Collaborative Research: P2C2 Cool and Warm Season Moisture Reconstruction and Modeling over North America

DESCRIPTION: The network of nearly 2,000 North American tree-ring chronologies is an outstanding high-resolution paleoclimate data set and has been used to reconstruct the long-term soil moisture balance across the continent. However, these existing reconstructions represent an average of the differing seasonal climate signals encoded in the annual ring width chronologies and do not provide discrete reconstructions of winter and summer conditions. The precise seasonality of ancient droughts and wet periods needs to be specified to provide the most realistic reconstructions of past climate and the most useful constraints for climate model simulations. Many North American tree-ring chronologies encode distinct seasonal climate signals that can be used for the separate reconstruction of cool and warm season moisture amounts over large sectors of the continent. The research will use hundreds of new and existing tree-ring chronologies to reconstruct both cool and warm season moisture levels across much of tropical, subtropical, and temperate North America. The seasonal reconstructions will be developed on a 0.5° grid for every year during two fixed time periods: AD 1500-present and AD 1000-present. They will be based on existing chronologies, re-measurements of existing tree-ring collections to derive seasonally explicit earlywood and latewood width chronologies, and selective field collections of new chronologies.