Western Arctic Ocean 8KYr BWT and Sea Ice Reconstructions ----------------------------------------------------------------------- World Data Center for Paleoclimatology, Boulder and NOAA Paleoclimatology Program ----------------------------------------------------------------------- NOTE: Please cite original reference when using these data, plus the data file URL and date accessed. NAME OF DATA SET: Western Arctic Ocean 8KYr BWT and Sea Ice Reconstructions LAST UPDATE: 1/2012 (Original receipt by WDC Paleo) CONTRIBUTORS: Farmer, J.R., T.M. Cronin, A. de Vernal, G.S. Dwyer, L.D. Keigwin, and R.C. Thunell IGBP PAGES/WDCA CONTRIBUTION SERIES NUMBER: 2012-002 WDC PALEO CONTRIBUTION SERIES CITATION: Farmer, J.R., et al. 2012. Western Arctic Ocean 8KYr BWT and Sea Ice Reconstructions. IGBP PAGES/World Data Center for Paleoclimatology Data Contribution Series # 2012-002. NOAA/NCDC Paleoclimatology Program, Boulder CO, USA. ORIGINAL REFERENCE: Farmer, J.R., T.M. Cronin, A. de Vernal, G.S. Dwyer, L.D. Keigwin, and R.C. Thunell. 2011. Western Arctic Ocean temperature variability during the last 8000 years. Geophysical Research Letters, Vol. 38, L24602, doi:10.1029/2011GL049714. ABSTRACT: We reconstructed subsurface (~200-400 m) ocean temperature and sea-ice cover in the Canada Basin, western Arctic Ocean from foraminiferal d18O, ostracode Mg/Ca ratios, and dinocyst assemblages from two sediment core records covering the last 8000 years. Results show mean temperature varied from -1 to 0.5°C and -0.5 to 1.5°C at 203 and 369 m water depths, respectively. Centennial-scale warm periods in subsurface temperature records correspond to reductions in summer sea-ice cover inferred from dinocyst assemblages around 6.5 ka, 3.5 ka, 1.8 ka and during the 15th century Common Era. These changes may reflect centennial changes in the temperature and/or strength of inflowing Atlantic Layer water originating in the eastern Arctic Ocean. By comparison, the 0.5 to 0.7°C warm temperature anomaly identified in oceanographic records from the Atlantic Layer of the Canada Basin exceeded reconstructed Atlantic Layer temperatures for the last 1200 years by about 0.5°C. ADDITIONAL REFERENCES: Darby, D.A, J. Bischof, G. Cutter, A. de Vernal, C. Hillaire-Marcel, G. Dwyer, J. McManus, L. Osterman, L. Polyak, and R. Poore. 2001. New record of pronounced changes in Arctic Ocean circulation and climate. Eos Trans., AGU 82 (49), 603-607. Keigwin, L.D., J.P. Donnelly, M.S. Cook, N.W. Driscoll, and J. Brigham-Grette. 2006. Rapid sea-level rise and Holocene climate in the Chukchi Sea. Geology, 34(10), 861-864, doi:10.1130/G22712.1. GEOGRAPHIC REGION: Canada Basin, western Arctic Ocean PERIOD OF RECORD: 8 KYrBP - present FUNDING SOURCES: US Geological Survey Global Change Program, US National Science Foundation Office of Polar Programs, Fond québécois de la recherché sur la nature et les technologies (FQRNT), Ministere du Développement économique, innovation et exportation (MDEIE) of Quebec. DATA FILE URLS: ftp://ftp.