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Late-glacial to late-Holocene shifts in global precipitation δ18O

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dc.contributor.author Jasechko, S.
dc.contributor.author Lechler, A.
dc.contributor.author Pausata, F. S. R.
dc.contributor.author Fawcett, P. J.
dc.contributor.author Gleeson, Tom
dc.contributor.author Cendón, D. I.
dc.contributor.author Galewsky, J.
dc.contributor.author LeGrande, A. N.
dc.contributor.author Risi, C.
dc.contributor.author Sharp, Z. D.
dc.contributor.author Welker, J. M.
dc.contributor.author Werner, M.
dc.contributor.author Yoshimura, K.
dc.date.accessioned 2017-07-18T15:18:29Z
dc.date.available 2017-07-18T15:18:29Z
dc.date.copyright 2015 en_US
dc.date.issued 2015
dc.identifier.citation Jasechko S. et al. (2015). Late-glacial to late-Holocene shifts in global precipitation δ18O. Climate of the Past 11, 1375-1393. doi: 10.5194/cp-11-1375-2015 en_US
dc.identifier.uri http://dx.doi.org/10.5194/cp-11-1375-2015
dc.identifier.uri https://dspace.library.uvic.ca//handle/1828/8346
dc.description.abstract Reconstructions of Quaternary climate are often based on the isotopic content of paleo-precipitation preserved in proxy records. While many paleo-precipitation isotope records are available, few studies have synthesized these dispersed records to explore spatial patterns of late-glacial precipitation δ18O. Here we present a synthesis of 86 globally distributed groundwater (n = 59), cave calcite (n = 15) and ice core (n = 12) isotope records spanning the late-glacial (defined as ~ 50 000 to ~ 20 000 years ago) to the late-Holocene (within the past ~ 5000 years). We show that precipitation δ18O changes from the late-glacial to the late-Holocene range from −7.1 ‰ (δ18Olate-Holocene > δ18Olate-glacial) to +1.7 ‰ (δ18Olate-glacial > δ18Olate-Holocene), with the majority (77 %) of records having lower late-glacial δ18O than late-Holocene δ18O values. High-magnitude, negative precipitation δ18O shifts are common at high latitudes, high altitudes and continental interiors (δ18Olate-Holocene > δ18Olate-glacial by more than 3 ‰). Conversely, low-magnitude, positive precipitation δ18O shifts are concentrated along tropical and subtropical coasts (δ18Olate-glacial > δ18Olate-Holocene by less than 2 ‰). Broad, global patterns of late-glacial to late-Holocene precipitation δ18O shifts suggest that stronger-than-modern isotopic distillation of air masses prevailed during the late-glacial, likely impacted by larger global temperature differences between the tropics and the poles. Further, to test how well general circulation models reproduce global precipitation δ18O shifts, we compiled simulated precipitation δ18O shifts from five isotope-enabled general circulation models simulated under recent and last glacial maximum climate states. Climate simulations generally show better inter-model and model-measurement agreement in temperate regions than in the tropics, highlighting a need for further research to better understand how inter-model spread in convective rainout, seawater δ18O and glacial topography parameterizations impact simulated precipitation δ18O. Future research on paleo-precipitation δ18O records can use the global maps of measured and simulated late-glacial precipitation isotope compositions to target and prioritize field sites. en_US
dc.description.sponsorship We acknowledge support from the University of Calgary’s Open Access Author’s Fund, an NSERC Discovery Grant held by S. Jasechko, the UNESCO IGCP-618 project (Paleoclimate information obtained from past-recharged groundwater), the G@GPS network, and the Caswell Silver Foundation. en_US
dc.language.iso en en_US
dc.publisher Climate of the Past en_US
dc.rights Attribution 2.5 Canada *
dc.rights.uri http://creativecommons.org/licenses/by/2.5/ca/ *
dc.title Late-glacial to late-Holocene shifts in global precipitation δ18O en_US
dc.type Article en_US
dc.description.scholarlevel Faculty en_US
dc.description.reviewstatus Reviewed en_US


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