Ice sheet model-derived global mean sea level and whole ocean oxygen isotopes

Indian Ocean surface circulation is an important part of the global ocean conveyor belt, and is connected via two important gateways including the Indonesian Throughflow, and the Agulha Leakage. Changes in the surface hydrography of the Indian Ocean may therefore impact on the global overturning circulation. Using planktonic foraminifera-based reconstructions of Indian Ocean surface salinity and temperature, we find that Indian Ocean surface water salinify during glacial intensification. Here we present reconstructions of global mean sea level using the ice sheet model ANICE and benthic foraminifera oxygen isotope data from U1476 to analyse changes in mean global sea level and calculate whole ocean changes in seawater oxygen isotopes. We use this information to show that the Indian Ocean surface hydrography changed in different ways from other ocean basins during Late Pleistocene glacial-interglacial cycles.印度洋表层环流是全球海洋传送带（global ocean conveyor belt）的重要组成部分，通过印尼贯穿流（Indonesian Throughflow）与阿加勒斯泄漏（Agulha Leakage）两大关键通道与全球海洋系统连通。因此，印度洋表层水文环境的变化可能对全球翻转环流（global overturning circulation）产生影响。本研究依托基于浮游有孔虫（planktonic foraminifera）的印度洋表层盐度与温度重建序列，发现冰期强化阶段印度洋表层海水发生咸化。本研究利用冰盖模型ANICE以及U1476站位的底栖有孔虫（benthic foraminifera）氧同位素数据，重建了全球平均海平面序列，以此分析全球平均海平面变化，并计算了全球海水氧同位素的整体变化。基于上述分析结果，本研究表明，在晚更新世（Late Pleistocene）冰期-间冰期旋回过程中，印度洋表层水文环境的变化模式与其他大洋盆地存在显著差异。