# 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/wais2013so4no3iso.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-06A # Location: Antarctica # Region: # Country: # Northernmost_Latitude: -79.4676 # Southernmost_Latitude: -79.4676 # Easternmost_Longitude: -112.0865 # Westernmost_Longitude: -112.0865 # Elevation: 1806 m #------------------ # Data_Collection # Collection_Name: WDSO4NO3iso # Earliest_Year: -427 # Most_Recent_Year: 2008 # Time_Unit: AD # Core_Length: 577 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) # WAIS Divide Ice Core Sulfate and Nitrate Data # WDC05A and WDC05Q Nitrate D17O d15N are calculated as concentration-weighted averages of the 1 m resolution measurements included in this study # # ##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_ADtop Age top of sample interval, , , AD, , ,top of sample, ,N ##age_ADbot Age bottom of sample interval, , , AD, , ,bottom of sample, ,N ##notes notes core name, , , , , , , ,C ##d17OSO4 delta 17O Sulfate, , , per mil, , , , ,N ##d17OSO4std delta 17O Sulfate standard deviation, , , per mil, , , , ,N ##d17OSO4corr delta 17O Sulfate corrected for isotopic exchange with quartz, , , per mil, , , Sulfate d17O correction see see Schauer et al. RCMS 2012, ,N ##Na_ngg Na+ concentration, , , ng/g, , , , ,N ##SO4_ngg SO4 2- concentration, , , ng/g, , , , ,N ##ss Sea-salt fraction, , , , , , assumes sea salt [SO42-]/[Na+]=0.25 as in Kunasek et al. 2010, ,N ##d17OSO4nss delta 17O Sulfate non sea salt, , , per mil, , , corrected for isotopic exchange and sea salt sulfate, ,N ##notes notes core name, , , , , , , ,C ##d17ONO3 delta 17O Nitrate, , , per mil, , , , ,N ##d17ONO3std delta 17O Nitrate standard deviation, , , per mil, , , , ,N ##notes notes core name, , , , , , , ,C ##d15NNO3 delta 15N Nitrate, , , per mil, , , , ,N ##d15NNO3std delta 15N Nitrate standard deviation, , , per mil, , , , ,N ##notes notes core name, , , , , , , ,C ##ice_accum Ice accumulation, , , cm/year, , , water equivalent, ,N ##no3_ppb NO3 - concentration, , , ppb, , , , ,N ##MSA Methanesulfonic acid (MSA), , , ng/g, , , , ,N ##s_ppb sulfur, , , ng/g, , , , ,N ##acidity Acidity, , , uM, , , , ,N ##na_ppb Na, , , ng/g, , , , ,N ##d18Owater delta O18, water, , PDB, , , , ,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_ADtop age_ADbot notes d17OSO4 d17OSO4std d17OSO4corr Na_ngg SO4_ngg ss d17OSO4nss notes d17ONO3 d17ONO3std notes d15NNO3 d15NNO3std notes ice_accum no3_ppb MSA s_ppb acidity na_ppb d18Owater 0 12.16 2008 1978 WDC05A 2.40 0.1 2.80 21.19 27.50 0.19 3.46 WDC05Q 26.7 WDC05A 7.804944595 WDC06A 22.63 42.5 5.87 11.5 1.30 21.9 -33.91 12.17 21.16 1978 1951 WDC05A 2.20 0.1 2.57 24.33 28.28 0.22 3.27 WDC05Q 27.2 WDC05A 9.171804523 WDC06A 21.32 45.0 6.74 11.7 1.25 31.8 -34.62 21.16 29.69 1951 1924 WDC05Q 29.6 WDC05A 6.46854599 WDC06A 22.33 