity, while paleogeography, by restricting the distribution of the Indian Ocean and the width of the tropical seaways, controlled the shift in its warmest temperature position. In particular, the eastward shift to the western Pacific Ocean from the middle to late Miocene inferred from compiled SST records likely resulted from the constriction of tropical seaways. Furthermore, by changing the atmospheric thermal structure and atmospheric circulation,the reduced extent and intensity of the IPWP decreased the annual precipitation in the western Indian Ocean, eastern Asia and Australia, while the shift in the warmest temperature position from the Indian to western Pacific Ocean promoted aridification in Australia. Qualitative model-data agreements are obtained for both the IPWP SST and regional climate. From the perspective of past warm climates with high concentrations of atmospheric CO_(2), the expansion and strengthening of the IPWP will occur in a warmer future and favor excessive precipitation in eastern Asia and Australia.展开更多
基金supported by the National Natural Science Foundation of China(41725010 and 42107472)the Strategic Priority Research Program of Chinese Academy of Sciences(XDB26000000 and XDB31000000)the Key Research Program of the Institute of Geology&Geophysics,Chinese Academy of Sciences(IGGCAS-201905)。
文摘上新世(5.33~2.58 Ma)是距今最近的大气CO_(2)浓度超过400 ppmv的暖期,是理解未来气候变化的地质历史相似型.地质记录显示,上新世气候主要响应地球倾角和岁差变化,比如深海氧同位素和高纬陆相记录表现出强的倾角周期(41 ka),低纬和地中海地区的粉尘和花粉记录以岁差周期(21 ka)为主.然而,这些气候周期空间差异的机制尚不清楚.我们使用全球海气耦合模式HadCM3,开展了轨道参数极值实验.结果表明:(1)倾角变化主要对高纬温度影响显著(>5℃),很好地解释了高纬记录和受高纬冰量调节的深海氧同位素记录的41 ka周期;(2)岁差变化主要影响低纬降水(>2 mm d-1),很好地解释了低纬和地中海地区与季风活动相关的21 ka气候周期.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB42000000)the Second Tibetan Plateau Scientific Expedition and Research Program (2019QZKK0101)the National Natural Science Foundation of China (42071113 and 42371166)。
文摘The Indo-Pacific warm pool(IPWP) is crucial for regional and global climates. However, the development of the IPWP and its effect on the regional climate during the Cenozoic remain unclear. Here, using a compilation of sea surface temperature(SST) records(mainly since the middle Miocene) and multimodel paleoclimate simulations, our results indicated that the extent, intensity and warmest temperature position of the IPWP changed markedly during the Cenozoic. Specifically, its extent decreased, its intensity weakened, and its warmest temperature position shifted from the Indian to western Pacific Ocean over time. The atmospheric CO_(2) dominated its extent and intensity, while paleogeography, by restricting the distribution of the Indian Ocean and the width of the tropical seaways, controlled the shift in its warmest temperature position. In particular, the eastward shift to the western Pacific Ocean from the middle to late Miocene inferred from compiled SST records likely resulted from the constriction of tropical seaways. Furthermore, by changing the atmospheric thermal structure and atmospheric circulation,the reduced extent and intensity of the IPWP decreased the annual precipitation in the western Indian Ocean, eastern Asia and Australia, while the shift in the warmest temperature position from the Indian to western Pacific Ocean promoted aridification in Australia. Qualitative model-data agreements are obtained for both the IPWP SST and regional climate. From the perspective of past warm climates with high concentrations of atmospheric CO_(2), the expansion and strengthening of the IPWP will occur in a warmer future and favor excessive precipitation in eastern Asia and Australia.
