# WAIS Divide Ice Core 2400 Year Sulfate and Nitrate Isotope Data #----------------------------------------------------------------------- # World Data Center for Paleoclimatology, Boulder # and # NOAA Paleoclimatology Program #----------------------------------------------------------------------- # NOTE: Please cite original reference when using these data, # plus the Online Resource and date accessed. # # Online_Resource: http://www.ncdc.noaa.gov/paleo/study/14172 # # Original_Source_URL: ftp://ftp.ncdc.noaa.gov/pub/data/paleo/icecore/antarctica/wais2013d17o.txt # # Description/Documentation lines begin with # # Data lines have no # # # Archive: Ice Cores #-------------------- # Contribution_Date # Date: 2013-03-28 # Updated: 2014-10-07 #-------------------- # Title # Study_Name: WAIS Divide Ice Core 2400 Year Sulfate and Nitrate Isotope Data #-------------------- # Investigators # Investigators: Sofen, E.D.; Alexander, B.; Steig, E.J.; Thiemens, M.H.; Kunasek, S.A.; Amos, H.M.; Schauer, A.J.; Hastings, M.G.; Bautista, J.; Jackson, T.L.; Vogel, L.E.; McConnell, J.R.; Pasteris, D.R.; Saltzman, E.S. #-------------------- # Description_and_Notes # Description: Isotopic composition of sulfate and nitrate from 3 WAIS Divide Ice Cores. Data set updated 10/7/2014 to add age model, correct citation, # and add additional data (accumulation, MSA, NO3-, H2O2, Sulfur, Acid, NA+, water d18O). #-------------------- # Publication # Authors: Sofen, E.D., B. Alexander, E.J. Steig, M.H. Thiemens, S.A. Kunasek, H.M. Amos, A.J. Schauer, M.G. Hastings, J. Bautista, T.L. Jackson, L.E. Vogel, J.R. McConnell, D.R. Pasteris, and E.S. Saltzman # Published_Date_or_Year: 2014-06-11 # Published_Title: WAIS Divide ice core record suggests sustained changes in the chemical formation pathways of sulfate and nitrate aerosol since the 19th century # Journal_Name: Atmospheric Chemistry and Physics # Volume: 14 # Edition: # Issue: 11 # Pages: 5749-5769 # DOI: 10.5194/acp-14-5749-2014 # Online_Resource: http://www.atmos-chem-phys.net/14/5749/2014/acp-14-5749-2014.html # Abstract: The 17O excess (D17O = d17O-0.52 x d18O) of sulfate and nitrate reflects the relative importance of their different production pathways in the atmosphere. A new record of sulfate and nitrate D17O spanning the last 2400 years from the West Antarctic Ice Sheet Divide ice core project shows significant changes in both sulfate and nitrate D17O in the most recent 200 years, indicating changes in their formation pathways. The sulfate D17O record exhibits a 1.1 per mil increase in the early 19th century from (2.4 +/- 0.2) per mil to (3.5 +/- 0.2) per mil, which suggests that an additional 12-18% of sulfate formation occurs via aqueous-phase production by O3, relative to that in the gas phase. Nitrate D17O gradually decreases over the whole record, with a more rapid decrease between the mid-19th century and the present day of 5.6 per mil, indicating an increasing importance of RO2 in NOx cycling between the mid-19th century and the present day in the mid- to high-latitude Southern Hemisphere. The former has implications for the climate impacts of sulfate aerosol, while the latter has implications for the tropospheric O3 production rate in remote low-NOx environments. Using