日本地球惑星科学連合2019年大会

講演情報

[E] ポスター発表

セッション記号 A (大気水圏科学) » A-OS 海洋科学・海洋環境

[A-OS09] 海洋混合学:物質循環・気候・生態系の維持と長周期変動の解明

2019年5月26日(日) 17:15 〜 18:30 ポスター会場 (幕張メッセ国際展示場 8ホール)

コンビーナ:安田 一郎(東京大学大気海洋研究所)、日比谷 紀之(東京大学大学院理学系研究科地球惑星科学専攻)、西岡 純(北海道大学低温科学研究所)、伊藤 進一(東京大学大気海洋研究所)

[AOS09-P07] A comparison of ocean deoxygenation between CMIP5 models and an observational dataset

*阿部 佑美1見延 庄士郎1,5Takamitsu Ito2Curtis Deutsch3Matthew Long4 (1.北海道大学 理学院、2.ジョージア工科大学、3.ワシントン大学、4.アメリカ大気研究センター、5.北海道大学 理学部)

キーワード:北太平洋、北大西洋

Recent studies revealed that the ocean deoxygenation has been accelerating since the 1980s over the global oceans (Schmidtko et al. 2017; Ito et al. 2017), and the observed trend in the last half-century appears to be much larger than the model simulations conducted for CMIP5 (Bopp et al. 2013). This discrepancy is an important issue of the ocean deoxygenation researches as highlighted by a review paper published in the last year (Oschlies et al. 2018).



In order to understand better the relations of oxygen variations between CMIP5 models and observations, we compare oxygen concentration simulated by CMIP5 models and gridded oxygen anomaly dataset used by Ito et al. (2017). For the global oceans, the observed oxygen reduction rate for the historical experiment period appears to be within uncertainty of the models, though this result can be sensitive to the choice of the analysis period associated with the rapid recent oxygen reduction. We also closely examined the two basins that are relatively well sampled, i.e., the North Pacific and the North Atlantic. It is found that the observed North Pacific oxygen reduction is much stronger than the simulated ones, but such a strong reduction of observed oxygen does not occur in the North Atlantic. These results suggest that there are substantial spatio-temporal variations of oxygen concentration on decadal timescales and their mechanism in each basin should be explored in future studies.