# Illimani Ice Core 1,600 Year Ammonium Data and Amazon Temperature Reconstruction #----------------------------------------------------------------------- # World Data Center for Paleoclimatology, Boulder # and # NOAA Paleoclimatology Program #----------------------------------------------------------------------- # NOTE: Please cite Publication, and Online_Resource and date accessed when using these data. # If there is no publication information, please cite Investigators, Title, and Online_Resource and date accessed. # # # Online_Resource: http://ncdc.noaa.gov/paleo/study/18057 # # Original_Source_URL: ftp://ftp.ncdc.noaa.gov/pub/data/paleo/icecore/trop/illimani/illimani2015nh4-10yr.txt # # Description/Documentation lines begin with # # Data lines have no # # # Archive: Ice Cores #-------------------- # Contribution_Date # Date: 2015-02-24 #-------------------- # Title # Study_Name: Illimani Ice Core 1,600 Year Ammonium Data and Amazon Temperature Reconstruction #-------------------- # Investigators # Investigators: Kellerhals, T.; Brutsch, S.; Sigl, M.; Knusel, S.; Gaggeler, H.W.; Schwikowski, M. #-------------------- # Description_and_Notes # Description: Ammonium (NH4+) data and reconstructed Tropical South American temperature from the 1999 Illimani ice core, # Bolivian Andes, for the past 1,600 years. Calibration/verification was performed for the period 1905-1998 based on annual # temperatures from the Amazon Basin subset of the gridded HadCRUT3 temperature data set. Dating uncertainties are <5 years # (AD 1800-1998) and <20 years (AD 350-1800). Temperature anomalies are given as annual values for the period AD 1800-1998 # and 10-year averages for the period AD 350-1998. # # In 1999, two parallel ice cores were retrieved from Nevado Illimani (16°37'S, 67°46′'W, 6300 m a.s.l.) # in a joint operation of the French Institut de Recherche pour le Developpement (IRD) and the Swiss # Paul Scherrer Institute (PSI). Both ice cores reached bedrock at depths of 138.7 and 136.7 m, respectively. # Nevado Illimani is located in the eastern Bolivian Andes at the northeastern margin of the Bolivian Altiplano. # Analyses of the major ions, trace elements, tritium, and 14C were performed at the Laboratory of Radiochemistry # and Environmental Chemistry (LCH) of the Paul Scherrer Institute (PSI) and the University of Bern, Switzerland. # The mean annual accumulation rate is 0.58 m water equivalent. # #-------------------- # Publication # Authors: T. Kellerhals, S. Brütsch, M. Sigl, S. Knüsel, H. W. Gäggeler, M. Schwikowski # Published_Date_or_Year: 2010-08-27 # Published_Title: Ammonium concentration in ice cores: A new proxy for regional temperature reconstruction? # Journal_Name: Journal of Geophysical Research - Atmospheres # Volume: 115 # Edition: D16123 # Issue: D16 # Pages: # DOI: 10.1029/2009JD012603 # Online_Resource: http://onlinelibrary.wiley.com/enhanced/doi/10.1029/2009JD012603/ # Full_Citation: # Abstract: We present a reconstruction of tropical South American temperature anomalies over the last ~1600 years. The reconstruction is based on a highly resolved and carefully dated ammonium record from an ice core that was drilled in 1999 on Nevado Illimani in the eastern Bolivian Andes. Concerning the relevant processes governing the observed correlation between ammonium concentrations and temperature anomalies, we discuss anthropogenic emissions, biomass burning, and precipitation changes but clearly favor a temperature-dependent source strength of the vegetation in the Amazon Basin. That given, the reconstruction reveals that Medieval Warm Period - and Little Ice Age - type episodes are distinguishable in tropical South America, a region for which