グリーンランドの氷床:高地平衡と周辺の薄まり
1Laboratory for Hydrospheric Processes, NASA Goddard Space Flight Center and EG&G Services, Wallops Flight Facility, Building N-159, Wallops Island, VA 23337, USA. Laboratory for Hydrospheric Processes, NASA Goddard Space Flight Center, Building 33, Room A225, Greenbelt, MD 20771, USA.
Science (New York, N.Y.)
|July 21, 2000
まとめ
グリーンランドの氷床は地域的な変動を示しているが,2000m以上ではバランスが取れている. 低地,特に海岸付近は急速に薄くなっており,海面上昇に貢献しています.
科学分野:
- 氷河学 氷河学とは
- 気候科学 気候科学
- 地球観測 地球観測
背景:
- グリーンランドの氷床の質量バランスは,世界の海面の変化を理解するために重要です.
- 以前の研究では,氷床の動態に関するデータを提供しましたが,包括的な最近の分析が必要です.
研究 の 目的:
- グリーンランドの氷床の最近の質量バランスを,高度測定データを組み合わせて分析する.
- 純氷の減少と海面上昇への貢献を定量化するために.
主な方法:
- グリーンランド北部 (1994年,1999年) の航空機レーザー高度計調査データと,既存のグリーンランド南部データとを組み合わせる.
- 標高2000メートル以上と以下の高さの変化を分析する.
- 年間氷の純損失を推定するためにデータをインターポレーションします.
主要な成果:
- 氷床は平均2000m以上でバランスをとっており,局所的な加厚と薄くなる.
- 1年に1メートルを超える顕著な薄めは,海岸付近の低地で発生します.
- 年間約51立方キロメートルの氷の純損失が推定されていることが判明しました.
結論:
- グリーンランドの氷床は,主に低地での質量を失っています.
- この氷の減少は,世界の海面上昇に大きく寄与し,観測された上昇の約7%を占めています.
- 気候変動に対する氷床の反応を追跡するには,継続的なモニタリングが不可欠です.
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