ラブラドール海とアーミンガー海の中部で直接速度測定で観測された中深度の循環
1Scripps Institution of Oceanography, University of California, San Diego, La Jolla 92093-0230, USA. klavender@ucsd.edu
Nature
|September 19, 2000
まとめ
地下浮遊は,ラブラドール海における予期せぬ海流を明らかにし,ラブラドール海水の形成と広がりに関する以前のモデルに挑戦しています. これらの発見は,北大西洋における熱ハリン循環の複雑なダイナミクスを強調しています.
科学分野:
- 海洋学 海洋学とは
- 物理海洋学 物理海洋学
- 気候科学 気候科学
背景:
- ラブラドール海は,深海のコンベクションと熱ハリン循環の重要な場所です.
- ラブラドール海の水は,冷たく新鮮な性質で特徴付けられており,北大西洋全体で中間の深さで追跡できます.
- この分布を動かす海流の直接観測は,データ不足のために歴史的に困難でした.
研究 の 目的:
- ラブラドール海とアーミンガー海における盆地全体の水平速度を,地下浮遊船を用いて直接測定する.
- ラブラドール海水の広がりの経路とダイナミクスを調査する.
- 地域における熱ハリン循環に関する現在の理解を再評価する.
主な方法:
- 200以上の地下浮き船を展開する.
- 海流の速度を様々な深さで直接測定する.
- 水質の移動をマッピングするために浮遊軌道の分析.
主要な成果:
- ラブラドール海とアーミンガー海の中央深度の境界流における予期せぬ再循環が観察されました.
- ラブラドール流域の内部のアンチサイクロン流れを特定しました.
- 深いコンベクションによる水の約40%が1年以内に流域を去り,迅速にアーミンガー流域と亜極回転に運ばれることを発見しました.
- 周回流は,明確な深い西の境界流ではなく,フレミングキャップの近くの流れを支配し,沖合に水を運ぶことに注意した.
結論:
- この研究は,ラブラドール海水の形成と拡散に関する確立されたモデルの改訂を提案しています.
- 観測された海洋循環パターンは,以前の予想とは大きく異なる.
- 中間深度の海洋循環を完全に理解するために,同様の計器を用いたさらなる研究が必要である.
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