Collaborative Research: Evolution of the Climate Continuum - Late Paleogene to Present

确定气候变化背后的驱动力，以及地球气候系统对这些驱动力的敏感性，是古气候研究中的一个中心问题。这项研究将首次明确评估与晚古近纪至新近纪气候系统(36 Ma至今)的演化有关的随机气候过程与确定性气候过程的变化。之所以选择这个时间框架，是因为有高质量、高分辨率、连续的数据可供分析，而且这段时间间隔跨越了从高二氧化碳“温室”气候向低二氧化碳“冰屋”气候的过渡。研究人员专注于分析已公布的有孔虫的氧和碳同位素记录，并使用了许多植根于汤姆森多锥光谱法(MTM)的技术，以及一套非线性时间序列分析方法。该项目将产生几个产品：1)新的高分辨率海底d18O综合记录，跨越36 Ma到现在，2)分析同一时间框架内轨道信号的演变，3)量化古近纪晚期至新近纪期间随机气候变率的变化，以及通过温室-冰屋气候转变评估确定性轨道相对于随机气候能量的相对优势。资金支持年轻的PI和一名资深女科学家之间的合作，以及研究生培训。在研究过程中产生的算法将作为更广泛的气候科学界的资源公开提供。

Determining the driving forces behind climate change, as well as the sensitivity of Earth's climate system to these forces, is a central question in paleoclimate research. This study will provide the first explicit evaluation of changes in stochastic versus deterministic climate processes associated with the evolution of the Late Paleogene to Neogene climate system (36 Ma to the present). This timeframe was chosen because high quality, high resolution, continuous data are available for analysis, and because the interval spans the transition from a high pCO2 "Greenhouse" climate to a low pCO2 "Icehouse" world. The investigators focus on the analysis of published foraminiferal oxygen and carbon isotope records and use a number of techniques rooted in Thomson's multi-taper spectral method (MTM), as well as a suite of non-linear time series analysis methods. The project will generate several products: 1) a new high resolution benthic d18O composite record spanning 36 Ma to the present, 2) an analysis of the evolution of orbital signals over the same timeframe, and 3) a quantification of changes in stochastic climate variability during the Late Paleogene to Neogene, and an assessment of the relative dominance of deterministic orbital versus stochastic climate energy through the Greenhouse-Icehouse climate transition. Funding supports collaboration between a young PI and a senior female scientist, as well as graduate student training. The algorithms produced in the course of the research will be made publicly available as a resource for the broader climate science community.