42.6 7.74 10.6 1.23 22.3 -33.88 29.69 42.55 1924 1880 WDC05A 2.30 0.1 2.68 22.02 26.59 0.21 3.38 WDC05Q 32.3 WDC05A 6.191684306 WDC06A 21.78 40.6 5.94 11.2 1.31 26.2 -33.87 42.56 53.92 1880 1837 WDC05A 2.50 0.1 2.91 23.91 27.42 0.22 3.72 WDC05Q 31.2 WDC05A 7.36153811 WDC06A 21.59 39.3 6.92 11.3 1.33 23.2 -34.03 53.93 60.96 1837 1810 WDC05A 2.30 0.1 2.68 24.35 42.15 0.14 3.13 WDC05Q 31.3 WDC05A 7.207149394 WDC06A 22.40 41.8 7.58 17.3 1.73 20.4 -33.60 60.97 69.85 1810 1774 WDC05A 1.70 0.1 2.00 25.51 30.78 0.21 2.52 WDC05Q 30.6 WDC05A 6.20148772 WDC06A 21.86 38.2 9.25 11.3 1.30 22.1 -33.56 69.85 81 1773 1725 WDC05Q 32.7 WDC06A 21.72 39.1 9.23 11.3 1.31 22.6 -34.00 81 92 1725 1676 WDC05Q 30.5 WDC06A 21.36 39.2 8.66 14.0 1.35 25.0 -33.95 92 103 1676 1632 WDC05Q 32.4 WDC06A 24.64 41.0 7.91 13.9 1.30 22.6 -33.76 103 114 1632 1586 WDC05Q 31.8 WDC06A 24.07 39.8 9.42 14.8 1.45 21.1 -33.75 114 126 WDC05Q 33.8 126 138 WDC05Q 27.4 114 126 1586 1533 WDC06A 1.56 0.1 1.83 22.74 25.92 0.22 2.35 WDC06A 34.59 0.15 WDC06A 7.77 0.15 WDC06A 23.65 40.9 9.06 12.3 1.28 22.7 -33.75 126 138 1533 1482 WDC06A 1.50 0.1 1.77 22.52 26.86 0.21 2.24 WDC06A 33.88 2.29 WDC06A 9.33 0.64 WDC06A 24.04 41.3 9.88 12.8 1.26 22.5 -33.86 138 151 1482 1422 WDC06A WDC06A 34.34 1.63 WDC06A 9.89 0.19 WDC06A 22.76 39.3 9.12 14.4 1.46 20.3 -33.84 151 163 1422 1369 WDC06A 1.64 0.1 1.93 20.43 25.75 0.20 2.41 WDC06A 34.74 0.13 WDC06A 7.58 0.22 WDC06A 23.90 39.9 9.41 12.3 1.36 20.4 -33.75 163 176 1369 1313 WDC06A 1.67 0.1 1.97 20.40 25.29 0.20 2.47 WDC06A 32.45 0.53 WDC06A 6.68 0.15 WDC06A 24.22 41.0 8.34 12.0 1.45 20.4 -33.85 176 188 1313 1258 WDC06A 1.81 0.1 2.13 21.47 29.67 0.18 2.60 WDC06A 36.62 0.36 WDC06A 8.90 0.33 WDC06A 23.07 40.2 9.11 14.1 1.82 21.5 -33.79 188 200 1258 1207 WDC06A 1.50 0.1 1.76 21.45 31.04 0.17 2.13 WDC06A 35.49 0.44 WDC06A 6.36 0.23 WDC06A 24.95 39.3 9.35 14.8 1.50 21.4 -33.55 200 213 1207 1149 WDC06A 1.48 0.1 1.74 19.97 27.18 0.18 2.13 WDC06A 34.23 0.51 WDC06A 5.89 0.27 WDC06A 23.71 37.6 10.02 12.9 1.40 20.0 -33.54 213 226 1149 1093 WDC06A 1.23 0.1 1.46 22.21 26.96 0.21 1.84 WDC06A 34.88 0.04 WDC06A 4.62 0.08 WDC06A 24.91 37.6 10.80 12.8 1.37 22.2 -33.84 226 240 1093 1032 WDC06A 1.78 0.1 2.09 19.88 25.89 0.19 2.59 WDC06A 35.26 0.56 WDC06A 7.28 0.35 WDC06A 24.80 33.6 9.50 12.3 1.32 19.9 -33.59 240 254 1032 973 WDC06A 1.83 0.1 2.14 19.70 25.62 0.19 2.65 WDC06A 35.48 0.19 WDC06A 7.12 0.31 WDC06A 25.36 33.6 8.89 12.2 1.32 19.7 -33.53 254 267 973 919 WDC06A 1.76 0.1 2.06 20.83 28.05 0.19 2.53 WDC06A 35.42 0.02 WDC06A 5.24 0.03 WDC06A 26.33 29.3 9.87 13.4 1.39 20.8 -33.35 267 280 919 865 WDC06A 1.65 0.1 1.94 19.69 26.74 0.18 2.37 WDC06A 34.97 0.42 WDC06A 7.48 2.11 WDC06A 25.84 28.4 9.50 12.7 1.43 19.7 -33.31 280 294 865 802 WDC06A 1.66 0.1 1.95 20.56 24.84 0.21 2.45 WDC06A 37.77 1.49 WDC06A 4.91 0.39 WDC06A 24.32 32.5 