High Resolution Absolute-dated Histories of Northern and Southern Low Latitude Precipitation: Links between Low and High Latitude Climate over Glacial-Interglacial Cycles

该项目利用资金获取北半球（中国东部）和南半球（巴西东部）低纬度地区洞穴方解石氧同位素组成的高分辨率、绝对年代记录。由于长度和分辨率的结合，这些记录可能能够解决长时间、高分辨率冰芯记录（如格陵兰和南极序列）所解决的各种问题。总的来说，这项研究将为更好地理解高纬度和低纬度气候与南半球和北半球气候之间的联系提供新的数据，从而对气候变化机制（例如海洋和大气环流变化、高纬度与热带触发、北方与南方触发、轨道强迫和太阳强迫）施加限制。该研究正在解决的一些具体科学问题是：(1)格陵兰岛的观测结果在时间和空间上与地球上其他地方的气候有何关系？(2)在格陵兰记录的范围之外，进一步回溯到更早的冰期、去冰期和间冰期，这些更早时期的气候在多大程度上与最近的类似物相似或不同？(3)这些高纬度站点的降水氧同位素组成历史与相应的低纬度降水氧同位素组成历史之间的关系如何？研究人员已经与中国和巴西的科学同事建立了合作伙伴关系，他们将帮助收集、分析和解释来自不同洞穴遗址的大量洞穴样本。用于这项研究的资金利用了联邦、国际和私人来源的支持。

This project uses funds to obtain high-resolution, absolute-dated records of the oxygen isotopic composition of speleothem calcite from Northern Hemisphere (eastern China) and Southern Hemisphere (eastern Brazil) low latitude sites. Due to the combination of length and resolution, such records may be able to address the kinds of questions that have been addressed by long, high-resolution ice core records, such as the Greenland and Antarctic sequences. In general, the research will provide new data to better understanding of connections between high and low latitude climate and Southern and Northern Hemisphere climate, thereby placing constraints on climate change mechanisms (e.g. oceanic and atmospheric circulation change, high northern latitude versus tropical triggers, northern versus southern triggers, orbital forcing, and solar forcing). Some specific science issues being addressed with the research are: (1) How do the Greenland observations relate, temporally and spatially, to climate elsewhere on Earth? (2) Looking further back in time beyond the limit of the Greenland records to earlier glacial periods, deglacial intervals and interglacial periods, to what extent was climate in these earlier periods similar to or different from their most recent analogues? (3) How does the history of the oxygen isotopic composition of meteoric precipitation at these high-latitude sites relate to the corresponding history of oxygen isotopic composition of precipitation at low-latitudes? The investigators have built up collaborative partnerships with Chinese and Brazilian science colleagues who will help collect, analyze, and interpret samples from a large suite of speleothem samples from varying cave sites. The funds used for this research leverage federal, international, and private sources of support.