Oceans and Global Change

海洋与全球变化 海洋在不到一年到数千年的时间尺度上引发、放大和调解全球气候变化。因此，了解海洋过去的变化对气候科学至关重要。事实上，古记录是我们对气候时间尺度的唯一观测约束。古海洋学旨在通过分析代用指标或示踪剂，即保存在沉积记录中的环境参数的可测量描述符，重建过去的海洋状况和动态，特别是在沉积作用长期持续的深海。我研究的首要目标是 描述、理解和量化沉积颗粒和示踪剂（如特定生物标志物或同位素）的分布; 建立它们与感兴趣的过程的机械关系，如洋流、海洋表面条件或海洋生物地球化学循环; 并确定其随时间的变化，特别侧重于末次冰期-间冰期循环。 指导我的研究和解决我们理解中的关键差距的具体长期问题是：海洋氮循环在多大程度上导致了大气CO2浓度的冰川-间冰期波动？热带太平洋过去是如何影响全球气候变化的？我们如何更好地量化过去的海面温度和盐度？ 越来越明显的是，了解过去的海洋和气候变异性是了解当今海洋/气候系统和模拟“人类世”期间未来潜在全球气候变化的关键，这一点已为专家科学家所接受。我的研究计划-与其他研究小组的国际合作-将继续贡献过去的海洋和气候变化的速度和幅度的关键限制。

Oceans and Global Change The ocean initiates, amplifies and mediates global climate change on time-scales ranging from less than a year to thousands of years. Understanding the ocean’s past variability is thus of paramount importance for climate science. Indeed, paleo-records are the only observational constraints we have on climate timescales. Paleoceanography aims to reconstruct past ocean conditions and dynamics through analysis of proxies or tracers, measurable descriptors of environmental parameters, which are preserved in the sedimentary record, especially in the deep ocean where sedimentation has been continuous for long periods. The overarching objective of my research is to describe, understand, and quantify the distribution of sedimentary particles and of tracers, such as specific biomarkers or isotopes; to establish their mechanistic relation to processes of interest, such as ocean currents, surface ocean conditions, or marine biogeochemical cycles; and to determine their variability through time, with a specific focus on the last glacial-interglacial cycle. Specific long-term questions that guide my research and address critical gaps in our understanding are: To what extent did the marine nitrogen cycle cause the glacial-interglacial swings in atmospheric CO2 concentrations? How did the tropical Pacific influence global climate change in the past? How can we better quantify past sea surface temperatures and salinities? It is becoming increasingly evident and accepted by expert scientists that understanding past ocean and climate variability is key to understanding the present-day ocean/climate system and for modelling potential future global climate change during the “Anthropocene”. My research program - in international collaboration with other research groups - will continue to contribute critical constraints on rates and amplitudes of past ocean and climate change.