北緯26.5度における大西洋南極逆転循環の時間的変動
Stuart A Cunningham1, Torsten Kanzow, Darren Rayner
1National Oceanography Centre, Empress Dock, Southampton SO14 3ZH, UK. scu@noc.soton.ac.uk
まとめ
大西洋南極の転覆循環 (MOC) は,平均18.7 Sv.で,年ごとに顕著な変動を示しています. 継続的な測定により,その年内の変化が明らかになり,気候変動の影響を理解する上で極めて重要です.
科学分野:
- 海洋学 海洋学 海洋学
- 気候科学 気候科学
- 物理海洋学 物理海洋学
背景:
- 大西洋南極の転覆循環 (MOC) は,地球規模の気候規制に不可欠です.
- MOCの地球温暖化に対する脆弱性は認められていますが,短期的な変動性は依然として十分に理解されていません.
- 以前のMOCの変化評価は,稀なデータに依存しており,十年規模の気候変動の推論を制限していました.
研究 の 目的:
- 大西洋MOCの年内変動を定量化する.
- MOCの年次変動に対する高解像度モニタリング能力を確立する.
主な方法:
- 2004年以来,RAPID (急速気候変動) 配列からの継続的なMOC測定を使用しました.
- ゴルフストリーム輸送と地表層エクマン輸送タイムシリーズからの統合データ.
- トランスアトランティックMOCの評価のために,北緯26.5度に沿って固定された計測器を展開.
主要な成果:
- 年間平均MOC強度は18.7 ± 5.6 sverdrups (Sv) と決定されました.
- 観測されたMOCフローは,4.0から34.9 Sv.の範囲で,著しく変化した.
- 年間間MOCの変化を1.5SVの精度でモニタリングできることを実証しました.
結論:
- MOCの継続的なモニタリングは,短期的な変動に対する前例のない洞察を提供します.
- MOCのダイナミックレンジを理解することは,正確な気候変動影響評価に不可欠です.
- RAPID配列は,気候モデリングに不可欠なMOC変動の堅牢な追跡を可能にします.
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