日本地球惑星科学連合2014年大会

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ポスター発表

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

[A-CG36_30PO1] 北極域の科学

2014年4月30日(水) 18:15 〜 19:30 3階ポスター会場 (3F)

コンビーナ:*齊藤 誠一(北海道大学大学院水産科学研究院)、猪上 淳(国立極地研究所)、原田 尚美((独)海洋研究開発機構)、鈴木 力英(海洋研究開発機構 地球環境変動領域)

18:15 〜 19:30

[ACG36-P06] SF6によるカナダ海盆における太平洋冬季水の水塊年齢の分布

*荻原 佑介1川合 美千代2 (1.東京海洋大学 大学院 海洋科学技術研究科、2.東京海洋大学 先端科学技術研究センター)

キーワード:北極海, 時系列トレーサー, 六フッ化硫黄, 海洋循環

In the Pacific sector of the Arctic Ocean, Pacific Winter Water (PWW) distributes between 100m and 200m depths. Because the PWW has high nutrient concentrations and low pH, its spreading pathway has implications on primary production and ocean acidification in the Arctic Ocean. In this study, we have observed distribution of SF6, a transient tracer alternative to CFCs, in order to trace newly formed PWW into the Canada Basin.
Sampling was carried out in summer of 2013 on the CCGS Louis S. St-Laurent. Seawater at the core of PWW (salinity = 33.1) were collected in Niskin bottles and then transferred into custom-made glass bottles. Samples were kept at low temperature and brought back to Japan. Concentrations of SF6 in seawater samples were determined by an ECD-GC following the method described in Bullister and Wisegarver (2008).
Results show that younger PWW distributes at the periphery of the Beaufort Gyre, a major anticyclonic circulation in Canada Basin. The age of PWW estimated from SF6 was 13〜15 years in the center of the gyre, whereas age was 6〜9 years around the gyre. From the distributions of SF6 age, dissolved oxygen and nutrients, it is suggested that there is a pathway of PWW from the Siberian shelves or slopes into the northeastern Canada Basin.