Summer sea surface temperatures calculated from radiolaria at ODP Site 177-1089 in the subantarctic Atlantic

A submillennial resolution, radiolarian-based record of summer sea surface temperature (SST) documents the last five glacial to interglacial transitions at the subtropical front, southern Atlantic Ocean. Rapid fluctuations occur both during glacial and interglacial intervals, and sudden cooling episodes at glacial terminations are recurrent. Surface hydrography and global ice volume proxies from the same core suggest that summer SST increases prior to terminations lead global ice-volume decreases by 4.7 ± 3.7 ka (in the eccentricity band), 6.9 ± 2.5 ka (obliquity), and 2.7 ± 0.9 ka (precession). A comparison between SST and benthic delta13C suggests a decoupling in the response of northern subantarctic surface, intermediate, and deep water masses to cold events in the North Atlantic. The matching features between our SST record and the one from core MD97-2120 (southwest Pacific) suggests that the super-regional expression of climatic events is substantially affected by a single climatic agent: the Subtropical Front, amplifier and vehicle for the transfer of climatic change. The direct correlation between warmer DeltaTsite at Vostok and warmer SST at ODP Site 1089 suggests that warmer oceanic/atmospheric conditions imply a more southward placed frontal system, weaker gradients, and therefore stronger Agulhas input to the Atlantic Ocean.

本数据集以放射虫为代用指标，具备亚千年分辨率，记录了南大西洋亚热带锋区末次五次冰期-间冰期旋回的夏季海表温度（SST）变化。冰期与间冰期时段均存在快速气候波动，且冰消期的突发性降温事件反复出现。
对同一岩芯获取的表层水文学参数与全球冰量代用指标的分析显示，在偏心率周期带中，夏季海表温度在冰消期前的升温较全球冰量下降提前4.7±3.7千年；在斜度周期带中提前6.9±2.5千年；在岁差周期带中提前2.7±0.9千年。
对比海表温度与底栖δ¹³C的记录发现，南次极洋区表层、中层与深层水团对北大西洋冷事件的响应存在解耦现象。
本海表温度记录与西南太平洋MD97-212岩芯的相关记录高度匹配，表明气候事件的超区域表现特征主要受单一气候因子调控：亚热带锋区作为气候变化传递的放大器与载体，对其具有实质性影响。
沃斯托克（Vostok）冰芯的升温ΔT_site与大洋钻探计划（ODP）1089站位的海表温度升高存在直接相关性，这表明海洋与大气的暖期状态对应着锋面系统更偏南、经向温度梯度更弱，因此阿古拉斯洋流向大西洋的输入强度更高。