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Hokkaido University Collection of Scholarly and Academic Papers >
Institute of Low Temperature Science >
低温科学 = Low Temperature Science >
第74巻 >
オホーツク海と北太平洋中層水の数十年スケール変動とそのメカニズム
| Title: | オホーツク海と北太平洋中層水の数十年スケール変動とそのメカニズム |
| Other Titles: | Multi-decadal scale changes in the intermediate water mass in the Sea of Okhotsk and North Pacific and their mechanisms |
| Authors: | 中野渡, 拓也 Browse this author →KAKEN DB | | 三寺, 史夫 Browse this author →KAKEN DB | | 中村, 知裕 Browse this author →KAKEN DB |
| Issue Date: | 31-Mar-2016 |
| Publisher: | 低温科学第74巻編集委員会 |
| Journal Title: | 低温科学 |
| Journal Title(alt): | Low Temperature Science |
| Volume: | 74 |
| Start Page: | 127 |
| End Page: | 141 |
| Abstract: | オホーツク海は北太平洋中層水の主要なヴェンチレーション1 の起源の一つとして，古くからその重要性が指摘されている縁辺海である．近年，北太平洋中層水の塩分が1960 年代から80 年代後半に低下していることが報告されており，その生成源である北太平洋北部の表層塩分の低下が原因と考えられてきた（Wong et al., 1999）．北太平洋亜寒帯域の広い範囲では，表層塩分の低下が観測されており，この仮説を支持する．一方で，北太平洋中層水の中心密度（1026.8 kg/m3）の水塊の主要な形成域であるオホーツク海の観測データの詳細な解析によると，中層水塊は逆に高塩化しており，先行研究の仮説と矛盾する．本報告では，オホーツク海と北太平洋の中層水塊に見られる変化が異なる原因について，海氷・海洋結合モデルによる最新の研究成果について紹介する． | | The Okhotsk Sea is a marginal sea located on the northwest rim of the Pacific Ocean, and is known to be the ventilation source of North Pacific Intermediate Water (NPIW). It has recently been reported that there was a significant freshening of NPIW salinity in the latter half of 20 th century (the water mass was cooled on its isopycnal surfaces) (Wong et al., 1999). Several studies have indicated that freshening in the surface water of the subarctic North Pacific and the Sea of Okhotsk occurs on a multidecadal timescale, implying that freshened source water could modify NPIW. On the contrary, the potential temperature of intermediate water in the Sea of Okhotsk and the western subarctic region increased significantly on 26.8-27.2 σθ isopycnals, which translated to a salinification signal on isopycnal surfaces due to the surrounding T-S curve. In this paper, we present the recent numerical modeling studies focusing on the causes of the multidecadal-scale changes observed in the intermediate water in the Sea of Okhotsk and the North Pacific. |
| Type: | bulletin (article) |
| URI: | http://hdl.handle.net/2115/61207 |
| Appears in Collections: | 低温科学 = Low Temperature Science > 第74巻
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