noaa-icecore-14172 WAIS Divide Ice Core 2400 Year Sulfate and Nitrate Isotope Data 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. WAIS Divide Ice Core 2400 Year Sulfate and Nitrate Isotope Data 2013-03-28 NCDC-Paleoclimatology ONLINE Files Pending https://www.ncdc.noaa.gov/paleo/study/14172 Investigator E.D. Sofen Investigator B. Alexander Investigator E.J. Steig Investigator M.H. Thiemens Investigator S.A. Kunasek Investigator H.M. Amos Investigator A.J. Schauer Investigator M.G. Hastings Investigator J. Bautista Investigator T.L. Jackson Investigator L.E. Vogel Investigator J.R. McConnell Investigator D.R. Pasteris Investigator E.S. Saltzman earth science paleoclimate ice cores notes,null,null,null,null,ice cores,null,null,C,null earth science paleoclimate ice cores depth at sample start,null,null,meter,null,ice cores,null,null,N,null earth science paleoclimate ice cores delta 15N,nitrate,one standard deviation,per mil AIR,null,ice cores,averaged,continuous-flow isotope ratio mass spectrometry,N,null earth science paleoclimate ice cores nitrate,bulk ice,null,parts per billion,null,ice cores,averaged,inductively-coupled plasma mass spectrometry,N,null earth science paleoclimate ice cores delta 17O excess,sulfate,null,per mil SMOW,null,ice cores,averaged|corrected,continuous-flow isotope ratio mass spectrometry,N,corrected: isotopic exchange with quartz earth science paleoclimate ice cores methanesulfonic acid,bulk ice,null,parts per billion,null,ice cores,averaged,electrospray ionization mass spectrometry,N,null earth science paleoclimate ice cores delta 17O excess,nitrate,null,per mil VSMOW,null,ice cores,averaged,null,N,null earth science paleoclimate ice cores delta 18O,bulk ice,null,per mil VSMOW,null,ice cores,averaged,inductively-coupled plasma mass spectrometry,N,null earth science paleoclimate ice cores depth at sample end,null,null,meter,null,ice cores,null,null,N,null earth science paleoclimate ice cores delta 17O excess,nitrate,one standard deviation,per mil VSMOW,null,ice cores,averaged,continuous-flow isotope ratio mass spectrometry,N,null earth science paleoclimate ice cores delta 17O excess,sulfate,null,per mil SMOW,null,ice cores,averaged,continuous-flow isotope ratio mass spectrometry,N,null earth science paleoclimate ice cores delta 17O excess,nitrate,one standard deviation,per mil VSMOW,null,ice cores,averaged,null,N,null earth science paleoclimate ice cores delta 15N,nitrate,one standard deviation,per mil AIR,null,ice cores,averaged,null,N,null earth science paleoclimate ice cores accumulation rate,bulk ice,null,centimeter per year,null,ice cores,averaged,null,N,water equivalent earth science paleoclimate ice cores delta 17O excess,sulfate,one standard deviation,per mil SMOW,null,ice cores,averaged,continuous-flow isotope ratio mass spectrometry,N,null earth science paleoclimate ice cores accumulation rate,bulk ice,null,centimeter per year,null,ice cores,averaged,null,N,null earth science paleoclimate ice cores sulfur,bulk ice,null,parts per billion,null,ice cores,averaged,inductively-coupled plasma mass spectrometry,N,null earth science paleoclimate ice cores acidity,bulk ice,null,micromole,null,ice cores,averaged,inductively-coupled plasma mass spectrometry,N,null earth science paleoclimate ice cores age at sample end,null,null,year Common Era,null,ice cores,null,null,N,null earth science paleoclimate ice cores delta 17O excess,nitrate,null,per mil VSMOW,null,ice cores,averaged,continuous-flow isotope ratio mass spectrometry,N,null earth science paleoclimate ice cores hydrogen peroxide,bulk ice,null,parts per billion,null,ice cores,averaged,inductively-coupled plasma mass spectrometry,N,null earth science paleoclimate ice cores sulfate,bulk ice,null,nanogram per gram,null,ice cores,null,null,N,null earth science paleoclimate ice cores age at sample start,null,null,year Common Era,null,ice cores,null,null,N,null earth science paleoclimate ice cores sodium,bulk ice,null,parts per billion,null,ice cores,averaged,inductively-coupled plasma mass spectrometry,N,null earth science paleoclimate ice cores delta 15N,nitrate,null,per mil AIR,null,ice cores,averaged,continuous-flow isotope ratio mass spectrometry,N,null earth science paleoclimate ice cores sodium,bulk ice,null,nanogram per gram,null,ice cores,null,continuous flow analysis,N,null earth science paleoclimate ice cores sea salt,bulk ice,null,fraction,null,ice cores,null,null,N,fraction of total sulfate earth science paleoclimate ice cores delta 17O excess,non-sea-salt sulfate,null,per mil VSMOW,null,ice cores,corrected,null,N,corrected: isotopic exchange with quartz earth science paleoclimate ice cores delta 15N,nitrate,null,per mil AIR,null,ice cores,averaged,null,N,null earth science paleoclimate ice core nitrogen isotopes earth science paleoclimate ice core oxygen isotopes geoscientificInformation -427 AD 2008 AD 2377 cal yr BP -58 cal yr BP Complete -79.47 -79.4676 -112.13 -112.08 1759 1806 Continent Antarctica WAIS Divide WDC06A>LATITUDE -79.4676>LONGITUDE -112.0865 Continent Antarctica WAIS Divide WDC05A>LATITUDE -79.47>LONGITUDE -112.13 Continent Antarctica WAIS Divide WDC05Q>LATITUDE -79.47>LONGITUDE -112.08 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

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Boulder CO 80305-3328 USA online ASCII 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 2014 Atmospheric Chemistry and Physics 14 11 5749-5769 10.5194/acp-14-5749-2014 http://www.atmos-chem-phys.net/14/5749/2014/acp-14-5749-2014.html

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. STUDY NOTES: 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).

GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/antarctica/wais2013so4no3iso.txt GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/antarctica/wais2013d17o.txt GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/antarctica/wais2013sulfate-nitrate-d17o.xlsx GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/antarctica/wais2013d15n.txt USA/NOAA DIF Version 9.8.4 2019-05-06 2019-05-06