Florida Straits 20KYr Mg/Ca SST and d18Osw Reconstructions ----------------------------------------------------------------------- World Data Center for Paleoclimatology, Boulder and NOAA Paleoclimatology Program ----------------------------------------------------------------------- NOTE: PLEASE CITE ORIGINAL REFERENCE WHEN USING THIS DATA!!!!! NAME OF DATA SET: Florida Straits 20KYr Mg/Ca SST and d18Osw Reconstructions LAST UPDATE: 10/2011 (Original receipt by WDC Paleo) CONTRIBUTORS: Schmidt, M.W. and J. Lynch-Stieglitz IGBP PAGES/WDCA CONTRIBUTION SERIES NUMBER: 2011-138 WDC PALEO CONTRIBUTION SERIES CITATION: Schmidt, M.W. and J. Lynch-Stieglitz. 2011. Florida Straits 20KYr Mg/Ca SST and d18Osw Reconstructions. IGBP PAGES/World Data Center for Paleoclimatology Data Contribution Series # 2011-138. NOAA/NCDC Paleoclimatology Program, Boulder CO, USA. ORIGINAL REFERENCE: Schmidt, M.W. and J. Lynch-Stieglitz. 2011. Florida Straits deglacial temperature and salinity change: Implications for tropical hydrologic cycle variability during the Younger Dryas. Paleoceanography, 26, PA4205, doi:10.1029/2011PA002157. ABSTRACT: The prevailing paradigm of abrupt climate change holds that rapid shifts associated with the most extreme climate swings of the last glacial cycle were forced by changes in the strength and northward extension of Atlantic Meridional Overturning Circulation (AMOC), resulting in an abrupt reorganization of atmospheric circulation patterns with global teleconnections. To determine the timing of tropical Atlantic atmospheric circulation changes over the past 21 ka BP, we reconstruct high resolution sea surface temperature and d18OSW (a proxy for surface salinity) records based on Mg/Ca ratios and oxygen isotope measurements in the planktonic foraminifera Globigerinoides ruber from a sediment core located on the western margin of the Florida Straits. As a proxy for meltwater discharge influence on Florida Straits surface water salinity, we also measured Ba/Ca ratios in G. ruber from the same core. Results show that riverine influence on Florida Straits surface water started by 17.2 ka BP and ended by 13.6 ka BP, 600 years before the start of the Younger Dryas (YD) cold interval. The initiation of the YD is marked by an abrupt increase in Florida Straits d18OSW values, indicating a shift to elevated sea surface salinity occurring in 130 years, most likely resulting from increased regional aridity and/or reduced precipitation. In order to resolve the timing of tropical atmospheric circulation change relative to AMOC variability across this