noaa-recon-17556 California 1200 Year PDSI and 700 Year Precipitation Reconstructions Griffin, D.; Anchukaitis, K.J. California 1200 Year PDSI and 700 Year Precipitation Reconstructions 2014-12-09 NCDC-Paleoclimatology ONLINE Files Pending https://www.ncdc.noaa.gov/paleo/study/17556 Investigator D. Griffin Investigator K.J. Anchukaitis 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,two root mean square error upper bound,unspecified unit,Oct-Jun,climate reconstructions|tree ring,null,null,N,from regional blue oak tree ring chronology earth science paleoclimate instrumental precipitation,null,null,dimensionless,Oct-Jun,instrumental,normalized,null,N,null earth science paleoclimate climate reconstructions|tree ring precipitation,null,null,unspecified unit,Oct-Jun,climate reconstructions|tree ring,null,null,N,from regional blue oak tree ring chronology earth science paleoclimate climate reconstructions|tree ring precipitation,null,one root mean square error upper bound,unspecified unit,Oct-Jun,climate reconstructions|tree ring,null,null,N,from regional blue oak tree ring chronology earth science paleoclimate instrumental Palmer Drought Severity Index,null,null,dimensionless,Jun-Aug,instrumental,null,null,N,null earth science paleoclimate tree ring tree ring standardized growth index,null,null,null,null,tree ring,composited,null,N,regional blue oak tree ring chronology earth science paleoclimate climate reconstructions|tree ring Palmer Drought Severity Index,null,one root mean square error upper bound,dimensionless,Jun-Aug,climate reconstructions|tree ring,corrected,null,N,from North American Drought Atlas; mean shifted and variance scaled to match observed PDSI earth science paleoclimate climate reconstructions|tree ring precipitation,null,one root mean square error lower bound,unspecified unit,Oct-Jun,climate reconstructions|tree ring,null,null,N,from regional blue oak tree ring chronology earth science paleoclimate climate reconstructions|tree ring Palmer Drought Severity Index,null,null,dimensionless,Jun-Aug,climate reconstructions|tree ring,null,null,N,from North American Drought Atlas earth science paleoclimate climate reconstructions|tree ring Palmer Drought Severity Index,null,null,dimensionless,Jun-Aug,climate reconstructions|tree ring,corrected,null,N,from North American Drought Atlas; mean shifted and variance scaled to match observed PDSI earth science paleoclimate climate reconstructions|tree ring Palmer Drought Severity Index,null,two root mean square error lower bound,dimensionless,Jun-Aug,climate reconstructions|tree ring,corrected,null,N,from North American Drought Atlas; mean shifted and variance scaled to match observed PDSI earth science paleoclimate climate reconstructions|tree ring precipitation,null,two root mean square error lower bound,unspecified unit,Oct-Jun,climate reconstructions|tree ring,null,null,N,from regional blue oak tree ring chronology earth science paleoclimate climate reconstructions|tree ring Palmer Drought Severity Index,null,two root mean square error upper bound,dimensionless,Jun-Aug,climate reconstructions|tree ring,corrected,null,N,from North American Drought Atlas; mean shifted and variance scaled to match observed PDSI earth science paleoclimate climate reconstructions|tree ring Palmer Drought Severity Index,null,one root mean square error lower bound,dimensionless,Jun-Aug,climate reconstructions|tree ring,corrected,null,N,from North American Drought Atlas; mean shifted and variance scaled to match observed PDSI earth science paleoclimate reconstructions precipitation geoscientificInformation Palmer Drought Index Reconstruction Precipitation Reconstruction drought 800 AD 2014 AD 1150 cal yr BP -64 cal yr BP Complete 32.5 38.5 -123 -114 Continent North America United States Of America California California Divisions 4-7>LATITUDE >LONGITUDE None Please cite original publication, online resource, dataset and publication DOIs (where available), and date accessed when using downloaded data. If there is no publication information, please cite investigator, title, online resource, and date accessed. The appearance of external links associated with a dataset does not constitute endorsement by the Department of Commerce/National Oceanic and Atmospheric Administration of external Web sites or the information, products or services contained therein. For other than authorized activities, the Department of Commerce/NOAA does not exercise any editorial control over the information you may find at these locations. These links are provided consistent with the stated purpose of this Department of Commerce/NOAA Web site. English DOC/NOAA/NESDIS/NCEI National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce https://www.ncdc.noaa.gov/data-access/paleoclimatology-data DATA Center Contact Bruce Bauer bruce.a.bauer@noaa.gov paleo@noaa.gov 303-497-6280 303-497-6513

325 Broadway, E/NE31

Boulder CO 80305-3328 USA online ASCII Daniel Griffin and Kevin J. Anchukaitis 2014 Geophysical Research Letters 10.1002/2014GL062433 http://onlinelibrary.wiley.com/doi/10.1002/2014GL062433/abstract

For the past three years (2012-2014), California has experienced the most severe drought conditions in its last century. But how unusual is this event? Here we use two paleoclimate reconstructions of drought and precipitation for Central and Southern California to place this current event in the context of the last millennium. We demonstrate that while 3-year periods of persistent below-average soil moisture are not uncommon, the current event is the most severe drought in the last 1200 years, with single year (2014) and accumulated moisture deficits worse than any previous continuous span of dry years. Tree-ring chronologies extended through the 2014 growing season reveal that precipitation during the drought has been anomalously low but not outside the range of natural variability. The current California drought is exceptionally severe in the context of at least the last millennium and is driven by reduced though not unprecedented precipitation and record high temperatures. STUDY NOTES: Tree-ring based (blue oak, Quercus douglasii) reconstructions of precipitation (1293-2014 AD) and Palmer Drought Severity Index (PDSI) (800-2014 AD) for California State Climate Divisions 4, 5, 6, and 7 (southern 2/3 of California, roughly south of Sacramento).

GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/treering/reconstructions/california/griffin2015drought.txt Data File; California PDSI and Precipitation Reconstructions USA/NOAA DIF Version 9.8.4 2019-03-01 2019-03-01