Late-glacial to late-Holocene shifts in global precipitation δ18O - Sorbonne Université Access content directly
Journal Articles Climate of the Past Year : 2015

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

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 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 con-vective rainout, seawater δ 18 O and glacial topography pa-rameterizations impact simulated precipitation δ 18 O. Future research on paleo-precipitation δ 18 O records can use the global maps of measured and simulated late-glacial precipitation isotope compositions to target and prioritize field sites.
Fichier principal
Vignette du fichier
cp-11-1375-2015.pdf (2.77 Mo) Télécharger le fichier
Origin Publication funded by an institution
Loading...

Dates and versions

hal-01259458 , version 1 (20-01-2016)

Licence

Identifiers

Cite

S. Jasechko, A Lechler, F.S.R. Pausata, P.J. Fawcett, T. Gleeson, et al.. Late-glacial to late-Holocene shifts in global precipitation δ18O. Climate of the Past, 2015, 11 (10), pp.1375-1393. ⟨10.5194/cp-11-1375-2015⟩. ⟨hal-01259458⟩
834 View
270 Download

Altmetric

Share

Gmail Mastodon Facebook X LinkedIn More