日本地球惑星科学連合2023年大会

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[J] 口頭発表

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-CG46] 北極域の科学

2023年5月24日(水) 10:45 〜 12:00 103 (幕張メッセ国際会議場)

コンビーナ:両角 友喜(国立環境研究所)、島田 利元(宇宙航空研究開発機構)、堀 正岳(東京大学大気海洋研究所)、川上 達也(北海道大学)、座長:両角 友喜(国立環境研究所)、川上 達也(北海道大学)、島田 利元(宇宙航空研究開発機構)

10:45 〜 11:00

[ACG46-01] Water modification in the Barents Sea in a high-resolution ice-ocean model

*川崎 高雄1小室 芳樹2小野 純2 (1.東京大学 大気海洋研究所、2.海洋研究開発機構 北極環境変動総合研究センター)

キーワード:バレンツ海、海洋モデリング、水塊形成

Barents Sea Water (BSW) inflows to the intermediate layer in the Arctic Ocean and has impacts on the sea ice and climate system in the Arctic region. A lack of understanding of the mechanisms of BSW formation and inflow processes causes the bias of temperature and salinity in the Arctic Ocean even in state-of-art climate models. The Barents Sea Water is formed by the modification of the Atlantic Water caused by the sea surface cooling and mixing with the surface Polar Water. The quantitative estimate of the formation of Barents Sea Water is conducted by an ocean model.
An ice-ocean general circulation model named COCO is utilized in this study. The horizontal grid size spatially varies by placing the poles of the general curvilinear horizontal coordinates close to the Barents Sea. The horizontal grid size is 2-8 km in the Barents Sea. The model is integrated from 1980 to 2020 under the 3-hourly sea surface condition dataset (JRA55-do). The nudging of sea surface salinity is not applied to represent freshening seawater in this model. The temperature, salinity, and their decreases in the Barents Sea are well reproduced in our model. Sea surface cooling is the dominant process in water modification in the southern Barents Sea. The cooled Atlantic Water gets buoyancy due to mixing with sea-ice melting water near the surface in the northern and northeastern Barents Sea. The decrease of the sea surface cooling in the southern Barents Sea and the warming of BSW inflowing the Arctic Ocean are simulated in the 2010s.