Department of Geology, State University of New York at Buffalo, Buffalo, NY 14260
Department of Geology, State University of New York at Buffalo, Buffalo, NY 14260.
Proc Natl Acad Sci U S A. 2021 May 18;118(20). doi: 10.1073/pnas.2022916118.
The relative warmth of mid-to-late Pleistocene interglacials on Greenland has remained unknown, leading to debates about the regional climate forcing that caused past retreat of the Greenland Ice Sheet (GrIS). We analyze the hydrogen isotopic composition of terrestrial biomarkers in Labrador Sea sediments through interglacials of the past 600,000 y to infer millennial-scale summer warmth on southern Greenland. Here, we reconstruct exceptionally warm summers in Marine Isotope Stage (MIS) 5e, concurrent with strong Northern Hemisphere summer insolation. In contrast, "superinterglacial" MIS11 demonstrated only moderate warmth, sustained throughout a prolonged interval of elevated atmospheric carbon dioxide. Strong inferred GrIS retreat during MIS11 relative to MIS5e suggests an indirect relationship between maximum summer temperature and cumulative interglacial mass loss, indicating strong GrIS sensitivity to duration of regional warmth and elevated atmospheric carbon dioxide.
格陵兰中更新世晚期间冰期的相对温暖程度一直未知，这导致了关于导致过去格陵兰冰盖（GrIS）退缩的区域气候强迫的争论。我们通过过去 600,000 年的间冰期分析拉布拉多海沉积物中的陆地生物标志物的氢同位素组成，以推断格陵兰南部千年尺度夏季的温暖程度。在这里，我们重建了在海洋同位素阶段 (MIS) 5e 期间异常温暖的夏季，与强的北半球夏季太阳辐射同时发生。相比之下，“超级间冰期”MIS11 仅表现出适度的温暖，在长时间的高二氧化碳大气持续存在。与 MIS5e 相比，MIS11 期间强烈推断的 GrIS 退缩表明夏季最高温度与累积间冰期质量损失之间存在间接关系，这表明 GrIS 对区域温暖和高二氧化碳大气持续时间的敏感性很强。
