# 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/bhattacharya2018jpc56.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: JPC-56 # Location: Ocean>Pacific Ocean>Eastern Pacific Ocean # Country: Mexico # Northernmost_Latitude: 27.47 # Southernmost_Latitude: 27.47 # Easternmost_Longitude: -112.1 # Westernmost_Longitude: -112.1 # Elevation: -881 m #------------------ # Data_Collection # Collection_Name: Bhattacharya2018JPC56 # Earliest_Year: 9798 # Most_Recent_Year: 12900 # Time_Unit: Cal. Years BP # Core_Length: 10.9 # Notes: #------------------ # Chronology_Information # Chronology: See Keigwin, L.D., 2002. Late Pleistocene–Holocene paleoceanography and ventilation of the Gulf of California. # J. Oceanogr. 58, 421– 432, doi: 10.1023/A:1015830313175 # #---------------- # 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 512 9798.6 -147.94 -148.94 -26.429 77.587 7.8528 537 9899.6 -150.36 -151.41 -26.313 73.239 7.8871 593 10134 -147.32 -148.47 -26.717 76.986 8.1359 609 10197 -149.57 -150.73 -26.118 74.624 8.0159 658 10395 -148.86 -150.08 -25.753 77.187 8.0041 701 10593 -150.65 -151.93 -26.282 72.452 7.8048 741 10789 -156.35 -157.68 -26.004 62.068 8.0316 762 10889 -152.29 -153.66 -26.508 68.636 7.8856 823 11189 -154.04 -155.67 -26.63 63.91 8.0646 876 11461 -148.75 -150.72 -26.35 74.31 8.0889 899 11581 -148.29 -150.41 -27.246 71.68 8.2013 944 11856 -149.3 -151.75 -25.874 73.493 7.928 964 11987 -146.47 -149.08 -25.742 78.84 7.8467 1011 12323 -155.14 -157.92 -26.206 60.872 8.0186 1023 12417 -154.98 -157.8 -26.159 61.616 8.0847 1048 12606 -155.47 -158.39 -26.011 60.91 8.0551 1063 12717 -156.56 -159.54 -26.302 58.167 8.0865 1088 12911 -154.71 -157.8 -25.806 62.295 7.9379