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、放大和调节全球气候变化。因此，了解海洋过去的变化对气候科学至关重要。事实上，古记录是我们在气候时间尺度上唯一的观测限制。古海洋学旨在通过分析沉积记录中保存的代用物或示踪剂（可测量的环境参数描述符）来重建过去的海洋条件和动力学，特别是在沉积已连续很长时间的深海中。我研究的首要目标是描述、理解和量化沉积颗粒和示踪剂的分布，如特定的生物标志物或同位素；***建立它们与感兴趣的过程的机制关系，如洋流、海洋表面条件或海洋生物地球化学循环；并确定它们随时间的变化，特别关注末次冰期-间冰期旋回。***指导我的研究和解决我们理解中的关键空白的具体长期问题是：海洋氮循环在多大程度上导致了大气二氧化碳浓度的冰期-间冰期波动？热带太平洋在过去是如何影响全球气候变化的？我们怎样才能更好地量化过去的海面温度和盐度？***了解过去的海洋和气候变率是了解当今海洋/气候系统和模拟“人类世”期间潜在的未来全球气候变化的关键，这一点越来越明显，并为专家科学家所接受。我的研究项目——与其他研究小组进行国际合作——将继续对过去海洋和气候变化的速度和幅度做出关键的限制。**

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. **