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/farmer2011/farmer2011.txt ftp://ftp.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/farmer2011/farmer2011.xls DESCRIPTION: We reconstructed subsurface ocean temperature and surface sea-ice duration at centennial to submillenial-scale resolution from cores HLY0205-GGC19 and P1-92AR-P1/B3 in the Canada Basin, Arctic Ocean. Oxygen isotopic composition of benthic foraminifers and magnesium to calcium (Mg/Ca) ratios in ostracodes were used as temperature proxies, with sea-ice duration interpreted from dinocyst assemblages. Chronology for both cores was established with radiocarbon dating Data Include: 1. 14C chronology for both cores 2. GGC19 bottom water temperature from d18O of benthic foraminifer Islandiella helenae 3. GGC19 bottom water temperature from d18O of benthic foraminifer Nonion labradoricum 4. GGC19 sea-ice duration (months/year) from dinocyst assemblages 5. P1/B3 ostracode Mg/Ca and BWT, and sea-ice duration Core Locations: HLY0205-GGC19: 72.1555°N, 155.5082°W, 369 m depth. P1-92AR-P1/B3: 73°42.40'N, 162°44.6W, 203 m depth. DATA: 1. 14C Age Information Core Depth(cm) CompositeDepth Material Dated 14C Age deltaR=400 deltaR=506 2-sigma range Source 92AR-B3 0-1 0.5 mixed benthic foraminifer 940 ± 70 170 66-266 Darby et al. (2001) 92AR-B3 12-13 12.5 mollusc fragments 1230 ± 30 450 384-525 Darby et al. (2001) 92AR-B3 25-26 25.5 mollusc fragments 1530 ± 30 690 629-746 Darby et al. (2001) 92AR-B3 41-42 41.5 mollusc fragments 1980 ± 30 1140 1063-1218 Darby et al. (2001) 92AR-P1 24-26 45 mollusc fragments 2170 ± 90 1330 1216-1444 Darby et al. (2001) 92AR-P1 49-51 70 mollusc fragments 3340 ± 50 2710 2464-2890 Darby et al. (2001) 92AR-P1 64-66 85 mixed benthic foraminifer 5120 ± 110 4990 4639-5304 Darby et al. (2001) 92AR-P1 99-100 119.5 mixed benthic foraminifer 6240 ± 70 6260 6171-6367 Darby et al. (2001) 92AR-P1 105 125 Bathyarca sp. 6590 ± 70 6630 6510-6736 Darby et al. (2001) 92AR-P1 134-136 155 mixed benthic foraminifer 7030 ± 110 7140 6996-7279 Darby et al. (2001) GGC-19 56 mixed benthic foraminifer 2040 ± 35 1090 975-1182 Keigwin et al. (2006) GGC-19 166 mollusc fragments 3650 ± 40 2930 2804-3061 this study GGC-19 220.5 mixed benthic foraminifer 4270 ± 40 3700 3582-3822 Keigwin et al. (2006) GGC-19 326 Portlandia arctica 5040 ± 35 4740 4616-4829 this study GGC-19 336 mollusc fragments 5320 ± 35 5110 4970-5250 this study GGC-19 339 Nonion labradoricum 5290 ± 50 5060 4883-5243 Keigwin et al. (2006) GGC-19 361 Portlandia arctica 5570 ± 50 5420 5303-5550 this study GGC-19 400 mixed benthic foraminifer 5840 ± 80 5700 5561-5890 Keigwin et al. (2006) GGC-19 411 Neptunea sp. (gastropod) 6260 ± 40 6180 6050-6275 this study 2. Core GGC19 bottom water temperature from d18O (per mil VPDB) of benthic foraminifer Islandiella helenae Depth Age(yrBP) d18O-Isl. BWT-Islandiella (deg C) 3 