8.10 11.8 1.37 20.6 -33.33 294 309 802 738 WDC06A 1.65 0.1 1.94 20.78 23.82 0.22 2.48 WDC06A 32.99 0.78 WDC06A 5.80 0.18 WDC06A 25.85 31.0 8.33 11.3 1.32 20.8 -33.16 309 322 738 685 WDC06A 1.68 0.1 1.98 18.96 25.35 0.19 2.43 WDC06A 36.21 0.87 WDC06A 5.76 0.31 WDC06A 26.70 38.8 10.28 12.1 1.38 19.0 -32.95 322 334 685 633 WDC06A 1.78 0.1 2.09 19.89 30.21 0.16 2.50 WDC06A 35.1 1.8 WDC06A 7.27 0.12 WDC06A 25.89 38.2 10.11 14.4 1.46 19.9 -33.01 334 347 633 578 WDC06A 1.55 0.1 1.82 18.19 27.34 0.17 2.19 WDC06A 36.25 0.32 WDC06A 4.26 0.24 WDC06A 25.83 36.6 8.69 13.0 1.29 18.2 -32.83 347 359 578 527 WDC06A 1.60 0.1 1.89 15.23 25.12 0.15 2.22 WDC06A 36.62 1.14 WDC06A 5.33 1.17 WDC06A 26.43 36.7 8.12 12.0 1.41 15.2 -33.26 359 371 527 477 WDC06A 1.58 0.1 1.86 19.04 28.99 0.16 2.23 WDC06A 37.13 0.69 WDC06A 4.81 1.11 WDC06A 26.94 36.4 8.44 13.8 1.32 19.0 -32.84 371 383 477 426 WDC06A 1.48 0.1 1.75 20.23 31.02 0.16 2.09 WDC06A 33.29 1.08 WDC06A 4.05 0.27 WDC06A 26.36 37.6 10.47 14.8 1.31 20.2 -32.82 383 396 426 370 WDC06A 1.75 0.1 2.05 18.66 27.94 0.17 2.47 WDC06A 30.14 0.16 WDC06A 3.40 0.58 WDC06A 26.41 34.9 9.03 13.3 1.26 18.7 -33.27 396 409 370 316 WDC06A 1.17 0.1 1.39 22.04 27.39 0.20 1.74 WDC06A 27.73 0.09 WDC06A 1.53 0.35 WDC06A 26.97 32.8 9.13 13.0 1.29 22.0 -32.98 409 422 316 260 WDC06A 1.71 0.1 2.01 18.93 28.68 0.16 2.41 WDC06A 35.12 0.82 WDC06A 3.57 0.25 WDC06A 26.24 33.6 9.48 13.7 1.41 18.9 -33.33 422 436 260 195 WDC06A 1.85 0.1 2.16 17.84 26.58 0.17 2.60 WDC06A 35.54 0.27 WDC06A 5.47 0.11 WDC06A 24.95 31.3 9.36 12.7 1.40 17.8 -33.05 436 449 195 135 WDC06A WDC06A 36.21 2.29 WDC06A 4.78 0.06 WDC06A 24.54 33.3 9.63 13.1 1.42 19.7 -33.21 449 461 135 81 WDC06A WDC06A 35.53 1.19 WDC06A 5.59 0.46 WDC06A 25.81 34.3 14.0 1.43 20.2 -33.18 461 475 81 19 WDC06A 1.63 0.1 1.91 17.10 26.77 0.16 2.28 WDC06A 35.07 1.29 WDC06A 4.04 0.05 WDC06A 26.23 31.0 12.8 1.38 17.1 -32.71 475 490 19 -49 WDC06A 1.69 0.1 1.99 18.81 24.60 0.19 2.46 WDC06A 35.21 1.47 WDC06A 4.69 0.02 WDC06A 25.68 32.4 11.7 1.38 18.8 -33.21 490 505 -49 -117 WDC06A 1.47 0.1 1.73 19.36 23.47 0.21 2.18 WDC06A 34.32 3.55 WDC06A 4.15 0.10 WDC06A 25.60 31.6 11.2 1.28 19.4 -33.06 505 519 -117 -181 WDC06A 1.82 0.1 2.14 18.51 26.21 0.18 2.59 WDC06A 36.97 0.19 WDC06A 4.03 0.04 WDC06A 25.87 31.8 12.5 1.34 18.5 -32.85 519 534 -181 -247 WDC06A 1.68 0.1 1.97 19.37 23.85 0.20 2.48 WDC06A 35.19 0.56 WDC06A 4.27 0.03 WDC06A 26.93 31.7 11.4 1.33 19.4 -32.96 534 549 -247 -309 WDC06A 1.91 0.1 2.24 19.41 23.45 0.21 2.82 WDC06A 36.98 1.26 WDC06A 2.72 0.29 WDC06A 28.62 31.4 11.2 1.35 19.4 -32.98 549 564 -309 -372 WDC06A 1.70 0.1 1.99 21.35 24.23 0.22 2.56 WDC06A 35.84 0.13 WDC06A 4.18 0.16 WDC06A 28.22 31.0 11.5 1.21 21.3 -32.67 564 577 -372 -427 WDC06A 1.50 0.1 1.77 20.20 28.79 0.18 2.14 WDC06A 36.78 1.16 WDC06A 8.05 0.11 WDC06A 28.05 33.3 13.7 1.32 20.2 -32.54