グリーンランドの床の弱まりを促す
Nathan Maier1, Florent Gimbert2, Fabien Gillet-Chaulet2
1Université Grenoble Alpes, CNRS, IGE, Grenoble, France. ntmaier@gmail.com.
Nature
|July 27, 2022
まとめ
グリーンランド
科学分野:
- 氷河学
- 気候科学
- 地球システム科学
背景:
- 氷床の動態は主に氷床の接点にある 融水によって制御されます
- 融水が増えると 氷の下の排水が強化され 摩擦が増加し 氷の流れが遅くなり 融化による質量損失が制限されます
研究 の 目的:
- グリーンランドの氷床の動態に対する 融水の影響の主な要因を調査する
- グリーンランド西部における摩擦の変動性と,その融解力との関係を分析する.
主な方法:
- 氷床全体の摩擦の変動を評価するための新しい方法を開発しました.
- 床の強度に対する融解効果を分析し,基礎水貯蔵と排水経路と関連付けました.
主要な成果:
- 融解の強制は,床の強さの北から南への重要なシフトを引き起こしますが,それは融解率によって直接説明されません.
- グリーンランドの南部は基礎水貯蔵により弱体化 (20~40%),北部は強体化している.
- 床の弱化は,陸と海の境界によって制御される滑り,水力潜在気流と関連しています.
結論:
- 氷床のダイナミクスは 融解速度にのみ依存するものではなく 基礎水貯蔵とマージンタイプが 重要な要素です
- 温度の上昇に伴い,ダイナミックな変化による質量損失が増える可能性が高い.
- 発見は,より正確な百年スケールの氷床の進化モデリングのための改善された物理的表現を必要とします.
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