other ice core observations, we rule out drivers for these changes other than variability in extratropical oxidant (OH, O3, RO2, H2O2, and reactive halogens) concentrations. However, assuming OH, H2O2, and O3 are the main oxidants contributing to sulfate formation, Monte Carlo box model simulations require a large (>= 260%) increase in the O3 /OH mole fraction ratio over the Southern Ocean in the early 19th century to match the sulfate D17O record. This unlikely scenario points to a~deficiency in our understanding of sulfur chemistry and suggests other oxidants may play an important role in sulfate formation in the mid- to high-latitude marine boundary layer. The observed decrease in nitrate D17O since the mid-19th century is most likely due to an increased importance of RO2 over O3 in NOx cycling and can be explained by a 60-90% decrease in the O3 / RO2 mole fraction ratio in the extratropical Southern Hemisphere NOx-source regions. #------------------ # Funding_Agency # Funding_Agency_Name: US National Science Foundation # Grant: ANT-0538049, AGS-0704169 #------------------ # Site_Information # Site_Name: WDC-05Q # Location: Antarctica # Region: # Country: # Northernmost_Latitude: -79.4675 # Southernmost_Latitude: -79.4675 # Easternmost_Longitude: -112.0856 # Westernmost_Longitude: -112.0856 # Elevation: 1806 m #------------------ # Data_Collection # Collection_Name: WDC05Qd17O # Earliest_Year: 1523 # Most_Recent_Year: 2000 # Time_Unit: AD # Core_Length: 128.65 m # Notes: #------------------ # Chronology: # # # #---------------- # Variables # # Data variables follow (have no #) # Data line variables format: Variables list, one per line, shortname-tab-longname-tab-longname components (9 components: what, material, error, units, seasonality, archive, detail, method, C or N for Character or Numeric data) # WDC05Q Nitrate D17O st. dev. per mil based on triplicate measurements of samples # ##depth_top_m Depth top of sample interval, , , m, , ,top of sample, ,N ##depth_bot_m Depth bottom of sample interval, , , m, , ,bottom of sample, ,N ##age_AD_top Age top of sample interval, , , year AD, , ,top of sample, ,N ##age_AD_bot Age bottom of sample interval, , , year AD, , ,bottom of sample, ,N ##d17ONO3 delta 17O Nitrate, , , per mil, , , , ,N ##d17ONO3std delta 17O Nitrate standard deviation, , , per mil, , , , ,N ##ice_accum_cm Ice accumulation rate, , , cm/yr, , , water equivalent, ,N ##MSA Methanesulfonic acid (MSA), , , ng/g, , , , ,N ##no3_ppb NO3 - concentration, , , ppb, , , , ,N ##n2o2_ppb N2O2 - concentration, , , ppb, , , , ,N # # #---------------- # Data: # Data lines follow (have no #) # Data line format - tab-delimited text, variable short name as header # Missing Values: depth_top_m depth_bot_m age_AD_top age_AD_bot d17ONO3 d17ONO3std ice_accum_cm MSA no3_ppb n2o2_ppb 2.96 4 2000.3 1997.8 29.99 1.84 17.1 5.33 42.9 72.7 4 5.09 1997.8 1995 26.81 1.6 16.1 6.37 44.2 61.5 6.166 7.2 1992.8 1990.5 21.35 1.73 20.0 7.18 50.3 71.0 7.2 8.24 1990.5 1987.8 24.55 1.82 18.1 4.25 46.3 55.3 8.24 9.255 1987.8 1985.1 23.99 1.34 18.4 5.04 39.1 51.1 9.255 10.25 1985.1 1982.6 27.58 1.54 19.3 5.37 40.2 53.3 10.25 11.29 1982.6 1980.2 29.69 1.66 21.5 3.84 36.9 39.5 11.29 12.33 1980.2 1977.2 31.39 1.76 18.0 7.09 39.9 42.9 12.33 