Development and application of geochemical tracers for paleo and modern oceanography

人为二氧化碳的增加可能会改变未来的气候，我们必须提高我们的预测能力，以决定最佳的社会反应。海洋通过控制大气中的二氧化碳和重新分配入射的太阳热量，在调节地球气候方面发挥着关键作用。海水中两种天然放射性同位素（230Th和231Pa）的分布提供了现代海洋粒子动力学、碳通量和深水环流的重要信息，可用于更好地量化对气候变化具有重要意义的海洋过程。此外，将这些同位素纳入沉积记录提供了一种评估这些海洋过程与过去气候变化相关的时间演变的手段，并提供了区分人为活动引起的气候趋势和反复出现的自然循环所需的时间背景。

The rise in anthropogenic CO2 may alter future climate and we must improve our predictive capabilities to decide on optimal societal responses. The ocean plays a critical role in regulating Earth's climate by controlling atmospheric CO2 and by redistributing incoming solar heat. The distribution of two natural radioisotopes (230Th and 231Pa) in seawater provides important information on particle dynamics, carbon fluxes and deep-water circulation in the modern ocean, which can be used to better quantify oceanic processes important for climate change. In addition, the incorporation of these isotopes in the sedimentary record provides a means of assessing the temporal evolution of these oceanic processes in relation to past climate changes and provides the needed temporal context to distinguish between climatic trends induced by anthropogenic activities and recurring natural cycles.