南大洋の深淵の海域では,高混合率である
Karen J Heywood1, Alberto C Naveira Garabato, David P Stevens
1School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ, UK. k.heywood@uea.ac.uk
Nature
|March 5, 2002
まとめ
スコシア海 (Scotia Sea) は,大きな深海盆地で,大洋の混合が観察されました. この発見は,深海の水がどのように上向きに移動するかを説明するのに役立ちますが,これは地球規模の海洋循環の重要なプロセスです.
科学分野:
- 海洋学 海洋学とは
- 流体力学 流体力学とは
- 気候科学 気候科学
背景:
- グローバルな海洋の逆転循環は,深海の水質を上層層に混ぜることで成り立っている.
- 観測された盆地平均の拡散性は,地球規模の上向きの水流の説明には不十分である.
- 激しい混合は,通常,スリーブや狭い隙間付近の領域に限定されます.
研究 の 目的:
- スコシア海 (Scotia Sea) の混合強度を調査し,定量化するために,大規模な深海の盆地.
- スコシア海が盆地全体の海洋混合に有意に寄与しているかどうかを判断する.
- スコチア海の役割を理解するために,地球規模で流れる深淵の水質の上昇.
主な方法:
- スコシア海流域全体の予算計算方法を使用しています.
- 粗な地形が特徴である深海の盆地からの海洋学的データを分析する.
- 海洋転覆循環の連続性に基づいて拡散性を推定する.
主要な成果:
- スコチア海の広範囲で,前例のない高混合強度の発見.
- 計算された盆地全体の拡散度 (39 ± 10) x 10^4 m^2/s 7 x 10^5 km^2.2 にわたって
- スコティア海は,深水の質量混合の重要な場所として特定.
結論:
- スコシア海は,盆地全体で非常に高い混合を呈しており,混合強度の分布に関する以前の仮定に異議を唱えています.
- スコシア海におけるこの高混合強度は,深淵の水の上向き輸送に決定的な役割を果たしている可能性が高い.
- この発見は,南大洋の水質が水面に向かって混ざり合っているという長年の問題を解くのに寄与する.
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