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.
