Past Antarctic summer temperature revealed by total air content in ice cores

• Main Authors: Raynaud, Dominique, Yin, Qiuzhen, Capron, Emilie, Wu, Zhipeng, Parrenin, Frederic, Berger, André, Lipenkov, Vladimir
• Other Authors: UCL - SST/ELI/ELIC - Earth & Climate
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2023
• Subjects: Antarctic; Tac; The Antarctic; Antarc*; ice core; Ice Sheet
• Online Access: http://hdl.handle.net/2078.1/282188; https://doi.org/10.5194/egusphere-2023-2360

Seasonal temperature reconstructions from ice cores are missing over glacial-interglacial timescales, preventing a good understanding of the driving factors of Antarctic past climate changes. Here the total air content (TAC) record from an Antarctic ice core is analyzed over the last 440 thousand of years (ka). While the water isotopic record, tracer for annual mean surface temperature, exhibits a dominant ~100 ka cyclicity, the TAC record is associated with a dominant ~40 ka cyclicity. Our results show that the TAC record is highly correlated with the mean insolation over the local astronomical half-year summer. It also shows for the first time that it is highly correlated with local summer temperature simulated with an Earth system model of intermediate complexity. This suggests that the Antarctic TAC records could be used as a proxy for local summer temperature changes. Also, our simulations show that local summer insolation is the primary driver of Antarctic summer surface temperature variations while changes in atmospheric greenhouse gas concentrations and northern hemisphere ice sheet configurations play a more important role on Antarctic annual surface temperature changes.