Abstract East China Sea (ECS) is greatly influenced by East Asian Summer Monsoon (EASM), precipitation discharge and differential inflow of the warm and saline Kuroshio Current (KC). Any change in surface water conditions either due to variations in ocean currents or discharge from terrestrial rivers have pronounced effects on the population abundance of planktic foraminifera; therefore, planktic foraminifera happen to be a valuable proxy to decipher paleoceanographic changes in the ECS. To understand the influence of KC and EASM at ECS, paleoceanographic changes are reconstructed for the last 400 kyr using planktic foraminiferal population abundances and Mg/Ca ratio derived Sea Surface Temperature (SST) from IODP site U1429. Nine different species/species associations of planktic foraminifera are found to be significant at this site. Q-mode factor analysis of these abundant species helped to retain four factors explaining ~91% of the data variance suggesting four different conditions prevailing at ECS over the last 400 kyr. The species association of factor 1 reflects cold surface water conditions in the ECS, factor 2 suggests the influence of the coastal water, factor 3 can be linked with the upwelling of lower thermocline water, and factor 4 is strongly associated with the strength of the KC. This study suggests that KC and EASM were stronger during the interglacial periods. The proxy that responds to KC strength (Globogerinoides ruber) and calculated Mg/Ca SST shows the presence of 23 kyr precession and 100 kyr eccentricity cycles modulated by the differential inflow of KC due to global and local factors. The comparison of SST of the western Pacific with SST of the ECS shows that KC actively transports heat to ECS from the equatorial western Pacific warm pool.

中文翻译：

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使用浮游有孔虫重建的最后~400 kyr 期间东海古海洋学变化

摘要 东海（ECS）受东亚夏季风（EASM）、降水流量和暖咸黑潮（KC）差异流入的影响很大。由于洋流的变化或陆地河流的排放，地表水条件的任何变化都会对浮游有孔虫的种群数量产生显着影响；因此，浮游有孔虫恰好是破译 ECS 中古海洋学变化的有价值的代表。为了了解 KC 和 EASM 在 ECS 的影响，使用浮游有孔虫种群丰度和来自 IODP 站点 U1429 的海表温度 (SST) 的 Mg/Ca 比值重建了过去 400 kyr 的古海洋学变化。发现浮游有孔虫的九个不同物种/物种协会在该地点具有重要意义。对这些丰富物种的 Q 模式因子分析有助于保留四个因子，解释约 91% 的数据方差，表明在过去的 400 kyr 中 ECS 存在四种不同的条件。因子 1 的物种关联反映了 ECS 中寒冷的地表水条件，因子 2 表明沿海水的影响，因子 3 可能与较低温跃层水的上涌有关，因子 4 与 KC 的强度密切相关. 这项研究表明，KC 和 EASM 在间冰期更强。响应 KC 强度（Globogerinoides ruber）和计算的 Mg/Ca SST 的代理显示存在 23 kyr 进动和 100 kyr 偏心率循环，由 KC 的差异流入由于全局和局部因素而调制。