until now only very limited temperature proxy data have been available. For the time period from about 1050 to 1300 AD, our reconstruction shows relatively warm conditions that are followed by cooler conditions from the 15th to the 18th century, when temperatures dropped by up to 0.6C below the 1961-1990 average. The last decades of the past millennium are characterized again by warm temperatures that seem to be unprecedented in the context of the last ~1600 years. #------------------ # Funding_Agency # Funding_Agency_Name: Institut de Recherche pour le Développement (IRD, France) # Grant: #------------------ # Funding_Agency # Funding_Agency_Name: Paul Scherrer Institute (PSI, Switzerland) # Grant: #------------------ # Site_Information # Site_Name: Illimani # Location: South America>Bolivia # Country: Bolivia # Northernmost_Latitude: -16.6167 # Southernmost_Latitude: -16.6167 # Easternmost_Longitude: -67.7667 # Westernmost_Longitude: -67.7667 # Elevation: 6300 m #------------------ # Data_Collection # Collection_Name: Illimani2015NH4-10yr # Earliest_Year: 355 # Most_Recent_Year: 1995 # Time_Unit: AD # Core_Length: 138.7m # Notes: #------------------ # Chronology: # # The timescale for the Illimani core was derived using annual layer-counting, known reference horizons # from nuclear bomb testing in 1964 AD, volcanic eruptions (Pinatubo (1991), El Chichón (1982), Agung (1963), # Krakatoa (1883), Tambora (1815), “unknown” (1258)) and six 14C dating points. A two‐parameter model # was fitted to the time markers to obtain a continuous depth‐age relationship. # # #---------------- # Variables # # Data variables follow that are preceded by "##" in columns one and two. # 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) # ##age_AD age, , , AD, , , , midpoint of 10-year interval,N ##nh4_ueq/l NH4+, , , microequivalent per liter, , , , 10-year average,N ##tempanom surface temperature anomaly, , , degrees C, , ice core, Amazon Basin, 10-year average vs. 1961-1990 mean,N ##tempanom2s- surface temperature anomaly lower 2 sigma, , , degrees C, , ice core, Amazon Basin, 10-year average,N ##tempanom2s+ surface temperature anomaly upper 2 sigma, , , degrees C, , ice core, Amazon Basin, 10-year average,N # #---------------- # Data: # Data lines follow (have no #) # Data line format - tab-delimited text, variable short name as header # Missing Values: # age_AD nh4_ueq/l tempanom tempanom2s- tempanom2s+ 355 3.75 -0.101 -0.381 0.179 365 2.25 -0.416 -0.696 -0.136 375 1.87 -0.496 -0.776 -0.216 385 2.24 -0.417 -0.697 -0.137 395 3.26 -0.205 -0.485 0.075 405 2.32 -0.400 -0.680 -0.120 415 3.00 -0.259 -0.539 0.021 425 1.73 -0.525 -0.805 -0.245 435 2.62 -0.339 -0.619 -0.059 445 2.72 -0.318 -0.598 -0.038 455 3.07 -0.244 -0.524 0.036 465 2.33 -0.400 -0.680 -0.120 475 2.69 -0.323 -0.603 -0.043 485 1.69 -0.533 -0.813 -0.253 495 2.37 -0.391 -0.671 -0.111 505 2.12 -0.443 -0.723 -0.163 515 2.20 -0.426 -0.706 -0.146 525 1.68 -0.534 -0.814 -0.254 535 1.88 -0.493 -0.773 -0.213 545 2.53 -0.356 -0.636 -0.076 555 2.14 -0.440 -0.720 -0.160 565 1.92 -0.484 -0.764 -0.204 575 2.52 -0.358 -0.638 -0.078 585 2.50 -0.364 -0.644 -0.084 595 2.51 -0.361 -0.641 -0.081 605 2.66 -0.330 -0.610 -0.050 615 2.26 -0.414 -0.694 -0.134 625 2.00 -0.467 -0.747 -0.187 635 2.23 -0.419 -0.699 -0.139 645 2.43 -0.378 -0.658 -0.098 655 1.88 -0.493 -0.773 -0.213 665 2.01 -0.466 -0.746 -0.186 675 1.70 -0.531 -0.811 -0.251 685 1.59 -0.553 -0.833 -0.273 695 1.54 -0.564 -0.844 -0.284 705 1.40 -0.594 -0.874 -0.314 715 1.80 -0.510 -0.790 -0.230 725 1.98 -0.472 -0.752 -0.192 735 2.18 -0.431 -0.711 -0.151 745 1.91 -0.486 -0.766 -0.206 755 2.72 -0.318 -0.598 -0.038 765 2.46 -0.372 -0.652 -0.092 775 1.64 -0.543 -0.823 -0.263 