# Western Tropical North Atlantic Foraminifera-based Nd Isotope Data Since the Last Glacial Maximum #----------------------------------------------------------------------- # World Data Center for Paleoclimatology, Boulder # and # NOAA Paleoclimatology Program #----------------------------------------------------------------------- # 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: http://www.hurricane.ncdc.noaa.gov/pls/paleox/f?p=519:1:::::P1_STUDY_ID:16156 # # Original_Source_URL: ftp://ftp.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/huang2014/huang2014-46cdh.txt # # Archive: Paleoceanography #--------------------------------------- # Contribution_Date # Date: 2014-03-17 #--------------------------------------- # Title # Study_Name: Western Tropical North Atlantic Foraminifera-based Nd Isotope Data Since the Last Glacial Maximum #--------------------------------------- # Investigators # Investigators: Huang, K.-F.; Oppo, D.W.; Curry, W.B. #--------------------------------------- # Description and Notes # Description: Keywords from journal: Nd isotopes; Antarctic intermediate water; Atlantic meridional overturning circulation; deglacial variability; North Atlantic cold events #--------------------------------------- # Publication # Authors: Huang, K.-F., D.W. Oppo, and W.B. Curry # Published_Date_or_Year: 2014 # Published_Title: Decreased influence of Antarctic intermediate water in the tropical Atlantic during North Atlantic cold events # Journal_Name: Earth and Planetary Science Letters # Volume: 389 # Issue: # Pages: 200-208 # Report Number: # DOI: 10.1016/j.epsl.2013.12.037 # Abstract: Antarctic Intermediate Water (AAIW) is a key player in the global ocean circulation, contributing to the upper limb of the Atlantic Meridional Overturning Circulation (AMOC), and influencing interhemispheric heat exchange and the distribution of salinity, nutrients and carbon. However, the deglacial history of AAIW flow into the North Atlantic is controversial. Here we present a multicore-top neodymium isotope calibration, which confirms the ability of unclean foraminifera to faithfully record bottom water neodymium isotopic composition (eNd) values in their authigenic coatings. We then present the first foraminifera-based reconstruction of eNd from three sediment cores retrieved from within modern AAIW, in the western tropical North Atlantic. Our records reveal similar glacial and interglacial contributions of AAIW, and a pronounced decrease in the AAIW fraction during North Atlantic deglacial cold episodes, Heinrich Stadial 1 (HS1) and Younger Dryas (YD). Our results suggest two separate phases of reduced fraction of AAIW in the tropical Atlantic during HS1, with a greater reduction during early HS1. If a reduction in AAIW fraction also reflects reduced AMOC strength, these finding may explain why, in many regions, there are two phases of hydrologic change within HS1, and why atmospheric CO2 rose more rapidly during early than late HS1. Our result suggesting less flow of AAIW into the Atlantic during North Atlantic cold events contrasts with evidence from the Pacific, where intermediate-depth eNd records may indicate increased flow of AAIW into the Pacific during the these same events. Antiphased eNd behavior between intermediate depths of the North Atlantic and Pacific implies that the flow of AAIW into Atlantic and Pacific seesawed during the last deglaciation. #--------------------------------------- # Funding_Agency # Funding_Agency_Name: National Science Foundation # Grant: #--------------------------------------- # Funding_Agency # Funding_Agency_Name: Lawrence J. Pratt and Melinda M. Hall Endowed Fund for WHOI Interdisciplinary Research Award # Grant: #--------------------------------------- # Funding_Agency # Funding_Agency_Name: Taiwan National Science Council # Grant: #--------------------------------------- # Site Information # Site_Name: KNR197-3-46CDH # Northernmost_Latitude: 7.836 # Southernmost_Latitude: 7.836 # Easternmost_Longitude: -53.663333 # Westernmost_Longitude: -53.663333 # Elevation: -947 #--------------------------------------- # Data_Collection # Collection_Name: KNR197-3-46CDH eNd Huang14 # First_Year: 22600 # Last_Year: 3760 # Time_Unit: cal yr BP # Core_Length: # Notes: #--------------------------------------- # Chronology: # # Labcode sample identification used by 14C laboratory # depth_top Depth top of sample interval (cm) # depth_bottom Depth bottom of sample interval (cm) # mat.dated Material Dated # 14C.raw conventional radiocarbon age, years before 1950AD # 14C.raw_err radiocarbon age, standard error # datemeth Dating method # reservoir Reservoir correction # delta-R Deviation from global mean reservoir correction # calib.14C Calibrated age # calib.14C_2sig_lo Calibrated age, 2-sigma lower confidence bound # calib.14C_2sig_up Calibrated age, 2-sigma upper confidence bound # calib_method Calibration method # rejected Rejected sample (yes/no) # # KNR197-3-46CDH # Labcode depth_top depth_bottom mat.dated 14C.raw 14C.raw_err datemeth reservoir delta-R cal_BP cal_BP_2sig_lo cal_BP_2sig_up calib_method # OS-87794 0 1 G. ruber and G. sacc 3370 30 14C AMS Marine09 0 3246 3145 3336 Calib 6.0 # OS-98186 0 1 mixed planktonics 3960 20 14C AMS Marine09 0 3950 3867 4054 Calib 6.0 # OS-91338 88 89 G. ruber 4580 35 14C AMS Marine09 0 4803 4672 4877 Calib 6.0 # OS-87802 140 141 G. ruber 7680 50 14C AMS Marine09 0 8140 8011 8277 Calib 6.0 # OS-98192 166 167 mixed planktonics 9260 40 14C AMS Marine09 0 10107 9930 10194 Calib 6.0 # OS-94488 166 167 G. sacculifer 6870 45 14C AMS Marine09 0 7703 7284 7472 Calib 6.0 # OS-91336 200 201 G. ruber 7710 40 14C AMS Marine09 0 8180 8050 8294 Calib 6.0 # OS-98193 200 201 mixed planktonics 8800 30 14C AMS Marine09 0 9471 9415 9523 Calib 6.0 # OS-91303 200 201 Uvigerina sp. 11100 45 14C AMS Marine09 0 12619 12549 12713 Calib 6.0 # OS-94483 224 225 Mixed P 11350 55 14C AMS Marine09 0 13229 12975 12643 Calib 6.0 # OS-87799 232 233 G. ruber/G.sac 12600 60 14C AMS Marine09 0 14047 13817 14244 Calib 6.0 # OS-94357 270 271 G. sacculifer 13700 45 14C AMS Marine09 0 16836 16778 15842 Calib 6.0 # OS-91334 292 293 G. ruber 14750 60 14C AMS Marine09 0 17443 17125 17805 Calib 6.0 # OS-87789 324 325 G. ruber 16250 70 14C AMS Marine09 0 19062 18803 19355 Calib 6.0 # OS-91327 368 369 G. ruber 19400 85 14C AMS Marine09 0 22604 22305 23002 Calib 6.0 # OS-87803 404 405 G. ruber 21400 110 14C AMS Marine09 0 25038 24587 25494 Calib 6.0 # #--------------------------------------- # Variables # Data variables follow (have two #) # Data line variables format: Variables list, one per line, shortname-tab-longname-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_calyrBP age,,,cal yr BP,,,,,N ## eNd epsilon Nd,unclean planktonic foraminifera,,epsilon ,,Paleoceanography,reference period: 0-23 kyr BP,analytical technique: Multi-collector ICP-MS,N ## eNd_err epsilon Nd,unclean planktonic foraminifera,two standard deviation,,epsilon ,,Paleoceanography,reference period: 0-23 kyr BP,analytical technique: Multi-collector ICP-MS,N # Data: # Missing Value: depth_cm age_calkaBP eNd eNd_err notes 0.25 0 -10.5 0.3 28MC (0-0.5) 12.5 3.8 -10.0 0.4 148.5 8.7 -10.1 0.3 172.5 10.4 -10.2 0.3 192.5 11.5 -10.0 0.3 194.5 11.6 -10.3 0.3 196.5 11.7 -10.1 0.3 202.5 12.0 -11.2 0.3 204.5 12.2 -11.3 0.3 206.5 12.3 -11.1 0.3 210.5 12.5 -10.4 0.3 220.5 13.0 -10.3 0.3 234.5 14.2 -10.1 0.4 240.5 14.6 -10.8 0.3 256.5 15.8 -11.1 0.3 264.5 16.4 -10.3 0.3 268.5 16.7 -12.0 0.4 276.5 17.0 -12.2 0.3 280.5 17.1 -12.3 0.3 288.5 17.3 -11.7 0.3 292.5 17.4 -11.9 0.3 308.5 18.3 -10.0 0.3 320.5 18.9 -10.5 0.3 336.5 20.0 -9.4 0.4 344.5 20.7 -10.0 0.3 356.5 21.6 -9.6 0.5 368.5 22.6 -9.4 0.4