Late-glacial to late-Holocene shifts in global precipitation δ 18 O

• Main Authors: Jasechko, S., Lechler, A., Pausata, F. S. R., Fawcett, P. J., Gleeson, T., Cendón, D. I., Galewsky, J., Legrande, A. N., Risi, C., Sharp, Z. D., Welker, J. M., Werner, M., Yoshimura, K.
• Other Authors: Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2015
• Subjects: Earth Science; [SDU]Sciences of the Universe [physics]; ice core
• Online Access: https://hal.science/hal-04114714; https://doi.org/10.5194/cp-11-1375-201510.5194/cpd-11-831-2015

International audience 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 δ 18 O. 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 δ 18 O changes from the late-glacial to the late-Holocene range from -7.1 ‰ (δ 18 O late-Holocene > δ 18 O late-glacial ) to +1.7 ‰ (δ 18 O late-glacial > δ 18 O late-Holocene ), with the majority (77 %) of records having lower late-glacial δ 18 O than late-Holocene δ 18 O values. High-magnitude, negative precipitation δ 18 O shifts are common at high latitudes, high altitudes and continental interiors (δ 18 O late-Holocene > δ 18 O late-glacial by more than 3 ‰). Conversely, low-magnitude, positive precipitation δ 18 O shifts are concentrated along tropical and subtropical coasts (δ 18 O late-glacial > δ 18 O late-Holocene by less than 2 ‰). Broad, global patterns of late-glacial to late-Holocene precipitation δ 18 O 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 δ 18 O shifts, we compiled simulated precipitation δ 18 O 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 ...