# Gulf of Aden 2000 Year Leaf Wax Isotope, TEX86, and SST Data #----------------------------------------------------------------------- # World Data Service for Paleoclimatology, Boulder # and # NOAA Paleoclimatology Program # National Centers for Environmental Information (NCEI) #----------------------------------------------------------------------- # # NOTE: Please cite original publication, online resource and date accessed when using this data. # If there is no publication information, please cite Investigator, title, online resource and date accessed. # # Description/Documentation lines begin with # # Data lines have no # # # Online_Resource: https://www.ncdc.noaa.gov/paleo/study/19200 # Online_Resource: http://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/tierney2015b/tierney2015bc1.txt # # Archive: Paleoceanography # # Parameter_Keywords: biomarkers, carbon isotopes #--------------------------------------- # Contribution_Date # Date: 2015-10-09 #--------------------------------------- # Title # Study_Name: Gulf of Aden 2000 Year Leaf Wax Isotope, TEX86, and SST Data #--------------------------------------- # Investigators # Investigators: Tierney, J.E.; Ummenhofer, C.C.; deMenocal, P.B. #--------------------------------------- # Description and Notes # Description: Gulf of Aden leaf wax isotope (dDwax and d13Cwax), TEX86 biomarker proxy data, and SST reconstruction # from 2 cores spanning the past ca. 2000 years. Also included are chronologies for both cores P178-15P and P178-BC1. # Note that the updated chronology of P178-15P supersedes the previous chronology published by Tierney and deMenocal, 2013 # (https://www.ncdc.noaa.gov/paleo/study/15537). # Provided Keywords: Horn of Africa, African climate, aridity #--------------------------------------- # Publication # Authors: Jessica E. Tierney, Caroline C. Ummenhofer, and Peter B. deMenocal # Published_Date_or_Year: 2015-10-09 # Published_Title: Past and future rainfall in the Horn of Africa # Journal_Name: Science Advances # Volume: 1 # Issue: 9 # Pages: # Report Number: e1500682 # DOI: 10.1126/sciadv.1500682 # Online_Resource: http://advances.sciencemag.org/content/1/9/e1500682.abstract # Full_Citation: # Abstract: The recent decline in Horn of Africa rainfall during the March-May "long rains" season has fomented drought and famine, threatening food security in an already vulnerable region. Some attribute this decline to anthropogenic forcing, whereas others maintain that it is a feature of internal climate variability. We show that the rate of drying in the Horn of Africa during the 20th century is unusual in the context of the last 2000 years, is synchronous with recent global and regional warming, and therefore may have an anthropogenic component. In contrast to 20th century drying, climate models predict that the Horn of Africa will become wetter as global temperatures rise. The projected increase in rainfall mainly occurs during the September-November "short rains" season, in response to large-scale weakening of the Walker circulation. Most of the models overestimate short rains precipitation while underestimating long rains precipitation, causing the Walker circulation response to unrealistically dominate the annual mean. Our results highlight the need for accurate simulation of the seasonal cycle and an improved understanding of the dynamics of the long rains season to predict future rainfall in the Horn of Africa. #--------------------------------------- # Funding_Agency # Funding_Agency_Name: US National Science Foundation # Grant: OCE-1203892 #--------------------------------------- # Site