785 1.60 -0.552 -0.832 -0.272 795 1.80 -0.510 -0.790 -0.230 805 1.56 -0.559 -0.839 -0.279 815 1.42 -0.588 -0.868 -0.308 825 2.74 -0.313 -0.593 -0.033 835 1.06 -0.665 -0.945 -0.385 845 1.41 -0.591 -0.871 -0.311 855 2.43 -0.378 -0.658 -0.098 865 3.28 -0.202 -0.482 0.078 875 2.18 -0.430 -0.710 -0.150 885 1.78 -0.515 -0.795 -0.235 895 2.43 -0.378 -0.658 -0.098 905 1.74 -0.522 -0.802 -0.242 915 1.70 -0.531 -0.811 -0.251 925 1.93 -0.482 -0.762 -0.202 935 2.52 -0.359 -0.639 -0.079 945 2.87 -0.287 -0.567 -0.007 955 1.94 -0.481 -0.761 -0.201 965 2.56 -0.351 -0.631 -0.071 975 2.22 -0.423 -0.703 -0.143 985 2.03 -0.462 -0.742 -0.182 995 2.42 -0.381 -0.661 -0.101 1005 2.04 -0.459 -0.739 -0.179 1015 1.97 -0.474 -0.754 -0.194 1025 2.05 -0.457 -0.737 -0.177 1035 3.12 -0.233 -0.513 0.047 1045 2.64 -0.334 -0.614 -0.054 1055 4.29 0.011 -0.269 0.291 1065 3.25 -0.206 -0.486 0.074 1075 2.76 -0.309 -0.589 -0.029 1085 2.35 -0.396 -0.676 -0.116 1095 2.60 -0.342 -0.622 -0.062 1105 3.12 -0.234 -0.514 0.046 1115 3.06 -0.247 -0.527 0.033 1125 2.53 -0.357 -0.637 -0.077 1135 2.84 -0.293 -0.573 -0.013 1145 3.17 -0.224 -0.504 0.056 1155 3.60 -0.134 -0.414 0.146 1165 3.22 -0.212 -0.492 0.068 1175 2.64 -0.334 -0.614 -0.054 1185 2.28 -0.410 -0.690 -0.130 1195 3.61 -0.132 -0.412 0.148 1205 2.94 -0.272 -0.552 0.008 1215 3.03 -0.252 -0.532 0.028 1225 3.08 -0.242 -0.522 0.038 1235 2.84 -0.293 -0.573 -0.013 1245 2.90 -0.279 -0.559 0.001 1255 3.71 -0.110 -0.390 0.170 1265 3.74 -0.105 -0.385 0.175 1275 3.69 -0.114 -0.394 0.166 1285 3.20 -0.217 -0.497 0.063 1295 2.40 -0.384 -0.664 -0.104 1305 2.21 -0.425 -0.705 -0.145 1315 3.56 -0.143 -0.423 0.137 1325 2.87 -0.287 -0.567 -0.007 1335 2.48 -0.368 -0.648 -0.088 1345 2.40 -0.385 -0.665 -0.105 1355 2.36 -0.392 -0.672 -0.112 1365 2.76 -0.309 -0.589 -0.029 1375 2.59 -0.344 -0.624 -0.064 1385 1.51 -0.570 -0.850 -0.290 1395 1.34 -0.606 -0.886 -0.326 1405 1.83 -0.504 -0.784 -0.224 1415 1.36 -0.602 -0.882 -0.322 1425 2.30 -0.405 -0.685 -0.125 1435 1.50 -0.572 -0.852 -0.292 1445 1.26 -0.624 -0.904 -0.344 1455 1.49 -0.574 -0.854 -0.294 1465 2.42 -0.380 -0.660 -0.100 1475 1.19 -0.637 -0.917 -0.357 1485 2.21 -0.423 -0.703 -0.143 1495 1.88 -0.494 -0.774 -0.214 1505 1.47 -0.578 -0.858 -0.298 1515 1.50 -0.572 -0.852 -0.292 1525 1.14 -0.648 -0.928 -0.368 1535 1.26 -0.623 -0.903 -0.343 1545 1.36 -0.603 -0.883 -0.323 1555 1.19 -0.637 -0.917 -0.357 1565 1.71 -0.528 -0.808 -0.248 1575 1.71 -0.528 -0.808 -0.248 1585 1.71 -0.529 -0.809 -0.249 1595 1.18 -0.639 -0.919 -0.359 1605 1.55 -0.561 -0.841 -0.281 1615 2.18 -0.430 -0.710 -0.150 1625 1.91 -0.487 -0.767 -0.207 1635 1.35 -0.603 -0.883 -0.323 1645 1.91 -0.486 -0.766 -0.206 1655 1.77 -0.516 -0.796 -0.236 1665 1.65 -0.541 -0.821 -0.261 1675 2.29 -0.408 -0.688 -0.128 1685 1.60 -0.552 -0.832 -0.272 1695 1.74 -0.523 -0.803 -0.243 1705 1.67 -0.538 -0.818 -0.258 1715 1.60 -0.551 -0.831 -0.271 1725 1.36 -0.602 -0.882 -0.322 1735 2.08 -0.452 -0.732 -0.172 1745 1.99 -0.471 -0.751 -0.191 1755 1.88 -0.494 -0.774 -0.214 1765 2.29 -0.407 -0.687 -0.127 1775 2.26 -0.413 -0.693 -0.133 1785 2.34 -0.397 -0.677 -0.117 1795 2.06 -0.455 -0.735 -0.175 1805 2.93 -0.275 -0.555 0.005 1815 2.67 -0.327 -0.607 -0.047 1825 2.93 -0.273 -0.553 0.007 1835 3.06 -0.247 -0.527 0.033 1845 2.51 -0.361 -0.641 -0.081 1855 3.15 -0.227 -0.507 0.053 1865 2.82 -0.296 -0.576 -0.016 1875 2.39 -0.387 -0.667 -0.107 1885 3.54 -0.146 -0.426 0.134 1895 2.96 -0.267 -0.547 0.013 1905 3.62 -0.130 -0.410 0.150 1915 3.71 -0.111 -0.391 0.169 1925 3.72 -0.109 -0.389 0.171 1935 3.62 -0.129 -0.409 0.151 1945 4.30 0.013 -0.267 0.293 1955 3.44 -0.168 -0.448 0.112 1965 3.81 -0.089 -0.369 0.191 1975 3.63 -0.128 -0.408 0.152 1985 4.35 0.024 -0.256 0.304 1995 5.16 0.192 -0.088 0.472