温暖化にもかかわらず,グリーンランド氷床の陸地終結セクターの10年間の減速
Andrew J Tedstone1, Peter W Nienow1, Noel Gourmelen1
1School of GeoSciences, University of Edinburgh, Edinburgh EH8 9XP, UK.
Nature
|October 30, 2015
まとめ
グリーンランドの融水は 氷の流れを加速しません この研究では 融水量が50%上昇したにも関わらず 氷の動きが12%減速したことが判明し 氷床の回復力が高まったことを示唆しています
科学分野:
- 氷河学
- 気候科学
- 地球システム科学
背景:
- 氷の流れの動態は,地表の融水によって影響を受けます.
- 融水と氷床の間の水力学的結合は 氷の動きを一時的に加速させることができます
- 氷の流れに対する10年規模の影響は まだ十分に理解されていない.
研究 の 目的:
- グリーンランドの氷床の陸端の氷の動きに対する 10年規模の影響について調査する.
- 表面溶融水の増加が長期にわたって氷の流れにどのように影響するかを評価する.
主な方法:
- 西グリーンランド氷床の8000km2地域における年間氷の移動データを分析した.
- 2つの期間の氷の移動の比較: 1985-94年と2007-14年
- 研究期間中の地表溶融水の生産の変化の定量化
主要な成果:
- 年間氷の移動は1985年から1994年に比べて12%遅かった.
- この減速は,表面溶融水の生産が50%増加したにもかかわらず起こりました.
- 水力学的な結合により 30年以上に渡って 氷の移動が減速しました
結論:
- これまでの仮説とは対照的に,融水の増加は,陸の終端の氷流の純減速につながる可能性があります.
- グリーンランドの氷床の陸端は,以前よりも溶融水のダイナミックな影響に抵抗性があるかもしれません.
- 気候の温暖化による溶融水の増加は,これらのセクターでの氷の動きをさらに減少させる可能性があります.
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