Lake Challa, East Africa 25KYr Leaf Wax Deuterium Data ----------------------------------------------------------------------- World Data Center for Paleoclimatology, Boulder and NOAA Paleoclimatology Program ----------------------------------------------------------------------- NOTE: PLEASE CITE ORIGINAL REFERENCE WHEN USING THIS DATA!!!!! NAME OF DATA SET: Lake Challa, East Africa 25KYr Leaf Wax Deuterium Data LAST UPDATE: 4/2011 (Original receipt by WDC Paleo) CONTRIBUTORS: Tierney, J.E., J.M. Russell, J.S. Sinninghe Damsté, Y. Huang, and D. Verschuren. IGBP PAGES/WDCA CONTRIBUTION SERIES NUMBER: 2011-047 WDC PALEO CONTRIBUTION SERIES CITATION: Tierney, J.E., et al. 2011. Lake Challa, East Africa 25KYr Leaf Wax Deuterium Data. IGBP PAGES/World Data Center for Paleoclimatology Data Contribution Series # 2011-047. NOAA/NCDC Paleoclimatology Program, Boulder CO, USA. ORIGINAL REFERENCE: Tierney, J.E., J.M. Russell, J.S. Sinninghe Damsté, Y. Huang, and D. Verschuren. 2011. Late Quaternary behavior of the East African monsoon and the importance of the Congo Air Boundary. Quaternary Science Reviews, Vol. 30 (7-8), pp. 798-807. doi:10.1016/j.quascirev.2011.01.017 ABSTRACT: Both Atlantic and Indian Ocean climate dynamics exert influence over tropical African hydroclimate, producing complex patterns of convergence and precipitation. To isolate the Indian Ocean influence on African paleohydrology, we analyzed the deuterium/ hydrogen ratio of higher plant leaf waxes (dDwax) in a 25 000-year sediment record from Lake Challa (3°S, 38° E) in the easternmost area of the African tropics. Whereas both the seismic record of inferred lake level fluctuations and the Branched and Isoprenoidal Tetraether (BIT) index proxy record changes in hydrology within the Challa basin, dDwax, as a proxy for the isotopic composition of precipitation (dDP) is interpreted as a tracer of large-scale atmospheric circulation that integrates the history of the moisture transported to the Lake Challa area. Specifically, based on modern- day isotope-rainfall relationships, we argue that Lake Challa dDwax reflects the intensity of East African monsoon circulation. The three hydrological proxy records show generally similar trends for the last 25 000 years, but there are important differences between them, primarily during the middle Holocene. We interpret this deviation of dDwax from local hydrological history as a decoupling of East African monsoon intensity - which heavily influences the isotopes of precipitation in East Africa today - from rainfall amount in the Challa basin. In combination, the hydrological proxy data from Lake Challa singularly highlight zonal gradients in tropical African climate that occur over a variety of timescales, suggesting that the Congo Air Boundary plays a fundamental role in controlling hydroclimate in the African tropics. ADDITIONAL REFERENCE: Verschuren, D., J.S. Sinninghe Damsté, J. Moernaut, I. Kristen, M. Blaauw, M. Fagot, G. Haug, and CHALLACEA project members. 2009. Half-precessional dynamics of monsoon rainfall near the East African Equator. Nature, Vol. 462, No. 7273, pp. 637-641. GEOGRAPHIC REGION: East Africa PERIOD OF RECORD: 25KYrBP - present FUNDING SOURCES: US National Oceanic and Atmospheric Administration (NOAA) grant NA090AR4310107, Dutch Organization for Scientific Research (NWO) and FWO-Vlaanderen (Belgium) CHALLACEA project. DESCRIPTION: Deuterium/hydrogen ratio of higher plant leaf waxes (dDwax) from Lake Challa, Kenya, covering the last 25,000 years. The chronology for the Lake Challa composite sediment sequence is based on a combination of 210Pb and AMS 14C dating as previously described by Verschuren et al. (2009). The composite sedimentary sequence was sampled every 4 cm down to a depth of 200 cm to generate a high-resolution (30-50 year) record for the past two millennia, and then was sampled every 16 cm (~300 years) thereafter. Higher sampling resolution (~100 year) was also applied during the Younger Dryas interval. D/H composition of the C28 fatty acid samples (dDwax) was determined via gas chromatography-isotope-ratio mass spectrometry. Lake Challa, Kenya/Tanzania: 3°19'S, 37°42'E, 90m water depth. DATA: Tierney et al. 2011 Lake Challa C28 Leaf Wax dD data Column 1: Depth (cm) Column 2: Age (Year BP) Column 3: C28_dD (per mil) Column 4: C28_dDIV (per mil, ice volume corrected) Depth YearBP C28_dD C28_dDIV 2 -30 -108.8 -108.8 6 8 -103.7 -103.7 10 46 -103.5 -103.5 14 83 -101.2 -101.2 18 120 -106.1 -106.1 22 156 -110.7 -110.7 26 191 -108.4 -108.4 30 225 -108.4 -108.4 34 258 -109.5 -109.5 38 290 -106.8 -106.8 42 321 -106.6 -106.6 46 351 -106.2 -106.2 50 381 -104.3 -104.3 54 409 -102.6 -102.6 58 437 -99.1 -99.1 62 465 -105.1 -105.1 66 493 -101.0 -101.0 70 521 -101.2 -101.2 74 550 -99.7 -99.7 78 579 -101.5 -101.5 82 609 -98.8 -98.8 86 641 -99.2 -99.2 90 673 -104.1 -104.1 94 707 -106.3 -106.3 98 743 -104.9 -104.9 102 780 -103.4 -103.4 106 818 -104.2 -104.2 110 858 -102.9 -102.9 114 899 -105.2 -105.2 118 941 -102.1 -102.1 126 1028 -107.9 -107.9 130 1073 -108.6 -108.6 134 1118 -107.0 -107.0 138 1165 -103.4 -103.4 142 1211 -101.8 -101.7 146 1259 -100.3 -100.3 150 1307 -98.8 -98.8 154 1355 -101.6 -101.5 158 1404 -97.0 -96.9 162 1454 -101.9 -101.8 166 1504 -99.7 -99.6 170 1554 -101.5 -101.3 174 1605 -100.8 -100.7 178 1657 -97.1 -97.0 182 1709 -101.8 -101.6 186 1761 -108.2 -108.1 190 1814 -108.5 -108.3 194 1868 -108.6 -108.4 198 1922 -97.5 -97.3 202 1976 -98.0 -97.8 206 2031 -100.2 -100.0 218 2199 -100.4 -100.3 230 2370 -108.6 -108.5 242 2543 -110.2 -110.3 254 2713 -109.2 -109.3 266 2877 -107.8 -108.0 278 3032 -102.6 -102.9 290 3176 -100.9 -101.2 302 3313 -99.2 -99.5 338 3731 -91.8 -92.1 374 4261 -91.6 -91.9 398 4708 -108.6 -108.8 410 4932 -111.7 -111.9 434 5312 -105.2 -105.4 446 5473 -101.5 -101.8 470 5756 -114.3 -114.6 482 5888 -112.2 -112.5 518 5987 -113.0 -113.4 542 6265 -118.6 -119.0 578 6722 -112.6 -113.1 602 7042 -108.4 -109.0 650 7679 -112.7 -113.5 674 7978 -114.9 -115.7 722 8161 -119.2 -120.0 734 8313 -114.4 -115.2 746 8475 -114.4 -115.1 758 8655 -109.8 -110.5 782 9087 -111.2 -111.9 806 9596 -105.8 -106.8 818 9851 -105.4 -106.5 830 10088 -124.2 -125.4 842 10299 -113.0 -114.3 866 10641 -117.0 -118.4 890 10908 -121.4 -122.9 914 11135 -116.3 -118.1 926 11245 -113.9 -115.8 938 11360 -116.7 -118.7 950 11483 -119.2 -121.4 958 11572 -114.9 -117.3 962 11619 -107.1 -109.5 966 11667 -108.0 -110.4 974 11768 -93.2 -95.9 986 11928 -94.4 -97.3 1010 12271 -81.1 -84.3 1034 12625 -84.3 -87.6 1046 12801 -102.3 -105.7 1050 12858 -109.1 -112.6 1058 12972 -113.8 -117.3 1070 13140 -97.6 -101.3 1082 13307 -106.3 -110.1 1106 13649 -105.1 -109.2 1130 14008 -110.4 -114.8 1142 14196 -108.4 -113.0 1154 14390 -107.0 -111.8 1166 14589 -105.4 -110.3 1178 14791 -101.3 -106.5 1190 14995 -101.2 -106.6 1202 15197 -100.1 -105.7 1226 15590 -104.3 -110.3 1238 15776 -104.0 -110.2 1262 16116 -95.9 -102.5 1286 16407 -88.6 -95.4 1310 16660 -91.4 -98.4 1334 16891 -114.8 -121.7 1358 17112 -102.2 -109.3 1382 17332 -99.1 -106.3 1406 17554 -101.7 -109.1 1430 17778 -102.7 -110.2 1454 18005 -98.6 -106.3 1478 18235 -98.7 -106.4 1514 18578 -100.6 -108.1 1550 18907 -96.7 -104.1 1586 19223 -91.8 -99.3 1622 19588 -96.6 -104.1 1658 20003 -105.2 -112.7 1694 20363 -96.7 -104.1 1730 20579 -98.3 -105.6 1766 20712 -103.3 -110.6 1802 20896 -102.4 -109.6 1850 21369 -109.6 -116.7 1874 21679 -107.7 -114.8 1898 22014 -106.0 -113.0 1934 22337 -112.0 -118.9 1970 22802 -111.9 -118.8 2006 23226 -108.7 -115.6 2018 23367 -106.6 -113.4 2054 23573 -110.5 -117.3 2090 24015 -91.4 -98.2 2126 24459 -114.0 -120.7 2162 24922 -114.2 -120.9