13.43 1977.2 1973.8 28.47 3.8 16.7 9.63 59.4 42.3 13.43 14.46 1973.8 1970.7 28.55 1.96 17.7 4.25 39.3 24.7 14.46 15.48 1970.7 1967.7 23.84 1.33 18.2 5.00 48.5 43.9 15.48 16.53 1967.7 1964.8 27.21 2.51 19.3 6.87 43.3 35.8 16.53 17.58 1964.8 1961.4 22.41 1.78 17.2 8.37 41.6 33.1 17.58 18.595 1961.4 1958.5 27.2 1.52 19.0 6.43 34.3 33.2 18.595 19.65 1958.5 1954.9 30.28 1.83 16.5 7.38 49.5 34.3 20.695 21.715 1952 1948.7 27.89 1.56 18.0 6.97 36.0 34.8 21.715 22.725 1948.7 1945.7 29.59 2.78 19.0 6.20 38.4 34.5 22.725 23.785 1945.7 1942.2 28.04 2.35 17.7 8.54 46.7 38.0 23.785 24.815 1942.2 1939.3 26.79 1.77 20.5 8.24 38.4 48.4 24.815 25.915 1939.3 1935.9 29.86 1.67 18.8 6.10 38.8 34.1 25.915 27.005 1935.9 1932.5 35.19 1.97 18.9 7.08 45.1 38.5 27.005 28.03 1932.5 1929.3 30.72 1.72 19.1 7.70 42.7 27.1 28.03 29.055 1929.3 1926.1 28.01 2.91 19.2 10.06 46.8 32.5 29.055 30.1 1926.1 1922 27.58 1.54 15.4 7.91 45.2 26.4 30.1 31.125 1922 1919.1 27.84 1.56 21.1 4.71 37.7 23.5 31.125 32.16 1919.1 1915.7 29.98 2.39 18.7 5.53 40.1 35.5 32.16 33.195 1915.7 1912.2 28.99 1.62 17.7 5.66 43.8 36.5 33.195 34.24 1912.2 1907.9 34.22 1.92 15.3 5.86 48.2 30.2 34.24 35.245 1907.9 1904.3 30.86 1.73 17.3 5.78 36.4 45.3 35.245 36.265 1904.3 1901.3 31.02 3.9 20.9 9.84 45.8 34.9 36.265 37.28 1901.3 1898.1 27.33 1.75 20.2 5.57 32.6 36.6 37.28 38.325 1898.1 1894.3 34.13 1.91 17.3 5.75 35.8 36.3 38.325 39.375 1894.3 1890.5 31.59 1.77 17.6 5.27 39.9 28.8 39.375 40.39 1890.5 1887.2 32.43 2.05 19.6 5.77 35.4 28.0 40.39 41.435 1887.2 1883.5 41.45 2.32 17.9 5.44 44.1 18.0 41.435 42.45 1883.5 1879.8 36.97 2.56 18.2 5.26 47.5 26.1 42.45 43.51 1879.8 1876.5 35.16 2.89 20.4 8.07 42.8 32.4 43.51 44.555 1876.5 1872.8 29.14 1.63 18.8 3.74 40.8 33.0 44.555 45.605 1872.8 1868.4 30.13 1.89 15.6 6.53 40.5 27.2 45.605 46.625 1868.4 1864.7 30.94 4.84 18.7 7.28 41.5 24.2 46.625 47.655 1864.7 1860.6 31.62 2 16.6 5.55 47.4 20.5 47.655 48.685 1860.6 1856.4 28.7 1.61 16.6 6.41 39.7 24.0 48.685 49.79 1856.4 1852.1 32.66 2.5 17.3 4.89 37.0 22.1 49.79 50.805 1852.1 1848.4 31.61 1.77 18.8 6.36 38.8 25.4 50.805 51.85 1848.4 1844.4 31.48 2.16 17.7 8.96 32.3 18.9 51.85 52.825 1844.4 1840.8 31.1 1.74 18.6 8.38 31.0 24.1 52.825 53.895 1840.8 1836.4 30.7 2.39 16.9 9.05 38.6 25.9 53.895 54.91 1836.4 1832.7 29.74 2.35 19.2 10.06 38.6 28.9 54.91 55.92 1832.7 1828.7 30.35 1.7 17.6 6.35 48.8 22.0 55.92 56.98 1828.7 1824.8 31.4 1.76 19.2 7.82 41.7 19.1 56.98 58.01 1824.8 1821.1 32.38 2.26 20.2 7.75 42.1 26.1 58.01 59.055 1821.1 1817.1 35.62 2.88 18.3 7.73 42.0 18.7 59.055 60.085 1817.1 1813.1 27.4 1.53 18.5 8.00 36.2 23.9 60.085 61.085 1813.1 1809.1 32.75 1.83 18.3 6.54 43.1 23.9 61.085 62.08 1809.1 1804.7 31.81 2.53 16.2 6.65 36.0 17.2 62.08 63.17 1804.7 1800.1 34.31 3.03 17.6 8.06 40.0 28.4 63.17 64.165 1800.1 1795.7 27.32 1.53 16.6 11.52 33.6 26.1 64.165 65.175 1795.7 1792 30.79 1.72 20.1 9.72 39.4 33.8 65.175 66.28 1792 1787.9 31.98 1.79 19.9 7.96 38.1 31.6 66.28 67.28 1787.9 1784 29.56 1.66 19.2 8.69 39.4 22.3 67.28 68.34 1784 1779.8 28.77 2.92 18.8 8.75 37.8 28.2 68.34 69.38 1779.8 1775.7 29.25 1.64 18.8 11.62 40.7 24.9 69.38 70.37 1775.7 1771.7 29.02 1.62 18.7 10.75 37.0 22.3 70.37 71.415 1771.7 1767.4 27.81 1.66 18.5 10.90 43.6 28.1 71.415 72.505 1767.4 1763.1 33.51 1.88 19.0 9.16 