南半球の西風の極移りによるアジュラスの漏れの増加
A Biastoch1, C W Böning, F U Schwarzkopf
1Leibniz-Institut für Meereswissenschaften, Düsternbrooker Weg 20, 24105 Kiel, Germany. abiastoch@ifm-geomar.de
Nature
|November 27, 2009
まとめ
大西洋に流入する温かいインド洋の水が増加し,世界の海洋循環に影響を与えています. このアギュラスの漏れは,大西洋南極反転循環 (MOC) の熱と塩分を変化させることで気候に影響します.
科学分野:
- 海洋学 海洋学 海洋学
- 気候科学 気候科学
- 海洋循環 海洋循環
背景:
- インド洋の水を大西洋に運ぶアギュラスの漏れは,世界の海洋循環と気候に不可欠です.
- これらの水域は,大西洋南極反転循環 (MOC) の熱と塩の主要な源泉です.
- 過去の気候記録は,アジュラスの漏れとMOCが南半球の西風のシフトによって変化した可能性があることを示唆しています.
研究 の 目的:
- Agulhasの漏洩の最近の変化を調査するために.
- 人為的なフォースリングによる西風の変化がアグルハスの漏れに影響を与えているかどうかを判断する.
- アグルハスの漏れが増えたことによる大西洋の塩分とMOCへの影響を評価する.
主な方法:
- 高解像度の海洋一般循環モデルを使用した.
- 過去数十年にわたる風力力の変化を分析した.
- モデルの出力を,南米沖の過去の測定値と比較した.
主要な成果:
- このモデルは,過去数十年にわたってアグルハスの南大西洋への漏れが著しく増加したことを示しています.
- この増加は,地域の風力強制力の変化と直接関連しています.
- 漏れが増加したことで,南大西洋の熱クリン水域の塩化が進んでいる.
結論:
- アギュラスの漏れの増加は,風のパターンの変化によって引き起こされる最近の現象です.
- 証拠によると,これらのインド洋の水は,現在北大西洋に流れ込んでいます.
- これは,大西洋南極反転循環 (MOC) の将来の安定性と進化に潜在的な影響を及ぼします.
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