Lake Victoria High-Resolution Diatom-Based Conductivity Reconstruction ----------------------------------------------------------------------- World Data Center for Paleoclimatology, Boulder and NOAA Paleoclimatology Program ----------------------------------------------------------------------- NOTE: PLEASE CITE CONTRIBUTORS WHEN USING THIS DATA!!!!! NAME OF DATA SET: Lake Victoria High-Resolution Diatom-Based Conductivity Reconstruction LAST UPDATE: 5/2005 (Original receipt by WDC Paleo) CONTRIBUTORS: J. Curt Stager, David Ryves, Brian F. Cumming, L. David Meeker, Juerg Beer IGBP PAGES/WDCA CONTRIBUTION SERIES NUMBER: 2005-040 SUGGESTED DATA CITATION: Stager, J.C., et al. 2005. Lake Victoria High-Resolution Diatom-Based Conductivity Reconstruction. IGBP PAGES/World Data Center for Paleoclimatology Data Contribution Series # 2005-040. NOAA/NCDC Paleoclimatology Program, Boulder CO, USA. ORIGINAL REFERENCE: Stager, J.C., D. Ryves, B.F. Cumming, L.D. Meeker, and J. Beer. 2005. Solar variability and the levels of Lake Victoria, East Africa, during the last millenium. Journal of Paleolimnology, Volume 33, Issue 2, Feb. 2005, pp. 243-251. ABSTRACT: A new diatom series with 1–6 year resolution from Lake Victoria, East Africa, shows that lake level minima occurred ca. 820–760, 680–660, 640–620, 370–340, and 220–150 calendar years BP. Inferred lake levels were exceptionally high during most of the Little Ice Age (ca. 600–200 calendar years BP). Synchrony between East African high lake levels and prolonged sunspot minima during much of the last millenium may reflect solar variability's effects on tropical rainfall, but those relationships reversed sign ca. 200 years ago. Historical records also show that Victoria lake levels rose during every peak of the ca. 11-year sunspot cycle since the late 19th century. These findings suggest that, if these apparent tropical sun–climate associations during the last millenium were real, then they were subject to abrupt sign reversals. GEOGRAPHIC REGION: East Africa PERIOD OF RECORD: ~1000 - 1970 AD DESCRIPTION: Lake Victoria High-Resolution Diatom-Based Conductivity Reconstruction. Shallow water diatom percentage and inferred conductivity, interpreted as a proxy for lake level over the last millennia. Core Location: Pilkington Bay, Lake Victoria, Uganda 0 deg. 17' N, 33 deg. 19' E, 1134m. elevation, water depth 8m. DATA: Column 1: Depth, cm. Column 2: Age, calendar years before 2000 A.D. Column 3: Percent shallow-water diatoms (SWD) Column 4: Inferred conductivity (uS/cm) Depth Age SWD cond 0.5 29 19.01 134.31 1.5 30 16.51 122.97 2.5 31 17.9 120.42 3.5 32 19.2 116.25 4.5 33 19.36 120.67 5.5 34 17.51 122.38 6.5 35 22.28 121.51 7.5 37 17.32 111.84 8.5 39 22.05 131.16 9.5 41 33.26 143.52 10.5 43 38.44 180.34 11.5 45.5 34.46 165.04 12.5 48 32.33 134.03 13.5 51 37.84 158.16 14.5 54 35.46 153.74 15.5 57 62.72 252.99 16.5 60 47.37 179.47 17.5 63 45.55 164.93 19.5 66.5 59.57 260.32 20.5 70 58.85 244.17 21.5 73.5 57.88 217.47 22.5 77 61.28 240.21 23.5 80.5 57.87 218.68 24.5 84 40.89 165.16 25.5 87.5 47.35 180.97 26.5 91.5 37.92 157.43 27.5 95.5 41.19 170.92 28.5 99.5 48.65 173.34 29.5 104 53.64 212.76 30.5 108.5 48.64 191.78 31.5 113.5 54.35 199.43 32.5 118.5 39.8 160.36 33.5 124 53.72 176.73 