Stable hydrogen and oxygen isotopic compositions of precipitation samples from selected Virginia and West Virginia National Atmospheric Deposition Program (NADP) sites

The stable hydrogen (delta 2H) and oxygen (delta 18O) isotopic compositions of more than 1,400 daily or weekly composite samples of precipitation from four National Atmospheric Deposition Program (NADP) sites (VA10, VA27, VA28, and WV99) in Virginia and West Virginia were analyzed on archived samples obtained from NADP over various time periods from as early as 1998. The samples are from the NADP National Trends Network (NTN) with weekly sample frequency, and the former NADP Atmospheric Integrated Research Monitoring Network (AIRMoN), sampled daily within 24 hours of start of precipitation. Data on site location, collection begin and end dates, sample volume and precipitation amounts were furnished from publicly-available NADP sources and were not evaluated for accuracy. The delta 2H and delta 18O values of 140 samples collected between 1997 and 2015 from a USGS collector collocated at NADP site VA28 were analyzed. The sample collection frequency varied between 5 and 126 days. Measured values range between -200.9 and +31.8 per mil for delta 2H and between -26.78 and +6.22 per mil for delta 18O. The data set of NAPD composite samples includes all the samples that were analyzed. Some isotope-delta values have been flagged as being out of range for natural waters, possibly in relation to low sample volumes or suboptimal storage conditions; however, the end user is responsible for evaluating all data for suitability for the intended purpose. Data files provided here include the metadata as an .xml file, a Microsoft Office Excel .xlsx file with four spreadsheets containing the Introduction, Table 1, Table 2, Table 3, and Table 4, and the individual data tables as comma-separated value .csv files. A plot of hydrogen versus oxygen isotopic compositions is also provided as a .jpg image. Data analysis was funded by the U.S Geological Survey (USGS) National Research Program and by the Laboratory and Analytical Services Division.