最近のグリーンランド氷河の大量減少は,衛星による重力観測からの排水システムによるものです
S B Luthcke1, H J Zwally, W Abdalati
1Planetary Geodynamics Laboratory, Code 698, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA. Scott.B.Luthcke@nasa.gov
まとめ
グリーンランドの氷床は,2003年から2005年にかけて毎年101ギガトンの氷を失っているが,これは主に低地での損失である. これは,1990年代のほぼ均衡状態からの大きな変化を示しています.
科学分野:
- * 氷河学と気候科学
- * 地球観測と地球物理学
背景:
- * グリーンランドの氷床の質量バランスは,世界の海面上昇を理解するために重要です.
- * 以前の氷の減少の推定値は変動しており,地域分析の精細化が必要となった.
研究 の 目的:
- * 地域の排水システムデータを用いてグリーンランド氷床の質量変化を定量化する.
- * 2003年から2005年にかけての氷の質量減少の空間的および時間的なパターンを分析する.
主な方法:
- * グラビティ・リカバリー・アンド・クライマート・エクスペリメント (GRACE) ミッションの観測結果のローカル・マス・コンセントレーション分析を利用した.
- * グリーンランドの氷床の特定の排水システム地域による質量変化の解像度.
主要な成果:
- * 総氷の損失は2003年から2005年の間に年間平均101 +/- 16ギガトンであった.
- * 低地では,顕著な季節のサイクルで,かなりの質量損失 (155ギガトン/年) を経験しました.
- *高地 (2000メートル以上) では,年間54ギガトンの増量が見られた.
結論:
- * グリーンランドの氷床は,2003年から2005年にかけて実質的な負質量バランスを示し,1990年代から顕著な変化を示した.
- *地域分析では,質量変化のパターンがはっきりと示され,低地層は全体的な氷の減少に大きく寄与している.
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