Funding is provided to investigate the behavior of the North American Monsoon (NAM) as a critical source of moisture for northwestern Mexico and the U.S. Southwest. Specifically, the researchers will design and apply new techniques to develop a tree-ring network that targets long-term NAM variability in the US Southwest.
The researchers will use partial-width indices (earlywood and latewood) from this network, combined with stable-carbon isotope measurements from tree rings, to reconstruct and examine the long-term variability of monsoon season precipitation, its relation with winter precipitation and widespread droughts in western North America, and to ocean/atmosphere circulation in the Pacific Ocean. The tree-ring data will also be combined with downscaled general circulation model (GCM) simulations to help understand the spatial and temporal characteristics of the NAM in the southwestern U.S. over the last few centuries as a means of providing a baseline for assessing both the instrumental records and the skill of downscaled GCMs in replicating natural variability.
The broader impacts involve a strong educational mentoring portion and an equally strong intellectual portion. The research will help support graduate and undergraduate student involvement in a cutting-edge paleoclimate project whose goal is to use tree-rings science to better inform regional water resource planners.
