Kauri tree‐ring stable isotopes reveal a centennial climate downturn following the Antarctic Cold Reversal in New Zealand

• Published in: Geophysical Research Letters
• Main Authors: Pauly, M., Turney, C.s.m., Palmer, J.g., Büntgen, U., Brauer, A., Helle, G.
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Geophysical Union 2021
• Subjects: delta C-13; delta O-18; climate; Late Glacial; New Zealand; tree-ring cellulose; Antarctic; The Antarctic; Antarc*
• Online Access: https://archimer.ifremer.fr/doc/00665/77698/79777.pdf; https://archimer.ifremer.fr/doc/00665/77698/79778.docx; https://doi.org/10.1029/2020GL090299; https://archimer.ifremer.fr/doc/00665/77698/

The dynamics of the Late Glacial (LG) have been demonstrated by numerous records from the Northern Hemisphere (NH) and far fewer from the Southern Hemisphere (SH). SH paleoclimate records reveal a general warming trend, interrupted by a deglaciation pause (ACR: Antarctic Cold Reversal, ∼14,700 – 13,000 cal BP). Here we present decadal tree‐ring stable isotope chronologies (δ18O, δ13C) from New Zealand (NZ) subfossil kauri trees (n=6) covering the post‐ACR millennium from 13 020 – 11 850 cal BP. We find a distinct, simultaneous downturn (∼12 625 – 12 375 cal BP) in all tree‐ring proxies paralleling regional tree growth declines, suggesting a widespread climate deterioration. This downturn was characterised by sustained high precipitation, low temperatures and high relative humidity in NZ with incoming weather fronts from the South Ocean. Despite these promising results, questions remain about what drove the Kauri Downturn and how the hydroclimatic conditions were altered during this time period.