EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Effect of Climatic Precession on Dansgaard-Oeschger-like oscillations 

Yuta Kuniyoshi1, Ayako Abe-Ouchi1,2,3, Sam Sherriff-Tadano1, Wing-Le Chan1, and Fuyuki Saito2
Yuta Kuniyoshi et al.
  • 1the University of Tokyo, AORI, Japan (
  • 2The Japan Agency for Marine-Earth Science and Technology , Yokohama, Japan
  • 3National Institute of Polar Research, Tokyo, Japan

Using the climate model MIROC4m, we simulate self-sustained oscillations of millennial-scale periodicity in the climate and Atlantic meridional overturning circulation under glacial conditions. We show two cases of extreme climatic precession and examine the mechanism of these oscillations. When the climatic precession corresponds to strong (weak) boreal seasonality, the period of the oscillation is about 1,500 (3,000) years. During the stadial, hot (cool) summer conditions in the Northern Hemisphere contribute to thin (thick) sea ice, which covers the deep convection sites, triggering early (late) abrupt climate change. During the interstadial, as sea ice is thin (thick), cold deep-water forms and cools the subsurface quickly (slowly), which influences the stratification of the North Atlantic Ocean. We show that the oscillations are explained by the internal feedbacks of the atmosphere-sea ice-ocean system, especially subsurface ocean temperature change and salt advection feedback with a positive feedback between the subpolar gyre and deep convection.

How to cite: Kuniyoshi, Y., Abe-Ouchi, A., Sherriff-Tadano, S., Chan, W.-L., and Saito, F.: Effect of Climatic Precession on Dansgaard-Oeschger-like oscillations , EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-6750,, 2022.


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