P2C2: Northern and Southern Low-Latitude Precipitation Histories--Testing Ideas about Millennial and Orbital-Scale Climate Change

University Of Minnesota-Twin Cities, Minneapolis MN

Investigators

Abstract

This research team seeks to extend absolute-dated records of the oxygen isotopic composition of speleothem calcite from the Northern Hemisphere (southeast Asia) and from Southern Hemisphere (South America) low latitude sites. For each of these regions, the investigators aim to: (i) extend the records deeper in time; (ii) broaden the geographic coverage within the region; (iii) increase the oxygen isotope resolution within key time ranges; and (iv) apply newly developed dating techniques to refine and extend chronologies. For the northern site, the team plans to extend the record an additional three glacial-interglacial cycles back to about 650,000 years ago and also establish a record in the mid-Quaternary (1.3 to 1.5 million years ago). For the southern site, the researchers seek to develop a record covering the last few glacial-interglacial cycles. With these new records, the principal investigators will test hypotheses related to: (1) the causes of millennial-scale climate change; (2) the causes of ice age terminations; (3) the mechanisms for long-term monsoon variability; and (4) the controls on the oxygen isotopic composition of rainfall in regions affected by monsoon rainfall. A better understanding of the temporal and spatial variability of precipitation over low latitude sites would be of great scientific value to the wider science community. Through this project, the researchers will continue to develop strong international collaborations with Chinese and Brazilian scientist. The project also supports a post-doctoral scholar.