41.3 28.3 72.505 73.44 1763.1 1759.3 30.03 1.78 18.8 9.97 39.6 19.3 73.44 74.435 1759.3 1754.7 34.68 3.95 16.8 8.76 37.2 27.3 74.435 75.475 1754.7 1750.1 29.07 2.78 17.2 9.82 42.8 21.7 75.475 76.54 1750.1 1745.7 32.15 1.8 18.8 8.81 38.1 27.0 76.54 77.515 1745.7 1741.3 29.32 1.64 17.2 8.14 42.7 23.6 77.515 78.52 1741.3 1736.7 38.76 2.26 16.9 9.05 39.9 23.9 78.52 79.61 1736.7 1732.2 33.01 2.91 19.0 10.69 36.5 28.8 79.61 80.63 1732.2 1727.4 37.77 2.11 16.6 7.61 35.9 24.4 80.63 81.685 1727.4 1722 34.81 1.95 15.3 8.04 32.8 20.5 81.685 82.705 1722 1718.1 32.71 1.94 20.6 7.80 41.1 28.7 82.705 83.67 1718.1 1714.5 29.77 1.94 20.9 9.36 43.3 24.1 83.67 84.74 1714.5 1709.9 28.45 1.59 18.3 8.78 34.2 25.2 84.74 85.72 1709.9 1705.1 32.09 2.06 16.1 7.40 38.5 30.8 85.72 86.72 1705.1 1700.6 31.26 1.75 17.9 9.83 37.2 24.2 86.72 87.735 1700.6 1697.2 29.3 1.64 23.2 7.24 45.2 17.6 87.735 88.71 1697.2 1693.1 26.69 1.49 19.0 9.22 38.5 26.6 88.71 89.64 1693.1 1689.4 28.14 2.34 20.1 8.91 37.9 32.8 89.64 90.735 1689.4 1684.1 28.43 1.59 16.6 10.54 36.3 23.7 90.735 91.745 1684.1 1679.1 32.58 1.82 16.3 8.10 43.3 20.8 91.745 92.77 1679.1 1674.5 34.79 1.95 18.0 6.39 46.4 22.3 92.77 93.745 1674.5 1670.5 29.63 1.66 19.4 8.07 35.8 20.1 93.745 94.84 1670.5 1665.6 27.74 1.55 18.1 9.42 37.7 26.0 94.84 95.87 1665.6 1661.1 28.9 2.17 18.8 9.30 35.7 24.6 95.87 96.895 1661.1 1657.3 37 2.07 21.8 7.19 47.8 23.8 96.895 97.87 1657.3 1653.7 32.86 1.84 21.8 7.20 45.3 24.8 97.87 98.9 1653.7 1649.7 39.54 2.21 21.1 6.98 31.8 27.7 98.9 99.9 1649.7 1645.7 26.05 2.25 20.4 10.90 36.6 19.3 99.9 100.9 1645.7 1641.3 36.82 3.37 18.6 6.64 41.5 22.0 100.9 101.895 1641.3 1637.1 31.31 1.75 19.0 7.04 44.6 31.4 101.895 102.705 1637.1 1633.6 31.18 1.75 19.1 6.98 48.0 20.6 102.705 103.605 1633.6 1630.5 30.12 1.88 24.1 8.77 41.9 20.1 103.605 104.6 1630.5 1626.8 29.34 1.64 21.7 10.07 40.5 23.5 104.6 105.565 1626.8 1622.6 28.05 2.78 18.9 9.19 38.6 26.6 105.565 106.525 1622.6 1618.5 29.32 1.64 19.3 9.67 38.2 21.5 106.525 107.62 1618.5 1613.8 30.33 1.7 19.5 5.62 57.5 26.3 107.62 108.62 1613.8 1610 32.6 2.18 21.6 10.42 40.8 23.9 108.62 109.58 1610 1605.7 33.42 1.99 18.6 9.58 39.5 29.8 109.58 110.575 1605.7 1600.6 31.44 1.76 16.1 9.69 37.2 18.7 110.575 111.64 1600.6 1596.3 34.61 1.94 20.6 9.54 33.4 22.1 111.64 112.65 1596.3 1592.5 35.98 2.01 22.0 11.73 36.6 33.5 112.65 113.6 1592.5 1588.8 32.91 1.84 21.2 8.21 34.3 27.0 113.6 114.63 1588.8 1584 31.59 1.77 18.2 10.24 40.1 26.4 114.63 115.645 1584 1580 32.32 2.6 20.9 7.92 41.9 27.8 115.645 116.735 1580 1574.9 34.64 1.94 17.8 8.28 37.8 29.1 116.735 117.7 1574.9 1570.2 30.57 2.43 17.3 7.30 43.3 23.7 117.7 118.725 1570.2 1565.9 37.51 2.1 19.7 8.86 41.4 22.8 118.725 119.785 1565.9 1561 39.14 3.26 18.4 7.68 35.1 25.3 119.785 120.85 1561 1556.5 31.06 1.74 19.6 10.94 39.0 29.1 120.85 121.93 1556.5 1552.2 43.74 2.45 21.2 9.61 40.1 33.8 121.93 123.01 1552.2 1547.8 28.92 1.62 20.8 9.65 46.0 30.2 123.01 124.07 1547.8 1543.2 32.92 1.84 19.4 10.61 44.6 25.0 124.07 125.135 1543.2 1538.2 29.31 3.7 18.2 9.71 42.8 23.3 125.135 126.2 1538.2 1534.1 30.25 2.57 21.9 8.30 39.7 27.1 126.2 127.28 1534.1 1529.5 23.79 1.33 19.6 9.06 41.4 27.6 127.28 128.65 1529.5 1523.4 30.95 2.66 19.1 10.42 40.1 32.1 128.65 129.196 1523.4 1521 22.78 1.28 19.6 10.31 46.2 31.9