日本地球惑星科学連合2019年大会

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[J] ポスター発表

セッション記号 A (大気水圏科学) » A-CG 大気海洋・環境科学複合領域・一般

[A-CG40] 沿岸海洋生態系─1.水循環と陸海相互作用

2019年5月28日(火) 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:藤井 賢彦(北海道大学大学院地球環境科学研究院)、山田 誠(龍谷大学経済学部)、小路 淳(東京大学大気海洋研究所)、杉本 亮(福井県立大学海洋生物資源学部)

[ACG40-P05] Assessment and future projection of variational characteristics of ocean warming and acidification proxies in Oshoro Bay, Japan

*藤井 賢彦1山家 拓人2高尾 信太郎3 (1.北海道大学大学院地球環境科学研究院、2.北海道大学大学院環境科学院、3.国立極地研究所)

キーワード:海洋酸性化、地球温暖化、亜寒帯、沿岸域、pH、炭酸カルシウム飽和度

As ocean acidification proceeds, it is concerned difficult for calcium carbonate and magnesium carbonate to be produced in the ocean, and calcifying organisms such as corals and shellfish having these skeletons and shells may be adversely affected. Moreover, the diurnal, seasonal and interannual fluctuation are all considered more prominent in coasts than in the open ocean, because of relatively larger amount of sea grass beds and more direct and significant terrestrial impacts. On the other hand, in the subarctic coastal region, it is difficult to maintain observation due to stormy weather in winter, which yields paucity of observational data. In this study, long-term continuous monitoring of physical and biogeochemical parameters was conducted in Oshoro Bay, Otaru City, Hokkaido. Our results show that the timing of increase and decrease of pH and dissolved oxygen almost coincided with each other, and the diurnal variation of pH was larger in spring and summer than in fall and winter. The diurnal variation of pH was 0.1 or more on average from May to August. The variation was 0.15 on average and 0.26 at the maximum, respectively, in August. That was 0.03 on average and 0.07 at the maximum, respectively, in November. Thus, the seasonal difference in the diurnal variation was clear, suggesting significant effects of the photosynthesis in the daytime and the respiration in the nighttime by primary producers. The results suggest relatively predominant biological effects with larger biomass and higher solar radiation in summer compared to those in winter. Results of the temporal variability of the ocean warming and acidification proxies obtained by applying the Regional Ocean Model System (ROMS) to the site will be introduced in the presentation.