transition, we compare the timing of surface water changes to a recently published record of Florida Current variability in the same core reconstructed from benthic oxygen isotope measurements. We find synchronous changes in atmospheric and ocean circulation on the transition into the YD, consistent with an abrupt reduction in AMOC as the driver of tropical Atlantic atmospheric circulation change at this time. GEOGRAPHIC REGION: Western Tropical Atlantic PERIOD OF RECORD: 20 KYrBP - present FUNDING SOURCES: US National Science Foundation (NSF) grants OCE-0823498, OCE-0648258, and OCE-0096472, US National Oceanic and Atmospheric Administration (NOAA) Global Change Postdoctoral Fellowship. DESCRIPTION: To determine the timing of tropical Atlantic atmospheric circulation changes over the past 20 ka BP, we reconstruct high resolution sea surface temperature and d18OSW (a proxy for surface salinity) records based on Mg/Ca ratios and oxygen isotope measurements in the planktonic foraminifera Globigerinoides ruber from a sediment core located on the western margin of the Florida Straits. As a proxy for meltwater discharge influence on Florida Straits surface water salinity, we also measured Ba/Ca ratios in G. ruber from the same core. The age model for this core is based on calibrated radiocarbon dates from G. ruber and G. sacculifer. Core KNR166-2-26JPC: 24°19.61'N, 83°15.14'W, 546 m water depth. DATA: 1. Table 1. Twenty-Six JPC Radiocarbon Dates *a Depth(cm) Species 14C Age Error CalendarAge Error(+/-yr) 0.75 G. sacculifer 1070 70 635 118 48.25 G. sacculifer 2990 30 2772 66 112.25 G. sacculifer 6720 40 7250 95 144.25 G. sacculifer 8100 80 8613 229 216.25 G. sacculifer 9550 40 10398 121 280.25 G. sacculifer, G. ruber 10100 45 11115 94 344.25 G. sacculifer 10000 110 10913 *b 275 356.25 G. sacculifer 11750 95 13190 *b 217 364.25 G. sacculifer, G. ruber 10600 70 11795 *b 384 374.25 G. sacculifer 10500 50 11643 *b 268 392.25 G. ruber 10850 65 12337 *b 236 408.25 G. sacculifer, G. ruber 10300 60 11392 *b 229 442.25 G. sacculifer, G. ruber 10700 65 12095 251 464.25 G. sacculifer, G. ruber 10800 55 12278 249 544.25 G. sacculifer, G. ruber 11000 65 12505 154 592.25 G. ruber 11400 65 12880 199 606.25 G. sacculifer 11600 35 13064 156 648.25 G. sacculifer 12350 200 13885 583 704.25 G. ruber 13500 55 15834 615 752.25 G. ruber 15550 70 18326 297 848.25 G. ruber 20300 120 23776 419 a* Calibrated using Calib 6.0 and Marine09 curve with a 400 year surface reservoir age. b* Not used in age model. 