US Mid-Atlantic Region 800 Year May Precipitation Reconstruction Maxwell, R.S.; Hessl, A.E.; Cook, E.R.; Buckley, B.M. Maxwell, R.S. Hessl, A.E. Cook, E.R. Buckley, B.M. Precipitation Reconstruction drought 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/instrumental (precipitation,null,null,millimeter,May,instrumental,null,null,N,null) earth science/paleoclimate/climate reconstructions|tree ring (precipitation,null,null,millimeter,May,climate reconstructions|tree ring,null,null,N,null) earth science/paleoclimate/reconstructions (US Mid-Atlantic Region>LATITUDE 37.5>LONGITUDE -77.5) We present a multi-century reconstruction of May precipitation (1200 - 1997) for the Mid-Atlantic Region of the United States. The reconstruction is based on the first principal component (PC1) of two millennial-length Juniperus virginiana L. (eastern redcedar) tree-ring chronologies collected from rocky, limestone sites in the Ridge and Valley province of West Virginia. A split-calibration linear regression model accounted for 27% of the adjusted variance in the instrumental record and was stable through time. The model was verified by the reduction of error (RE = 0.21) and coefficient of efficiency (CE = 0.20) statistics. Multi-decadal changes in precipitation were common throughout the reconstruction, and wetter than median conditions and drier than median conditions occurred during the Medieval Climate Anomaly (1200 - 1300) and the Little Ice Age (1550 - 1650), respectively. The full reconstruction contained evidence of inter-annual and decadal variability; however, the 20th century recorded the greatest number of decadal extreme wet and dry periods. A comparison of the May precipitation reconstruction to other regional reconstructions of Potomac River, Maryland streamflow (Cook and Jacoby 1983), Virginia/North Carolina July Palmer Hydrologic Drought Index (PHDI; Stahle et al. 1998), Missouri July PHDI (Cleaveland and Stahle 1994), and White River, Arkansas streamflow (Cleaveland 2000) showed that eastern US decadal drought and pluvial events extended into the Mid-Atlantic Region. A positive correlation between PC1 and the winter North Atlantic Oscillation (NAO) Index and comparisons of smoothed May precipitation and NAO (Luterbacher et al. 1999) indicated that J. virginiana's response to May precipitation was mediated by winter temperature. STUDY NOTES: Reconstruction of May precipitation for AD 1200-1997 for the Mid-Atlantic Region of the United States. The reconstruction is based on two Juniperus virginiana L. (eastern redcedar) tree-ring chronologies collected in West Virginia. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Maxwell, R.S. Investigator : Hessl, A.E. Investigator : Cook, E.R. Investigator : Buckley, B.M. 2012-01-28 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/12425 https://www1.ncdc.noaa.gov/pub/data/paleo/treering/reconstructions/northamerica/usa/mid-atlantic2012precip.xls https://www1.ncdc.noaa.gov/pub/data/paleo/treering/reconstructions/northamerica/usa/mid-atlantic2012precip.txt https://www1.ncdc.noaa.gov/pub/data/paleo/treering/reconstructions/northamerica/usa/mid-atlantic2012precip.xls https://www1.ncdc.noaa.gov/pub/data/paleo/treering/reconstructions/northamerica/usa/mid-atlantic2012precip.txt English https://www.ncdc.noaa.gov/paleo/study/12425 https://www1.ncdc.noaa.gov/pub/data/paleo/treering/reconstructions/northamerica/usa/mid-atlantic2012precip.xls https://www1.ncdc.noaa.gov/pub/data/paleo/treering/reconstructions/northamerica/usa/mid-atlantic2012precip.txt Maxwell, R.S., A.E. Hessl, E.R. Cook, and B.M. Buckley. 2012. A multi-century reconstruction of May precipitation for the Mid-Atlantic Region using Juniperus virginiana tree rings. Journal of Climate, Early Online Release 20 September 2011. doi: http://dx.doi.org/10.1175/JCLI-D-11-00017.1 START YEAR: 1200 AD * END YEAR: 1997 AD -80 35 -75 40