Japan Geoscience Union Meeting 2022

Presentation information

[J] Oral

M (Multidisciplinary and Interdisciplinary) » M-IS Intersection

[M-IS18] Paleoclimatology and paleoceanography

Fri. May 27, 2022 1:45 PM - 3:15 PM 304 (International Conference Hall, Makuhari Messe)

convener:Hitoshi Hasegawa(Faculty of Science and Technology, Kochi University), convener:Yusuke Okazaki(Department of Earth and Planetary Sciences, Graduate School of Science, Kyushu University), Akitomo Yamamoto(Japan Agency for Marine-Earth Science and TechnologyAtmosphere and Ocean Research Institute), convener:Atsuko Yamazaki(Faculty of Science, Kyushu University), Chairperson:Hitoshi Hasegawa(Faculty of Science and Technology, Kochi University)

2:15 PM - 2:30 PM

[MIS18-25] Polar amplifications in the Cretaceous with changes in atmospheric CO2 concentration and orbital parameters

*Taro Higuchi1, Ayako Abe-Ouchi1, Wing-Le Chan1, Ryouta O'ishi1, Takanori Kodama2 (1.Atmospheric and Ocean Research Institute, the University of Tokyo, 2.The University of Tokyo)


Keywords:polar amplification, Cretaceous

Polar amplification is the phenomenon that external radiative forcing produces a larger change in surface temperature at high latitudes than the global average. Future climate change simulations show a polar amplification with the emission of anthropogenic greenhouse gasses and global warming. Additionally, it is known that, in times like the last interglacial, the orbital parameters different from those in the present day are attributed to a polar amplification in that time ( O'ishi et al., 2021; Otto-Bliesner et al., 2021). Also, Cretaceous proxies indicate remarkable temperature amplifications in the high-latitude and polar region (e.g., Jenkyns et al. 2004 ), resulting in small equator-to-polar temperature difference. Many previous studies have been conducted in order to elucidate the mechanism (Upchurch et al., 2015; Niezgodzki et al., 2017). In this study, we systematically investigated the responses of the polar temperatures in the Cretaceous to changes in atmospheric CO2 concentration and the orbital parameters using an atmospheric-ocean-vegetation fully coupled model MIROC4m-LPJ, and compared it with the proxy data. Additionally, we show the differences of the polar amplifications in the Cretaceous and present-day geographical conditions. Also, change of hydrological cycle is discussed.