2. KNR166-2-26JPC Mg/Ca SST and d18Osw Column 1: Depth (cm) Column 2: Age (KYrBP) Column 3: G.ruber d18Oc (per mil VPDB) Column 4: d18Oc, global ice volume free correction (per mil VPDB) Column 5: Mg/Ca (mmol/mol) Column 6: SST (°C) Column 7: d18Osw, global ice volume free correction (per mil SMOW) Column 8: Ba/Ca (mmol/mol) Depth Age G.rub18Oc IVF-d18Oc Mg/Ca SST IVF-d18Osw Ba/Ca 0.75 0.64 4.57 27.6 0.91 8.25 0.97 4.36 27.1 0.88 32.25 2.04 4.78 28.1 0.9 48.25 2.76 4.28 26.9 0.87 56.25 3.32 4.76 28.1 64.25 3.88 4.98 28.6 0.95 72.25 4.44 5.05 28.7 0.97 80.25 5.01 4.33 27 0.95 88.25 5.57 4.16 26.6 0.92 96.25 6.13 -1.71 -1.7 4.4 27.2 0.79 0.98 103.25 6.62 -1.95 -1.95 112.25 7.25 -1.66 -1.73 1 120.25 7.58 -1.48 -1.56 124.25 7.75 -0.74 -0.82 128.25 7.91 -1.74 -1.83 0.98 136.25 8.24 -1.51 -1.63 0.98 144.25 8.58 -1.73 -1.89 4.86 28.3 0.83 0.98 152.25 8.78 -1.37 -1.56 4.57 27.6 1.02 1 166.25 9.14 -1.43 -1.67 4.03 26.3 0.62 176.25 9.39 -1.11 -1.38 4.89 28.4 1.36 1.06 184.25 9.6 -1.48 -1.77 4.32 27 0.68 192.25 9.8 -1.19 -1.5 4.19 26.7 0.88 0.98 208.25 10.21 -1.36 -1.72 1.01 216.25 10.42 -1.3 -1.68 1.09 224.25 10.51 -1.03 -1.42 3.73 25.4 0.69 1.13 232.25 10.6 -1.26 -1.66 4.47 27.4 0.86 1.09 240.25 10.69 -1.24 -1.66 4.43 27.3 0.85 1.04 248.25 10.77 -1.66 -2.09 4.65 27.8 0.53 1.11 256.25 10.86 -1.51 -1.94 4.17 26.6 0.42 0.97 264.25 10.95 -1.07 -1.52 4.57 27.6 1.06 1.13 272.25 11.04 -1.44 -1.9 4.25 26.8 0.51 1.02 280.25 11.13 -1.23 -1.7 1.03 288.25 11.18 -1.35 -1.82 296.25 11.22 -1.38 -1.85 4.16 26.6 0.51 1.03 304.25 11.27 -1.14 -1.62 0.98 312.25 11.32 -1.16 -1.64 4.32 27 0.81 0.93 319.25 11.36 -1.25 -1.73 4.06 26.3 0.57 0.97 322.25 11.38 -1.21 -1.7 4.33 27 0.75 0.95 324.25 11.39 -0.8 -1.29 4.85 28.3 1.42 1.07 326.25 11.4 -1.25 -1.74 4.53 27.5 0.82 1.08 328.25 11.41 -0.94 -1.43 4.27 26.9 0.99 1.02 330.25 11.42 -1.15 -1.64 4.28 26.9 0.79 1 332.25 11.43 -1.04 -1.53 4.07 26.3 0.77 1.04 334.25 11.45 -1.61 -2.1 4.09 26.4 0.22 1.01 336.25 11.46 -0.96 -1.46 1.05 338.25 11.47 -1.39 -1.89 4.39 27.2 0.6 1.06 340.25 11.48 -1.2 -1.7 4.14 26.5 0.65 1 342.25 11.49 -1.14 -1.64 1.09 344.25 11.5 -1.03 -1.53 3.86 25.8 0.66 1.09 346.25 11.52 -1.22 -1.72 3.61 25 0.31 0.97 348.25 11.53 -1.42 -1.92 3.77 25.5 0.21 0.94 350.25 11.54 -1.14 -1.64 3.99 26.1 0.62 1.03 352.25 11.55 -1.12 -1.62 354.25 11.56 -0.85 -1.35 3.75 25.4 0.77 0.93 356.25 11.57 -0.76 -1.27 0.96 358.25 11.59 -0.78 -1.29 4.06 26.3 1.02 0.92 360.25 11.6 -0.88 -1.39 3.95 26 0.85 0.98 362.25 11.61 -0.87 -1.38 4.19 26.7 1 0.95 364.25 11.62 -1.18 -1.69 4.17 26.6 0.68 1.05 366.25 11.63 -1.16 -1.67 4.13 26.5 0.68 0.92 368.25 11.64 -1.05 -1.56 4.43 27.3 0.95 370.25 11.66 -1.13 -1.64 0.9 372.25 11.67 -0.6 -1.11 0.98 374.25 11.68 -1.03 -1.54 4.47 27.4 0.99 0.98 376.25 11.69 -0.71 -1.22 3.84 25.7 0.95 378.25 11.7 -0.67 -1.17 3.95 26 1.07 1.12 380.25 11.71 -0.88 -1.39 4.14 26.5 0.96 0.89 382.25 11.73 -0.86 -1.36 4.5 27.5 1.18 384.25 11.74 -1 -1.51 4.22 26.7 0.89 0.98 386.25 11.75 -1.09 -1.6 0.89 388.25 11.76 -0.76 -1.27 4.05 26.3 1.02 0.88 390.25 11.77 -0.78 -1.29 4.3 26.9 1.14 392.25 11.78 -0.72 -1.23 4.33 27 1.22 1.09 394.25 11.8 -1.09 -1.61 4.36 27.1 0.86 1.26 396.25 11.81 -0.44 -0.95 4.09 26.4 1.37 0.91 398.25 11.82 -0.25 -0.76 3.84 25.7 1.41 0.92 400.25 11.83 -0.32 -0.84 4.46 27.4 1.68 1.12 402.25 11.84 -0.67 -1.19 4.46 27.4 1.34 0.85 404.25 11.85 -0.79 -1.31 0.93 406.25 11.87 -0.67 -1.19 4.2 26.7 1.2 0.92 408.25 11.88 -0.29 -0.82 4.2 26.7 1.57 0.9 410.25 11.89 -0.28 -0.8 4.22 26.7 1.59 0.96 412.25 11.9 -0.12 -0.65 3.68 25.2 1.43 414.25 11.91 -0.19 -0.72 3.86 25.8 1.47 1.03 416.25 11.93 -0.46 -0.99 3.94 26 1.25 418.25 11.94 -0.72 -1.25 422.25 11.96 -0.64 -1.17 3.94 26 1.07 0.91 424.25 11.97 -0.1 -0.63 4.07 26.3 1.68 426.25 11.98 -0.28 -0.81 3.92 25.9 1.42 0.91 428.25 12 -0.28 -0.8 3.96 26.1 1.45 0.94 430.25 12.01 -0.25 -0.78 4.03 26.2 1.51 432.25 12.02 -0.09 -0.62 3.63 25.1 1.43 0.85 434.25 12.03 0 -0.53 3.77 25.5 1.61 436.25 12.04 -0.17 -0.7 3.87 25.8 1.5 0.99 438.25 12.05 -0.15 -0.68 3.61 25 1.35 0.82 440.25 12.07 -0.19 -0.73 3.76 25.5 1.4 0.84 442.25 12.08 -0.24 -0.77 4.05 26.3 1.53 444.25 12.09 -0.5 -1.03 4 26.2 1.24 0.98 446.25 12.11 -0.17 -0.7 448.25 12.12 -0.18 -0.72 4.06 26.3 1.59 450.25 12.14 0.06 -0.48 3.81 25.6 1.68 0.96 452.25 12.16 -0.28 -0.82 3.96 26.1 1.43 454.25 12.17 -0.04 -0.58 3.31 24.1 1.25 0.86 456.25 12.19 0.01 -0.53 3.84 25.7 1.65 458.25 12.2 -0.27 -0.81 3.42 24.4 1.09 460.25 12.22 -0.18 -0.73 3.81 25.6 1.43 0.88 462.25 12.24 -0.52 -1.07 3.75 25.4 1.05 0.98 464.25 12.25 -0.17 -0.71 3.62 25 1.32 466.25 12.26 -0.22 -0.74 0.89 468.25 12.26 0.08 -0.44 0.79 470.25 12.27 0.28 -0.24 3.69 25.3 1.85 472.25 12.28 0.06 -0.46 3.79 25.6 1.69 0.89 474.25 12.28 -0.34 -0.86 3.66 25.2 1.21 476.25 12.29 -0.01 -0.53 3.71 25.3 1.56 478.25 12.3 -0.31 -0.83 3.69 25.3 1.26 480.25 12.3 -0.22 -0.74 4.07 26.3 1.56 482.25 12.31 -0.22 -0.74 3.59 25 1.29 484.25 12.32 -0.08 -0.6 3.99 26.1 1.66 486.25 12.32 -0.34 -0.87 3.56 24.9 1.14 488.25 12.33 0.11 -0.42 490.25 12.34 -0.1 -0.63 3.71 25.3 1.46 0.86 492.25 12.34 -0.12 -0.65 3.48 24.6 1.3 0.87 494.25 12.35 0.02 -0.51 3.76 25.5 1.62 496.25 12.36 -0.09 -0.62 3.83 25.7 1.56 498.25 12.36 0.02 -0.51 3.68 25.2 1.56 500.25 12.37 0.02 -0.51 502.25 12.38 -0.15 -0.68 3.88 25.8 1.52 504.25 12.38 -0.1 -0.63 3.7 