Abstract
Oxygen and hydrogen isotope ratios in polar precipitation are widely used as proxies for local temperature. Used in combination, oxygen and hydrogen isotope ratios also provide information on sea surface temperature at the oceanic moisture source locations where polar precipitation originates. Temperature reconstructions obtained from ice core records generally rely on linear approximations of the relationships among local temperature, source temperature and water-isotope values. However, there are important nonlinearities that significantly affect such reconstructions, particularly for source-region temperatures. Here, we describe a temperature reconstruction method that accounts for these nonlinearities. We provide new reconstructions of absolute surface temperature, condensation temperature, and source-region evaporation temperature for all long Antarctic ice-core records for which the necessary data are available. We also provide thorough uncertainty estimates on all temperature histories. Our reconstructions constrain the pattern and magnitude of polar amplification in the past and reveal asymmetries in the temperature histories of East and West Antarctica.
Highlights
Stable-isotope ratios of water have been the foundational proxy of polar paleoclimate research for more than a half-century (Langway, 1958; Gonfiantini, 1959; Dansgaard, 1964)
We describe the construction of the Simple Water Isotope Model (SWIM) in detail in the Appendix
Nonlinear temperature reconstruction technique for eight different ice core sites, we investigate the patterns of Southern Hemisphere temperature change through time
Summary
Stable-isotope ratios of water have been the foundational proxy of polar paleoclimate research for more than a half-century (Langway, 1958; Gonfiantini, 1959; Dansgaard, 1964). Used as a temperature proxy, stratigraphic records of waterisotope ratios in ice sheets provide detailed histories of Earth’s climate over hundreds of thousands of years (Dansgaard et al, 15 1969; Petit et al, 1999), providing insight into the past magnitudes, spatial patterns, and phasing of climate change across the globe (Masson-Delmotte et al, 2006; Barbante et al, 2006; WAIS Divide Project Members et al, 2013, 2015). Both oxygen and hydrogen have stable isotopes whose ratios (18O/16O and 2H/1H) are commonly expressed as deviations, δ18O and δD, from Vienna Standard Mean Ocean Water (VSMOW):. We examine the widely-used assumption of linearity in the scaling relationships between water-isotope ratios and temperature
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
