PI: Dr. Spruce Schoenemann, University of Montana Western Environmental Sciences

Rocky Mountain snowpack over the recent 30-40 years has shown an unprecedented decline, yet extended observations of snowpack are few. Modern era satellite-derived estimates of snowcover provide valuable snowpack information for water resource managers, yet our understanding of how Rocky Mountain snowpack has responded during previous warm periods is incomplete. Quantitative isotope-based paleoclimate reconstructions, in conjunction with treering climate histories can provide critical information on the impact of past climate variability on mountain water storage. Tree-ring based 1 April Snow Water Equivalent (SWE) reconstructions in the Northern Rocky Mountains have extended the temporal history of snowpack changes to ~1200 A.D. In combination with carbonate isotope lake sediments, there is potential for extending winter season hydroclimate relationships through the Holocene epoch, providing a long-term record of snowpack and climate variability that integrates internal dynamics to orbitalscale forcings. Records will provide a unique insight on the mid-Holocene (~8−5 ka) climatic optimum when temperatures were analogous to the present-day, and will help anticipate snow derived water availability in a warmer future. Thus, the primary goals of this research are to:

  1. Produce a multi-millennial, winter-spring season paleoclimate reconstruction from tree ring and lake sediment isotope data for the Upper Missouri headwaters region in southwest Montana
  2. Use NASA MERRA reanalysis products to calibrate historical records with modern conditions
  3. Integrate historical records with instrumental data to anticipate future climate-snowpack isotope relationships.