25.3 1.46 506.25 12.39 -0.16 -0.69 508.25 12.4 -0.22 -0.75 510.25 12.4 -0.43 -0.96 3.88 25.8 1.24 512.25 12.41 -0.14 -0.67 3.63 25.1 1.38 514.25 12.42 0.1 -0.43 516.25 12.42 0.19 -0.34 3.6 25 1.69 518.25 12.43 0.1 -0.43 3.56 24.9 1.58 520.25 12.44 0.05 -0.48 522.25 12.44 -0.2 -0.73 3.57 24.9 1.28 1.04 524.25 12.45 0.05 -0.48 3.72 25.4 1.63 0.89 526.25 12.46 -0.11 -0.64 3.45 24.5 1.29 528.25 12.46 -0.06 -0.59 0.95 530.25 12.47 -0.14 -0.67 3.62 25 1.36 0.87 532.25 12.48 -0.55 -1.08 3.93 26 1.16 1.04 534.25 12.48 -0.14 -0.67 3.49 24.6 1.28 0.9 536.25 12.49 0.07 -0.46 3.73 25.4 1.65 0.95 538.25 12.5 -0.03 -0.56 540.25 12.5 -0.1 -0.63 3.6 25 1.4 0.94 542.25 12.51 -0.4 -0.93 544.25 12.52 0.22 -0.31 3.45 24.5 1.62 546.25 12.53 -0.04 -0.57 3.36 24.2 1.29 0.86 548.25 12.54 -0.25 -0.78 3.66 25.2 1.29 0.99 550.25 12.56 -0.32 -0.86 3.59 25 1.17 0.85 552.25 12.57 -0.53 -1.07 3.91 25.9 1.15 1.02 554.25 12.59 -0.11 -0.65 3.73 25.4 1.46 0.85 556.25 12.6 -0.08 -0.62 558.25 12.62 -0.02 -0.56 3.51 24.7 1.41 560.25 12.63 0.13 -0.41 3.54 24.8 1.58 562.25 12.64 -0.43 -0.97 564.25 12.66 -0.24 -0.78 3.47 24.6 1.17 0.9 566.25 12.67 -0.1 -0.64 3.75 25.4 1.47 568.25 12.69 -0.21 -0.75 3.58 24.9 1.26 570.25 12.7 -0.24 -0.78 3.29 24 1.04 0.84 572.25 12.72 -0.21 -0.75 3.55 24.8 1.24 574.25 12.73 -0.41 -0.95 576.25 12.74 -0.18 -0.73 578.25 12.76 -0.34 -0.89 3.73 25.4 1.22 1 580.25 12.77 -0.08 -0.63 3.56 24.9 1.38 582.25 12.79 -0.29 -0.84 3.79 25.5 1.29 0.92 584.25 12.8 -0.19 -0.75 3.32 24.1 1.09 1.09 586.25 12.82 -0.26 -0.82 588.25 12.83 -0.44 -1.01 3.62 25 1.02 0.95 590.25 12.84 0.04 -0.53 3.6 25 1.5 0.88 592.25 12.86 -0.17 -0.75 594.25 12.89 -0.4 -0.98 4.22 26.8 1.42 596.25 12.93 -0.55 -1.13 3.57 24.9 0.88 598.25 12.96 -0.89 -1.47 3.77 25.5 0.66 1.08 600.25 13 -0.31 -0.89 602.25 13.03 -0.76 -1.34 3.63 25.1 0.71 0.92 604.25 13.06 -1.21 -1.79 3.67 25.2 0.28 1.04 606.25 13.1 -1.14 -1.73 3.8 25.6 0.42 608.25 13.13 -1.23 -1.83 3.97 26.1 0.43 610.25 13.16 -0.94 -1.55 3.92 25.9 0.67 612.25 13.19 -1.12 -1.74 3.7 25.3 0.35 614.25 13.23 -0.95 -1.57 3.75 25.4 0.54 0.92 616.25 13.26 -0.78 -1.4 3.73 25.4 0.71 0.87 618.25 13.29 -0.96 -1.58 3.53 24.8 0.41 620.25 13.33 -1.01 -1.63 3.78 25.5 0.5 0.95 622.25 13.36 -0.79 -1.41 4.02 26.2 0.87 624.25 13.39 -0.98 -1.6 3.58 24.9 0.41 626.25 13.42 -0.71 -1.33 628.25 13.46 -0.92 -1.55 3.86 25.8 0.65 630.25 13.49 -1.06 -1.69 3.86 25.8 0.51 632.25 13.52 -1.34 -1.98 4.31 27 0.47 0.97 634.25 13.55 -0.67 -1.32 4.14 26.5 1.02 1.27 636.25 13.59 -0.74 -1.4 3.61 25 0.63 638.25 13.62 -0.74 -1.4 3.77 25.5 0.73 640.25 13.65 -0.74 -1.41 4.41 27.2 1.08 642.25 13.68 -0.49 -1.17 3.93 26 1.07 644.25 13.72 -0.54 -1.22 3.96 26 1.02 1.49 646.25 13.75 -0.57 -1.25 3.96 26 0.99 648.25 13.78 -0.71 -1.39 4.17 26.6 0.97 650.25 13.86 -0.81 -1.49 4.01 26.2 0.79 652.25 13.93 -0.74 -1.42 3.74 25.4 0.69 1.37 654.25 14 -0.51 -1.19 4.08 26.4 1.13 1.56 656.25 14.08 -1.09 -1.78 658.25 14.15 -0.97 -1.68 4.11 26.5 0.66 1.32 660.25 14.23 -1.75 4.1 26.4 -0.19 1.41 662.25 14.3 -0.42 -1.18 4.09 26.4 1.14 1.4 664.25 14.37 -0.84 -1.61 666.25 14.45 -0.87 -1.64 4.37 27.1 0.83 1.38 668.25 14.52 -0.52 -1.34 4.38 27.2 1.15 1.57 670.25 14.6 -0.94 -1.77 4.83 28.2 0.93 1.43 672.25 14.67 -0.83 -1.66 674.25 14.74 -0.57 -1.4 4.67 27.9 1.23 1.5 676.25 14.82 -0.31 -1.14 678.25 14.89 -0.73 -1.56 4.18 26.6 0.8 1.36 680.25 14.97 -0.94 -1.77 682.25 15.04 -0.33 -1.17 684.25 15.12 -0.74 -1.58 3.55 24.8 0.41 1 686.25 15.19 -0.53 -1.37 3.4 24.3 0.51 0.98 688.25 15.26 -0.93 -1.77 690.25 15.34 -0.07 -0.91 3.27 23.9 0.89 0.97 692.25 15.41 0.05 -0.79 3.59 25 1.24 1.11 694.25 15.49 -0.34 -1.18 4 26.2 1.1 1.13 696.25 15.56 -0.15 -0.99 698.25 15.63 0.07 -0.77 4.15 26.6 1.59 1.21 700.25 15.71 0.41 -0.43 4.21 26.7 1.95 1.35 702.25 15.78 0.27 -0.58 4.05 26.3 1.72 1.28 704.25 15.86 -0.16 -1.01 706.25 15.96 0.09 -0.76 3.78 25.5 1.37 1.21 708.25 16.06 0.62 -0.23 710.25 16.16 0.18 -0.67 3.93 26 1.57 1.41 712.25 16.26 0.37 -0.49 714.25 16.36 0.38 -0.48 716.25 16.46 -0.09 -0.95 3.99 26.1 1.31 1.31 718.25 16.56 0.37 -0.49 4.34 27.1 1.98 1.45 720.25 16.66 0.29 -0.57 722.25 16.76 0.39 -0.47 4.1 26.4 1.85 1.33 724.25 16.86 0.86 0 3.93 26 2.24 726.25 16.96 0.52 -0.34 3.84 25.7 1.84 1.67 729.25 17.11 0.62 -0.24 730.25 17.16 1.01 0.15 3.95 26 2.39 1.47 732.25 17.27 0.43 -0.43 734.25 17.37 1.05 0.19 3.13 23.4 1.89 1.08 736.25 17.47 0.24 -0.63 738.25 17.57 0.51 -0.36 3.55 24.8 1.63 0.88 740.25 17.67 0.77 -0.11 742.25 17.77 1.12 0.23 3.87 25.8 2.43 1.22 744.25 17.87 0.6 -0.29 746.25 17.97 0.63 -0.27 4.13 26.5 2.07 0.94 748.25 18.07 0.44 -0.47 3.48 24.6 1.48 1.05 750.25 18.17 0.47 -0.45 3.97 26.1 1.81 0.83 752.25 18.27 0.3 -0.63 754.25 18.39 0.7 -0.23 3.6 25 1.8 0.99 756.25 18.5 0.8 -0.14 3.38 24.3 1.74 0.85 758.25 18.61 0.75 -0.19 3.64 25.1 1.86 760.25 18.73 0.44 -0.51 762.25 18.84 0.55 -0.41 3.36 24.2 1.45 1.01 764.25 18.96 0.57 -0.4 3.69 25.3 1.69 1.09 766.25 19.07 0.18 -0.82 4.21 26.7 1.56 768.25 19.18 0.19 -0.81 770.25 19.3 0.65 -0.35 4.19 26.7 2.03 1.25 772.25 19.41 0.8 -0.2 3.8 25.6 1.95 1.17 774.25 19.53 0.6 -0.4 3.44 24.5 1.53 0.97 776.25 19.64 0.32 -0.68 778.25 19.76 0.47 -0.53 4.05 26.3 1.77 0.93 780.25 19.87 0.21 -0.79 782.25 19.98 0.41 -0.59 3.71 25.3 1.5 0.98 848.25 23.75