Upper Klamath River Basin 1000 Year Precipitation Reconstructions Malevich, S.B.; Woodhouse, C.A.; Meko, D.M. Malevich, S.B. Woodhouse, C.A. Meko, D.M. Precipitation Reconstruction hydrology precipitation earth science/paleoclimate/climate reconstructions|tree ring (age,null,null,year Common Era,null,climate reconstructions|tree ring,null,null,N,null) earth science/paleoclimate/climate reconstructions|tree ring (precipitation,null,null,centimeter,Oct-Sep,climate reconstructions|tree ring,null,null,N,3 chronology predictors) earth science/paleoclimate/climate reconstructions|tree ring (precipitation,null,null,centimeter,Oct-Sep,climate reconstructions|tree ring,null,null,N,17 chronology predictors) earth science/paleoclimate/instrumental (precipitation,null,null,centimeter,Oct-Sep,instrumental,null,null,N,null) earth science/paleoclimate/reconstructions (Klamath Falls>LATITUDE 42.2008>LONGITUDE -121.7814) This work presents the first tree-ring reconstructions of hydroclimate for the Upper Klamath River basin, which stretches from northern California into southern Oregon. The extended record provides a centuries-long perspective on the region’s hydroclimatic variability and context for water-related political issues that have erupted in recent years. Reconstructions of water-year precipitation for Klamath Falls, Oregon (extending 1564-2004 and 1000-2010 CE) were developed to compare past drought severity with drought severity of the instrumental record (extending 1896-2011). The reconstructions suggest that variability exhibited during the instrumental period captures extremes of moderate-to-long-duration (6-, 10-, and 20-year) droughts, but not of short (single-year and 3-year) and very long (50-year) droughts, which were more severe during the 11th-13th centuries. The late-16th-century “mega drought” is present in the Klamath River basin, though with less strength than in the neighboring Sacramento River basin. Cool-season storm tracks appear to be a direct driver of hydroclimatic variability, leading to instances of see-saw like relationships with neighboring regions, such as in the mid-14th century. In contrast, the larger area of drought in the 12th century is suggestive of a long-term northward shift in cool-season storm tracks. STUDY NOTES: Updated reconstructed water year (WY; October-September) Klamath Falls precipitation (cm yr^-1). The reconstructions archived here are updated versions of those used in Malevich et al. 2013. (There were some weakly dated series that were unintentionally included in the original - the resulting changes are minor). Klamath Falls, Oregon water-year precipitation is adopted as a proxy for Upper Klamath basin streamflow and hydroclimate. Klamath Falls precipitation was reconstructed using stepwise multiple linear regression. Two models were created. One model, "kfalls1", was trained using the entire available pool of chronology predictors, whose common time period is 1600-2003. A second model, "kfalls2", was trained with three chronologies whose common period is 1000-2010. In this manner, one model emphasizes predictive performance (larger and presumably more robust predictor set) while the other model emphasizes length of reconstruction. Updated tree ring chronologies utilized in this study are included in the International Tree Ring Data Bank (ITRDB): http://www.ncdc.noaa.gov/data-access/paleoclimatology-data/datasets/tree-ring The ITRDB codes are CA674-CA679 and OR092-OR095. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Malevich, S.B. Investigator : Woodhouse, C.A. Investigator : Meko, D.M. 2013-09-13 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/15070 https://www1.ncdc.noaa.gov/pub/data/paleo/treering/reconstructions/northamerica/usa/klamath2013precip.txt https://www1.ncdc.noaa.gov/pub/data/paleo/treering/reconstructions/northamerica/usa/klamath2013precip.txt English https://www.ncdc.noaa.gov/paleo/study/15070 https://www1.ncdc.noaa.gov/pub/data/paleo/treering/reconstructions/northamerica/usa/klamath2013precip.txt Steven B. Malevich, Connie A. Woodhouse, and David M. Meko. 2013. Tree-ring reconstructed hydroclimate of the Upper Klamath basin. Journal of Hydrology, Vol. 495, pp. 13-22, 12 July 2013. DOI: 10.1016/j.jhydrol.2013.04.048 START YEAR: 1000 AD * END YEAR: 2010 AD -121.7814 42.2008 -121.7814 42.2008