NOAA/WDS Paleoclimatology - Upper Snake River 415 Year Streamflow Reconstructions

STUDY NOTES: Wise 2010 tree-ring reconstruction of streamflow at three gages in the upper Snake River. Reconstruction is of total annual (water year) flow in acre-feet. The reconstructed gage records are for the following gages: (1) Jackson Lake at Dam on Snake River near Moran, WY: 43.8575N,-110.59W, 2065M (2) south fork of the Snake River at Palisades Dam, ID: 43.3327N, -111.2025W, 1708M (3) Snake River near Heise, ID: 43.6419N, -111.6844W, 1525M Reconstruction is based on 3 tree-ring chronologies: FMT Douglas fir (S. Gray): 42.96°N, 109.77°W, 2300m, 1507-2006AD HRI Limber pine (Teton Science School): 43.30°N, 110.67°W, 2000m 1505-2006AD RDH Limber pine (E. Wise): 43.62°N, 110.44°W, 2300m, 1322-2006AD The RDH chronology is archived in the International Tree Ring Data Bank (ITRDB): http://www.ncdc.noaa.gov/paleo/treering.html Instrumental data was supplied by the U.S. Bureau of Reclamation (http://www.usbr.gov/pn/hydromet). See Wise (2010) for more complete description of data and methods.
ABSTRACT SUPPLIED BY ORIGINATOR: Tree ring samples collected near the Snake River headwaters were augmented with preexisting tree ring chronologies to create a 415 year reconstruction of upper Snake River streamflow, extending the short instrumental record and providing the first description of multicentury water supply variability in this river. Results indicate that the region's early 21st century drought is severe even in the context of long-term climatic variability and that the instrumental record is representative of low-flow individual years. In terms of overall magnitude, droughts of the recent past are eclipsed by a sustained low-flow period lasting for over 30 years in the early to mid-1600s. A comparison of reconstructed Snake River flow with streamflow reconstructions of the Colorado, Sacramento, and Verde rivers suggests that changes in the predominance of zonal versus meridional atmospheric flow may have influenced drought patterns in the western United States through time.