34.5 129.5 44.6 164.06 35.5 135 58.35 218.32 37.5 140.5 62.79 253.45 38.5 146 65.53 257.63 39.5 151.5 67.76 233.94 40.5 157 51.01 174.58 41.5 162.5 66.95 254.1 42.5 168 65.24 233.67 43.5 173.5 65.93 243.05 44.5 179 52.79 189.85 45.5 184.5 73.35 319.74 46.5 190 73.27 287.81 47.5 195.5 66.6 267.67 48.5 201 48.74 169.16 49.5 206.5 69.69 277.78 50.5 212 71.49 313.04 51.5 217.5 69.48 279.64 52.5 223 38.08 139.35 53.5 228.5 46.09 168.19 54.5 234 48.56 195.03 55.5 239.5 38.03 150.04 56.5 245 27.48 129.69 57.5 250.7 33.12 136.18 58.5 256.4 34.9 160.77 59.5 262.2 32.53 151.39 60.5 268 20.5 104.42 61.5 273.9 34.72 154.1 62.5 279.8 22.93 134.18 63.5 285.8 36.48 165.35 64.5 291.8 29.44 123.4 65.5 298 39.69 131.67 66.5 304.2 43.89 152.23 67.5 310.4 46.67 145.55 68.5 316.6 32.93 110.38 70.5 329 43.11 148.8 71.5 335.2 47.76 182.98 72.5 341.4 32.2 114.63 73.5 347.6 59.12 211.98 74.5 353.8 50.99 212.08 75.5 360 52.66 207.35 76.5 366.2 37.98 142.92 77.5 372.4 49.73 204.08 78.5 378.6 40.42 169.43 79.5 384.8 32.44 204.13 80.5 391 36.79 177.21 81.5 397.2 25.92 140.48 82.5 403.4 20.77 128.94 83.5 409.6 19 125.92 84.5 415.8 13.35 139.16 85.5 422 19.08 116.14 86.5 428.2 15.9 126.65 87.5 434.4 14.04 120.14 88.5 440.6 9.72 106.29 89.5 446.8 7.28 89.31 90.5 453 13.67 113.58 91.5 459.2 12.53 108.22 92.5 465.4 10.99 141.61 93.5 471.6 14.75 99.15 94.5 477.8 15.35 107.75 95.5 484 12.31 89.35 96.5 490.2 11.46 106.24 97.5 496.4 14.73 106.56 98.5 502.6 12.11 92.58 99.5 508.8 15.01 107.35 100.5 515 13.77 128.85 101.5 521.2 17.49 127.73 102.5 527.4 10.53 118.39 103.5 533.6 10.63 120.2 104.5 539.8 18.06 150.18 105.5 546 10.48 108.54 106.5 552.2 27.76 169.82 107.5 558.4 18.58 113.76 108.5 564.6 18.55 123.54 109.5 570.8 19.74 122.26 110.5 577 19.53 107.2 111.5 583.2 22.79 104.06 112.5 589.4 31.35 144.28 113.5 595.6 26.24 123.31 114.5 601.8 24.18 121.81 115.5 608 43.17 178.16 116.5 614.2 59.6 265.52 117.5 620.4 56.92 230.41 118.5 626.6 56.18 250.73 119.5 632.8 53.23 222.69 120.5 639 25.64 132.1 121.5 645.2 27.06 139.25 122.5 651.4 55.62 266.5 123.5 657.6 50.89 212.32 124.5 663.8 59.6 277.14 125.5 670 49.25 200.72 126.5 676.2 50.1 218.98 127.5 682.4 41.22 166 128.5 688.6 44.55 187.37 129.5 694.8 48.74 200.82 130.5 701 42.65 193.51 131.5 707.2 41.84 171.51 132.5 713.4 38.76 169.2 133.5 719.6 44.68 190.9 134.5 725.8 45.82 208.93 135.5 732 49.18 210.96 136.5 738.2 43.58 199.25 137.5 744.4 53.79 211.45 138.5 750.6 44.62 185.87 139.5 756.8 55.13 217.17 140.5 763 58.1 222.38 141.5 769.2 58.3 229.61 142.5 775.4 55.4 235.29 143.5 781.6 57.64 241.77 144.5 787.8 60.84 258.05 145.5 794 63.56 259.12 146.5 800.2 64.23 243.56 147.5 806.4 57.78 211.54 148.5 812.6 61.26 260.68 149.5 818.8 45.44 161.88 150.5 825 43.66 173.98 151.5 831.2 47.99 180.8 152.5 837.4 46.9 198.66 153.5 843.6 43.86 166 154.5 849.8 42.47 175.51 155.5 856 40.63 171.24 156.5 862.2 39.78 166.57 157.5 868.4 46.78 169.47 158.5 874.6 47.79 174.74 159.5 880.8 46.25 187.59 160.5 887 42.99 161.29 161.5 893.2 47.14 195.88 162.5 899.4 41.4 156.64 163.5 905.6 43.19 184.16 164.5 911.8 49.58 203.42 165.5 918 40.36 177.05 166.5 924.2 46.41 185.52 167.5 930.4 45.35 178.85 168.5 936.6 42.57 164.78 169.5 942.8 39.22 157.04 170.5 949 41.94 165.16 171.5 955.2 38.99 158.82 172.5 961.4 41.13 163.91 173.5 967.6 44.98 169.43