# Guaymas Basin 9-12kYrBP Leaf Wax Isotopes and Precipitation Reconstructions #----------------------------------------------------------------------- # World Data Service for Paleoclimatology, Boulder # and # NOAA Paleoclimatology Program # National Centers for Environmental Information (NCEI) #----------------------------------------------------------------------- # Template Version 3.0 # Encoding: UTF-8 # NOTE: Please cite Publication, and Online_Resource and date accessed when using these data. # If there is no publication information, please cite Investigators, Title, and Online_Resource and date accessed. # # Online_Resource: https://www.ncdc.noaa.gov/paleo/study/24890 # Description: # Online_Resource: https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/bhattacharya2018/bhattacharya2018md022517.txt # Description: # # Original_Source_URL: # Description: # # Description/Documentation lines begin with # # Data lines have no # # # Archive: Paleoceanography # # Dataset_DOI: # # Parameter_Keywords: biomarkers, carbon isotopes #-------------------- # Contribution_Date # Date: 2018-09-03 #-------------------- # File_Last_Modified_Date # Date: 2018-09-03 #-------------------- # Title # Study_Name: Guaymas Basin 9-12kYrBP Leaf Wax Isotopes and Precipitation Reconstructions #-------------------- # Investigators # Investigators: Bhattacharya, T.; Tierney, J.E.; Addison, J.A.; Murray, J.W. #-------------------- # Description_Notes_and_Keywords # Description: Stable isotope (dD and d13C) data on leaf waxes, plus summer (July-September) monsoon precipitation reconstructions from 4 sediment cores collected in the Guaymas Basin, Gulf of California, for the interval 9-12 kYrBP. #-------------------- # Publication # Authors: Tripti Bhattacharya, Jessica E. Tierney, Jason A. Addison, James W. Murray # Published_Date_or_Year: 2018-09-03 # Published_Title: Ice sheet modulation of deglacial North American Monsoon intensification # Journal_Name: Nature Geoscience # Volume: # Edition: # Issue: # Pages: # Report_Number: # DOI: 10.1038/s41561-018-0220-7 # Online_Resource: https://www.nature.com/articles/s41561-018-0220-7 # Full_Citation: # Abstract: The North American monsoon, the dominant source of rainfall for much of the arid US Southwest, remains one of the least understood monsoon systems. The late Pleistocene evolution of this monsoon is poorly constrained, largely because glacial changes in winter rainfall obscure summer monsoon signatures in many regional proxy records. Here, we develop deglacial records of monsoon strength from isotopic analyses of leaf wax biomarkers in marine sediment cores. Reconstructions indicate a regional decrease in monsoon rainfall during the Last Glacial Maximum, and that the deglacial trajectory of the North American monsoon closely tracks changes in North American ice cover. In climate model simulations, North American ice cover shifts the westerlies southwards, favouring the mixing of cold, dry air into the US Southwest. This process, known as ventilation, weakens the monsoon by diluting the energy fluxes required for convection. As the ice sheet retreats northwards, the monsoon strengthens, and local ocean conditions may play a larger role in regulating its intensity. We conclude that on glacial-interglacial timescales, ice-sheet-induced reorganizations of atmospheric circulation have a dominant influence on the North American monsoon. #------------------ # Funding_Agency # Funding_Agency_Name: US National Science Foundation # Grant: OCE-1651034 #------------------ # Funding_Agency_Name: David and Lucile Packard Foundation # Grant: #------------------ # Site_Information # Site_Name: MD02-2517 # Location: Ocean>Pacific Ocean>Eastern Pacific Ocean # Country: Mexico # Northernmost_Latitude: 27.48 # Southernmost_Latitude: 27.48 # Easternmost_Longitude: -112.07 # Westernmost_Longitude: -112.07 # Elevation: -881 m #------------------ # Data_Collection # Collection_Name: Bhattacharya2018MD022517 # Earliest_Year: 5795 # Most_Recent_Year: 1571 # Time_Unit: Cal. Years BP # Core_Length: 4 # Notes: #------------------ # Chronology_Information # depth_top depth_bottom Material_dated 14C_raw 14C_raw_err benthic/planktic_correct datemeth calib_curve delta_R delta_R_err cal.age cal.error # 49 50 Mixed benthic forams 2230 40 1430 14C AMS Marine13 340 116 690 104 # 96 97 Mixed benthic forams 3275 40 2475 14C AMS Marine13 340 116 1706 147 # 198 199 Mixed planktic forams 4325 40 4325 14C AMS Marine13 340 116 4009 170 # 256 257 Mixed planktic forams 4840 35 4840 14C AMS Marine13 340 116 4691 159 # 280 281 Mixed planktic forams 4925 30 4925 14C AMS Marine13 340 116 4806 181 # 311 312 Mixed planktic forams 5100 35 5100 14C AMS Marine13 340 116 5041 169 # 336 337 Mixed planktic forams 5370 30 5370 14C AMS Marine13 340 116 5328 148 # 431 432 Mixed planktic forams 7015 30 7015 14C AMS Marine13 340 116 7169 127 #---------------- # Variables # # Data variables follow are preceded by "##" in columns one and two. # Data line variables format: one per line, shortname-tab-variable components (what, material, error, units, seasonality, data type,detail, method, C or N for Character or Numeric data, additional information) # ## depth_cm depth, , , cm, , , , ,N, ## age_calBP age, , , calendar years before present, , , , ,N, ## dDwax delta D, C-30 fatty acid,,per mil VSMOW,,Paleoceanography,,compound-specific isotope ratio mass spectrometry,N, ## dDwax-iv delta D, C-30 fatty acid,,per mil VSMOW,,Paleoceanography,corrected,compound-specific isotope ratio mass spectrometry,N, corrected for ice volume ## d13Cwax delta 13C, C-30 fatty acid,,per mil VSMOW,,Paleoceanography,,compound-specific isotope ratio mass spectrometry,N, ## percentJAS precipitation,,,percent,July-September, Climate Reconstruction,,Bayesian inference,N, Mean percent July-September rainfall ## JASerror precipitation error,,,percent,July-September, Climate Reconstruction,,Bayesian inference,N, error for Mean percent July-September rainfall # #---------------- # Data: # Data lines follow (have no #) # Data line format - tab-delimited text, variable short name as header # Missing_Values: (Value used to flag missing data in the table below) # depth_cm age_calBP dDwax dDwax-iv d13Cwax percentJAS JASerror 97.5 1571.8 -147.22 -147.13 -26.389 80.315 8.0457 106.5 1718.2 -152.46 -152.34 -26.194 71.036 7.9974 115.5 1866.5 -148.4 -148.24 -26.848 76.545 8.0679 125.5 2034.5 -150.99 -150.8 -26.428 73.32 7.833 135.5 2199.8 -147.7 -147.59 -25.874 81.09 8.1612 145 2358.3 -150.22 -150.17 -26.974 72.589 8.084 155.5 2529.9 -150.13 -150.16 -26.385 74.453 7.8565 165.5 2695.2 -145.88 -145.98 -26.109 83.441 8.0716 176.5 2875.5 -150.47 -150.65 -26.487 73.097 8.033 186.5 3039.2 -147.68 -147.91 -26.417 78.714 8.1624 195.5 3185.9 -146.12 -146.36 -26.33 81.992 7.9607 205 3325.7 -147.56 -147.81 -26.773 77.775 8.0001 215.5 3462.8 -148.17 -148.42 -26.083 78.864 7.8452 222.5 3555.7 -149.4 -149.65 -26.193 75.895 8.2666 232.5 3686 -148.16 -148.42 -25.882 79.428 7.9743 240.5 3789.8 -151.73 -151.99 -26.26 71.664 8.0631 250.5 3920 -151.29 -151.55 -26.067 72.539 7.9358 262.6 4070.9 -150.39 -150.65 -26.038 74.409 7.9478 270.5 4160.9 -149.36 -149.61 -25.988 77.133 7.9224 281.5 4286.9 -151.51 -151.73 -25.928 73.331 7.789 289.5 4379.5 -148.15 -148.36 -27.742 73.323 8.0292 302.5 4527.2 -150.14 -150.32 -26.19 74.821 7.8203 312.5 4641.6 -151.15 -151.32 -25.969 74.005 8.036 320.5 4738.5 -152.14 -152.3 -26.393 70.475 7.9242 330.5 4861.4 -148.65 -148.78 -26.466 76.992 7.857 339.5 4973.8 -149.9 -150.02 -26.231 75.428 8.0135 351.5 5133.2 -152.48 -152.63 -26.042 71.174 7.9958 362.5 5278.3 -152.17 -152.35 -26.735 69.514 8.0257 370.5 5384.8 -151.39 -151.6 -26.075 72.701 8.176 381.5 5529.6 -157.29 -157.54 -25.87 62.624 8.1369 390.5 5648.9 -151.03 -151.31 -25.635 74.077 7.9321 401.5 5795.4 -150.69 -151.02 -26.119 73.84 7.8355