52 4.211 0.23 8 137 4.241 0.12 12 206 4.228 0.17 24 412 4.332 -0.2 26 447 4.236 0.14 28 481 4.282 -0.02 31 533 4.179 0.34 34 584 4.274 0.01 36 618 4.257 0.07 41 704 4.36 -0.3 46 790 4.321 -0.16 51 876 4.362 -0.3 58 996 4.258 0.06 61 1048 4.304 -0.1 66 1134 4.289 -0.05 71 1220 4.365 -0.31 76 1306 4.318 -0.15 81 1392 4.239 0.13 86 1477 4.372 -0.34 91 1563 3.938 1.2 98 1684 4.11 0.59 101 1735 4.263 0.05 104 1787 4.228 0.17 106 1821 4.148 0.45 108.5 1864 4.263 0.05 111 1907 4.098 0.63 114 1959 4.213 0.22 116 1993 4.24 0.13 120 2062 4.021 0.91 123 2113 3.982 1.04 125 2148 4.293 -0.06 130 2233 4.252 0.08 133 2285 4.299 -0.08 135 2319 4.189 0.31 137.5 2362 4.211 0.23 140 2405 4.269 0.03 143 2457 4.246 0.1 145 2491 4.277 0 155 2663 4.048 0.81 165 2835 4.189 0.31 177.5 3049 4.159 0.41 180 3092 3.877 1.42 185 3178 4.186 0.32 190 3264 4.31 -0.12 195 3350 3.914 1.29 200 3436 4.19 0.31 205 3522 4.075 0.71 210 3608 3.77 1.81 215 3694 4.233 0.15 220 3700 4.21 0.23 225 3738 4.226 0.18 230 3794 4.04 0.84 235 3850 4.382 -0.37 240 3907 4.184 0.33 245 3963 4.248 0.1 255 4075 4.314 -0.14 260 4131 4.136 0.49 265 4188 3.994 1 270 4244 4.23 0.16 275 4300 4.236 0.14 285 4412 4.157 0.42 290 4469 4.285 -0.03 295 4525 4.154 0.43 300 4581 4.101 0.62 305 4637 4.25 0.09 325 4862 4.187 0.32 335 4974 4.257 0.07 345 5180 4.191 0.3 360 5373 4.042 0.83 365 5437 4.191 0.3 370 5502 4.233 0.15 375 5566 4.171 0.37 380 5630 4.309 -0.12 385 5695 4.22 0.2 390 5759 4.412 -0.48 400 5888 4.076 0.71 405 5952 4.211 0.23 410 6016 4.262 0.05 415 6081 4.292 -0.06 420 6145 4.15 0.45 425 6210 4.118 0.56 430 6274 4.232 0.15 435 6338 4.244 0.11 440 6403 4.182 0.33 445 6467 4.021 0.91 450 6531 4.15 0.44 455 6596 4.068 0.74 460 6660 4.081 0.69 3. Core GGC19 bottom water temperature from d18O (per mil VPDB) of benthic foraminifer Nonion labradoricum Depth Age d18O-Nonion BWT-Nonion (deg C) 16 275 4.195 0.29 24 412 4.225 0.18 26 447 4.211 0.23 28 481 4.219 0.2 31 533 4.124 0.54 34 584 4.265 0.04 36 618 4.209 0.24 41 704 4.322 -0.16 46 790 4.261 0.05 61 1048 4.373 -0.34 66 1134 4.235 0.14 76 1306 4.305 -0.1 81 1392 4.265 0.04 86 1477 4.433 -0.55 91 1563 4.195 0.29 106 1821 4.023 0.9 108.5 1864 4.229 0.17 111 1907 4.309 -0.12 118.5 2036 4.268 0.03 121 2079 4.267 0.03 124 2130 4.294 -0.07 126 2165 4.253 0.08 128.5 2208 4.423 -0.52 137.5 2362 4.351 -0.26 140 2405 4.25 0.09 143 2457 3.853 1.51 145 2491 4.196 0.28 150 2577 4.329 -0.19 153 2629 4.182 0.33 155 2663 4.162 0.4 177.5 3049 4.245 0.11 180 3092 4.227 0.17 190 3264 4.263 0.05 195 3350 4.241 0.12 200 3436 4.158 0.42 205 3522 4.289 -0.05 210 3608 3.894 1.36 215 3694 4.163 0.4 225 3738 4.234 0.15 230 3794 3.775 1.79 235 3850 4.32 -0.16 240 3907 4.148 0.45 245 3963 4.294 -0.06 255 4075 4.219 0.2 265 4188 4.257 0.07 275 4300 4.117 0.56 280 4356 3.977 1.06 285 4412 4.244 0.11 290 4469 4.287 -0.04 295 4525 4.189 0.31 305 4637 4.44 -0.58 335 4974 4.333 -0.2 345 5180 4.455 -0.63 355 5309 4.31 -0.12 357 5334 4.252 0.08 