EGU21-8145
https://doi.org/10.5194/egusphere-egu21-8145
EGU General Assembly 2021
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Antarctic warmth in the last interglacial driven by Northern insolation and deglaciation

Takashi Obase1, Ayako Abe-Ouchi1,2, and Fuyuki Saito3
Takashi Obase et al.
  • 1The University of Tokyo, Atmosphere and Ocean Research Institute, Kashiwa, Chiba, Japan (obase@aori.u-tokyo.ac.jp)
  • 2National Institute of Polar Research Institute, Japan
  • 3Japan Agency for Marine-Earth Science and Technology

The global mean sea level in the last interglacial (LIG, about 130,000 to 115,000 years before present) was very likely higher than the present level, driven mainly by mass loss of the Antarctic ice sheet. Some studies have suggested that this mass loss may have been caused by the warmer temperature over the Southern Ocean in the LIG compared with the present interglacial. However, the ultimate cause of the difference in Antarctic warming between the last and current interglacials has not been explained. Here, based on transient simulations of the last deglaciation using a fully coupled ocean–atmosphere model, we show that greater meltwater (by a factor of 1.5 relative to the last deglaciation) during the middle and later stages of the deglaciation could have produced the difference in Antarctic warmth. Northern Hemisphere ice sheet model experiments suggest that the difference in meltwater was caused by slightly smaller orbital eccentricity in our current interglacial than in the LIG, indicating that mass loss of the Antarctic ice sheet is influenced by the preceding northern summer insolation and disintegration of Northern Hemisphere ice sheets.

How to cite: Obase, T., Abe-Ouchi, A., and Saito, F.: Antarctic warmth in the last interglacial driven by Northern insolation and deglaciation, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-8145, https://doi.org/10.5194/egusphere-egu21-8145, 2021.

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