[A-CG48] [EJ] 北極域の科学

[ACG48-P03] The role of vegetation change upon polar amplification in warm climate by feedback analysis

*大石 龍太¹、吉森 正和²、阿部 彩子^1,3 (1.東京大学大気海洋研究所、2.北海道大学、3.海洋開発研究機構)

キーワード：極域増幅、植生、古気候

Previous studies revealed that vegetation change in high latitude (e.g. from tundra to forest) in warm climate strengthen a polar amplification. This is due to lower vegetation albedo of forest then tundra, snow-albedo feedback caused by early snow melt due to forest coverage and ocean heat emission in autumn and winter. In the present study, we run a vegetation–coupled general circulation model with a slab-ocean, MIROC-LPJ, for two kinds of warming experiments. One is due to higher atmospheric CO2 concentration (2xCO2 and 4xCO2) and the other is due to the difference of the Earth’s orbit (mid-Holocene and the Last Interglacial). The result shows different mechanisms of warming amplification between CO2-induced vegetation feedback and orbit-induced vegetation feedback. We also try to apply a feedback analysis (Cai and Luo 2009; Yoshimori et al. 2014) to result of MIROC-LPJ experiments.