Information # Site_Name: P178-15P # Location: Ocean>Indian Ocean>Arabian Sea # Country: # Northernmost_Latitude: 11.955 # Southernmost_Latitude: 11.955 # Easternmost_Longitude: 44.3 # Westernmost_Longitude: 44.3 # Elevation: -869 #--------------------------------------- # Data_Collection # Collection_Name: Tierney2015BC1 # Earliest_Year: 1628 # Most_Recent_Year: 2000 # Time_Unit: AD # Core_Length: 0.405 # Notes: #--------------------------------------- # Chronology: # This chronology describes the 14C dates on core P178-BC1. Calibrated ages are derived from OxCal 4.2 and incorporate constraints on possible sedimentation # rates provided by the 210Pb data. Also included are the prior and posterior estimates of the local DeltaR value (deviation from global mean reservoir correction). # # Labcode depth_top depth_bottom material.dated 14Cage.raw 14Cage.raw_err datemeth reservoirCorr delta-R_prior delta-R_1sig_prior delta-R_posterior delta-R_1sig_posterior calib.14C calib.14C_1sig calib_method rejected notes # OS-101661 15 16 G. ruber (white) 700 25 14C AMS Marine13 300 100 311 24 1890 11 OxCal 4.2 no # OS-110256 20 21 G. ruber (white) 800 25 14C AMS Marine13 300 100 311 24 1835 17 OxCal 4.2 no # OS-110257 25 26 G. ruber (white) 860 20 14C AMS Marine13 300 100 311 24 1781 23 OxCal 4.2 no # OS-101815 30 31 G. ruber (white) 895 20 14C AMS Marine13 300 100 311 24 1726 27 OxCal 4.2 no # OS-110258 35 36 G. ruber (white) 975 20 14C AMS Marine13 300 100 311 24 1674 30 OxCal 4.2 no # OS-101816 40 41 G. ruber (white) 1000 20 14C AMS Marine13 300 100 311 24 1628 35 OxCal 4.2 no # # # This chronology describes the 210Pb dates on core P178-BC1. 210Pb dating was achieved by gamma counting. We estimated background (supported) 210Pb from the average of # the measurements taken at 16.5 cm and 26.5 cm, which were identical within error. Sedimentation rate was deemed relatively constant with the exception of an apparent # inversion between 3.25-5.5 cm, possibly due to diagenetic alteration. We excluded these inverted data from subsequent calculations of sedimentation rates. # We used a Monte Carlo procedure to propagate uncertainties related to both the calculation of "excess" (unsupported) Pb and analytical uncertainties. # The quoted 1-sigma errors are derived from this Monte Carlo procedure. Please see the original publication for further details. # # Lab depth_top depth_bottom Pb210 Pb210_err_1sig Pb210_xs age age_err_1s rejected notes # WHOI 0 0.5 0.227 0.008 0.197 2000 0 no # WHOI 0.5 1 0.216 0.010 0.186 1997 1 no # WHOI 1.5 2 0.179 0.005 0.149 1991 2 no # WHOI 2.5 3 0.163 0.005 0.133 1986 4 no # WHOI 3 3.5 0.105 0.011 0.075 NaN NaN yes date rejected due to evidence for diagenetic imprint. See original publication for details # WHOI 3.5 4 0.121 0.007 0.091 NaN NaN yes date rejected due to evidence for diagenetic imprint. See original publication for details # WHOI 4 4.5 0.136 0.008 0.106 1977 6 no # WHOI 4.5 5 0.160 0.007 0.129 NaN NaN yes date rejected due to evidence for diagenetic imprint. See original publication for details # WHOI 5 6 0.143 0.010 0.112 NaN NaN yes date rejected due to evidence for diagenetic imprint. See original publication for details # WHOI 6 7 0.110 0.006 0.079 1964 9 no # WHOI 8 9 0.086 0.008 0.056 1953 11 no # WHOI 10 11 0.061 0.005 0.030 1942 14 no # WHOI 12 13 0.056 0.007 0.025 1931 17 no # WHOI 14 15 0.046 0.010 0.016 1919 19 no # WHOI 16 17 0.029 0.006 0.000 NaN NaN yes date not used because no significant excess Pb210 # WHOI 26 27 0.032 0.009 0.000 NaN NaN yes date not used because no significant excess Pb210 # #--------------------------------------- # Variables # Data variables follow that are preceded by "##" in columns one and two. # Variables list, one per line, shortname-tab-longname components (9 components: what, material, error, units, seasonality, archive, detail, method, C or N for Character or Numeric data) ## depth_cm depth,,,cm,,,,,N ## age_AD age,,,year AD,,,,,N ## dDwax hydrogen isotopic composition of higher plant leaf waxes (C30 n-acid),,,per mil vs. VSMOW,,Paleoceanography,,compound-specific isotope ratio mass spectrometry,N ## d13Cwax carbon isotopic composition of higher plant leaf waxes (C30 n-acid),,,per mil vs. VPDB,,Paleoceanography,,compound-specific isotope ratio mass spectrometry,N ## tex86 tetraether index of 86 carbons,,,fraction from 0 to 1,,Paleoceanography,,high-performance liquid chromatography mass spectrometry,N ## sst median calibrated ssts from tex86,,,degrees Celsius,,Paleoceanography,,BAYSPAR Bayesian calibration (using BAYSPAR-NRS Tierney & Tingley 2014 GCA),N ## sst_1s_lower 1-sigma lower bound on ssts,,,degrees Celsius,,Paleoceanography,,BAYSPAR Bayesian calibration,N ## sst_1s_upper 1-sigma upper bound on ssts,,,degrees Celsius,,Paleoceanography,,BAYSPAR Bayesian calibration,N #------------------------ # Data # Data lines follow (have no #) # Data line format - tab-delimited text, variable short name as header # Missing Value: NaN depth_cm age_AD dDwax d13Cwax tex86 sst sst_1s_lower sst_ls_upper 0.25 2000 -122.7 -25.14 0.708 27.99 27.32 28.82 0.75 1997 -123.5 -24.88 0.709 28.09 27.39 28.91 1.25 1994 -123.5 -24.79 0.710 28.14 27.44 28.94 1.75 1991 -123.5 -25.23 0.707 27.91 27.26 28.69 2.25 1988 -126.3 -25.33 0.707 27.95 27.26 28.74 2.75 1985 -125.4 -25.29 0.710 28.13 27.46 28.89 3.25 1982 -125.0 -25.10 0.712 28.22 27.56 28.99 3.75 1979 -126.7 -24.97 0.713 28.33 27.65 29.19 4.25 1976 -125.3 -25.11 0.712 28.18 27.50 29.00 4.75 1973 -124.8 -25.11 0.704 27.83 27.16 28.64 5.5 1968 -126.1 -25.08 0.704 27.75 27.06 28.55 6.5 1961 -126.9 -25.01 0.702 27.62 26.99 28.39 7.5 1954 -128.9 -25.01 0.700 27.49 26.84 28.26 8.5 1947 -128.6 -24.87 0.701 27.56 26.90 28.37 9.5 1940 -130.0 -24.91 0.701 27.56 26.91 28.37 10.5 1933 -126.8 -24.66 0.700 27.47 26.81 28.27 11.5 1925 -128.6 -24.49 0.704 27.75 27.10 28.55 12.5 1917 -130.8 -24.52 0.698 27.36 26.71 28.15 13.5 1908 -129.4 -24.52 0.697 27.28 26.64 28.03 14.5 1899 -129.0 -24.63 0.698 27.36 26.69 28.13 15.5 1890 -131.1 -24.42 0.691 26.96 26.23 27.69 16.5 1879 -130.9 -24.34 0.698 27.35 26.65 28.12 17.5 1868 -132.6 -24.20 0.695 27.20 26.54 27.99 18.5 1857 -133.7 -24.26 0.701 27.55 26.92 28.31 19.5 1846 -134.6 -24.30 0.699 27.45 26.81 28.32 20.5 1835 -134.4 -24.35 0.693 27.04 26.38 27.87 21.5 1824 -133.7 -24.21 0.693 27.02 26.37 27.81 22.5 1814 -133.7 -24.33 0.693 27.12 26.46 27.90 23.5 1803 -133.3 -24.53 0.697 27.39 26.74 28.13 24.5 1792 -131.9 -24.45 0.694 27.17 26.52 28.00 25.5 1781 -132.7 -24.40 0.696 27.20 26.51 27.99 26.5 1770 -132.4 -24.30 0.698 27.43 26.75 28.22 27.5 1759 -131.8 -24.25 0.693 27.10 26.39 27.90 28.5 1748 -131.9 -24.56 0.697 27.30 26.66 28.16 29.5 1737 -132.3 -24.39 0.696 27.34 26.68 28.15 30.5 1726 -135.0 -24.46 0.698 27.40 26.73 28.24 31.5 1715 -133.9 -24.66 0.693 27.10 26.39 27.87 32.5 1705 -134.6 -24.50 0.695 27.12 26.49 27.92 33.5 1694 -134.9 -24.37 0.696 27.30 26.64 28.13 34.5 1684 -135.2 -24.47 0.698 27.34 26.70 28.14 35.5 1674 -135.6 -24.26 0.696 27.28 26.61 28.02 36.5 1665 -136.1 -24.38 0.699 27.48 26.77 28.22 37.5 1655 -135.8 -24.59 0.696 27.22 26.59 28.00 38.5 1646 -136.7 -24.50 0.696 27.34 26.66 28.08 39.5 1637 -137.8 -24.58 0.695 27.17 26.46 27.99 40.5 1628 -135.8 -24.49 0.700 27.52 26.83 28.27