Simulating the Last Interglacial Greenland stable water isotope peak:The role of Arctic sea ice changes

• Published in: Quaternary Science Reviews
• Main Authors: Malmierca-Vallet, Irene, Sime, Louise C., Tindall, Julia C., Capron, Emilie, Valdes, Paul J., Vinther, Bo M., Holloway, Max D.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2018
• Subjects: Arctic; Greenland; Renland; GRIP; ice core; Ice Sheet; NGRIP; Sea ice
• Online Access: https://hdl.handle.net/1983/8c04e031-9446-428f-b88f-9b7a809a31fc; https://research-information.bris.ac.uk/en/publications/8c04e031-9446-428f-b88f-9b7a809a31fc; https://doi.org/10.1016/j.quascirev.2018.07.027; http://www.scopus.com/inward/record.url?scp=85052889538&partnerID=8YFLogxK; http://eprints.whiterose.ac.uk/136028/

Last Interglacial (LIG), stable water isotope values (δ 18 O) measured in Greenland deep ice cores are at least 2.5‰ higher compared to the present day. Previous isotopic climate simulations of the LIG do not capture the observed Greenland δ 18 O increases. Here, we use the isotope-enabled HadCM3 (UK Met Office coupled atmosphere-ocean general circulation model) to investigate whether a retreat of Northern Hemisphere sea ice was responsible for this model-data disagreement. Our results highlight the potential significance of sea ice changes on the LIG Greenland isotopic maximum. Sea ice loss in combination with increased sea surface temperatures, over the Arctic, affect δ 18 O: water vapour enriched in heavy isotopes and a shorter distillation path may both increase δ 18 O values over Greenland. We show, for the first time, that simulations of the response to Arctic sea ice reduction are capable of producing the likely magnitude of LIG δ 18 O increases at NEEM, NGRIP, GIPS2 and Camp Century ice core sites. However, we may underestimate δ 18 O changes at the Renland, DYE3 and GRIP ice core locations. Accounting for possible ice sheet changes is likely to be required to produce a better fit to the LIG ice core δ 18 O values.