Department of Defense

Paleo-Southwest Monsoon Dynamics

Project Dates

This pilot project is not a core CLIMAS effort, but uses other funds to expand CLIMAS perspectives on the full range of climate variability that characterizes the Southwest. Little is known about the decade- to millennia-scale variations in the North American Monsoon and the response of this variability to changes in climate forcing. To help remedy this situation, the researchers are developing paleo-monsoon records using lake sediment and cave speleothems from sites in the southwestern United States and northern Mexico. In particular, this work examines the degree to which monsoon variations contributed to past climate extremes, including drought. Comparison between monsoon reconstructions and climate model results will help test hypothesized relationships between monsoon variability and sea surface temperature and other forcings. Work to date has focused primarily on the use of cave formations (“speleothems”) to reconstruct past climate variability. This work was funded as part of a NSF grant to UA Geoscience Professor Julie Cole. CLIMAS graduate student Truebe worked with CLIMAS PI Overpeck to investigate the use of lake sediments in NM and AZ (and Mexico – work completed with Science Foundation Arizona funding) to generate records that are complementary to the speleothem records. Multiple lakes have been visited, and our efforts to find lakes that are appropriate for this work continues.