370 5502 4.371 -0.33 380 5630 4.339 -0.22 390 5759 4.411 -0.48 395 5823 4.284 -0.03 400 5888 4.305 -0.1 405 5952 4.227 0.17 410 6016 4.454 -0.63 415 6081 4.602 -1.14 420 6145 4.3 -0.08 425 6210 4.45 -0.61 430 6274 4.355 -0.28 435 6338 4.431 -0.55 440 6403 4.343 -0.24 445 6467 4.424 -0.52 450 6531 4.346 -0.25 455 6596 4.309 -0.12 460 6660 4.449 -0.61 4. Core GGC19 sea-ice duration (months/year) from dinocyst assemblages Depth Age(yrBP) Sea Ice (months/year) 4 69 7.1 14 241 9.4 24 412 9.1 34 584 7.6 44 756 8.8 54 928 9.1 64 1100 8.4 74 1271 8.2 84 1443 9.1 94 1615 8.9 104 1787 9.4 114 1959 6.3 124 2130 8.6 134 2302 6.6 144 2474 9.1 154 2646 8.8 164 2818 8.9 174 2989 7.7 184 3161 8.4 194 3333 8.1 204 3505 3.3 213 3651 3.7 224 3727 4 234 3839 5 244 3952 9.4 254 4064 8 264 4176 9.1 274 4289 8.1 284 4401 6.2 294 4514 8.5 304 4626 8.8 314 4738 9.3 324 4851 8.4 334 4963 9.1 344 5167 9.1 354 5296 9.1 364 5424 5.4 374 5553 9.2 384 5682 8.1 394 5811 8.3 404 5939 6.3 414 6068 4.3 424 6197 4.3 434 6325 9.1 444 6454 8.5 454 6583 7.3 5. Core P1/B3 ostracode Mg/Ca and BWT, and sea-ice duration Depth Age Mg/Ca BWT(deg C) Seaice (months/year) 1 144 7.97 -0.54 9.6 2 169 7.7 3 195 7.32 -0.78 5.4 4 220 7.3 5 246 7.82 -0.6 6.8 6 272 7.33 -0.78 6.8 7 297 7.61 -0.68 7.2 8 323 7.64 -0.67 5 9 348 7.41 -0.75 8.3 10 374 7.81 -0.6 7.1 11 400 7.4 12 425 7.66 -0.66 8.5 13 451 6.38 -1.14 8.4 14 476 7.9 -0.57 8 15 502 9.37 -0.01 6.1 16 528 8.17 -0.46 8.2 17 553 7.94 -0.55 6.6 18 579 9.29 -0.05 7.6 19 604 8 20 630 6.99 -0.91 8.1 20 630 21 656 7.7 21 656 7.67 -0.66 22 681 7.2 23 707 7.47 -0.73 5.7 24 732 7.6 -0.68 9.6 25 758 8 25 758 6.92 -0.94 26 784 6.6 27 809 6.84 -0.96 7.7 28 835 8.49 -0.35 6.4 29 860 8.99 -0.16 30 886 7.2 30 886 7.61 -0.68 31 912 8.26 -0.43 32 937 7.87 -0.58 9.4 34 988 7.68 -0.65 8.2 35 1014 6.76 -0.93 7.3 36 1040 6.5 39 1116 7.74 -0.63 7.2 40 1142 7.1 -0.68 7.7 41 1168 8.42 -0.37 7.3 42 1193 9.5 0.03 43 1219 7.42 -0.75 47 1470 7.27 -0.8 50 1770 7.57 -0.69 8.3 51 1870 8.9 52.5 2020 6.8 -0.98 55 2270 7.4 56 2370 6.5 60 2770 7.87 -0.58 7.4 61 2870 3.5 65 3270 7.1 66 3370 4.6 67.5 3520 6.92 -0.93 70 3770 10.15 0.28 5.3 75 4270 76 4370 7.6 80 4770 6.9 81 4870 7.5 85 5270 9.3 86 5303 6.7 87.5 5353 7.17 -0.84 90 5436 7.45 -0.73 7.9 91 5470 7.5 95 5603 8.09 -0.5 7.2 96 5636 6.8 100 5769 8.4 101 5803 4.2 102.5 5852 7.14 -0.85 105 5936 8.21 -0.45 2.7 106 5969 9.5 107.5 6019 7.33 -0.78 110 6102 8.07 -0.5 7.6 111 6136 7.7 115 6269 9.77 0.13 7.9 116 6302 7.4 117.5 6352 7.71 -0.64 120 6435 7.33 -0.78 8.9 121 6469 7.5 125 6602 7.57 -0.69 7.9 126 6635 4.6 127.5 6685 10.53 0.42 130 6768 6.99 -0.91 7.2 131 6802 7.5 132.5 6851 8.39 -0.38 135 6935 8.5 140 7101 7.99 -0.53 7.9 141 7135 5.4 142.5 7184 10.15 0.28 145 7268 8.3 146 7301 7.9 147.5 7351 6.86 -0.96 150 7434 7.98 -0.54 6.3 151 7468 6 152.5 7517 8.21 -0.45 155 7601 8.7 156 7634 8.1 157.5 7684 7.54 -0.7 160 7767 7.1 162 7834 6.4 -1.13 9.8 165 7934 7.9 166 7967 8.2 170 8100 7.2