Sea surface temperature reconstructions of sediment cores from the Atlantic sector of the Southern Ocean

Late Quaternary summer sea surface temperatures (SSTs) have been derived from radiolarian assemblages in the East Atlantic sector of the Southern Ocean. In the subantarctic and the polar frontal zone, glacial SSTs (oxygen isotope stages 2, 4, 6, and 8) were 3°-5°C cooler than today, indicating northward displacements of the isotherms about 2°-4° of latitudes. During interglacials, SSTs almost reached modern levels (oxygen isotope stages 7 and 9) or exceeded them by 2°-3°C (oxygen isotope stages 1 and 5.5). In the subantarctic Atlantic Ocean, changes in SST and calcium carbonate content of the sediment precede variations in global ice volume in the range of the main Milankovitch frequencies. Comparisons with the timing of North Atlantic Deep Water (NADW) proxy records suggests that this early response in the subantarctic Atlantic Ocean is not triggered by the flux of NADW to the Southern Ocean.

晚第四纪夏季海表温度（sea surface temperatures, SSTs）已通过南大洋东大西洋扇区的放射虫组合重建得到。在亚南极区与极锋带中，冰期海表温度（对应氧同位素阶段2、4、6及8）较现代偏低3℃至5℃，表明等温线向北偏移了约2°至4°纬度。间冰期期间，海表温度基本达到现代水平（对应氧同位素阶段7和9），或是较现代偏高2℃至3℃（对应氧同位素阶段1和5.5）。在亚南极大西洋海域，海表温度与沉积物碳酸钙含量的变化，在主要米兰科维奇周期频率范围内早于全球冰量变化出现。结合北大西洋深层水（North Atlantic Deep Water, NADW）代用指标记录的时间序列进行对比后可知，亚南极大西洋海域的这一早期响应并非由北大西洋深层水向南大洋的通量变化所触发。