南極大陸の海面上昇への寄与の衛星重力測定による下位推定値
Matt A King1, Rory J Bingham, Phil Moore
1School of Civil Engineering and Geosciences, Newcastle University, Newcastle upon Tyne NE1 7RU, UK. m.a.king@newcastle.ac.uk
Nature
|October 23, 2012
まとめ
南極大陸は南極で
科学分野:
- 地球科学 地球科学 地球科学
- 氷河学 氷河学とは
- 気候科学 気候科学
背景:
- 南極の氷の質量減少の推定は大きく異なっており,海面上昇の予測に影響を及ぼしている.
- 氷河同静調整 (GIA) モデルの不確実性は,重力回復と気候実験 (GRACE) 衛星データ解釈に大きく影響する.
研究 の 目的:
- 新しいGIAモデルを使用して,南極の氷の質量変化の見積もりを精査する.
- GIAの不確実性に対処することによって,GRACEから派生した氷の質量損失データの精度を向上させる.
主な方法:
- 地質学的制約に基づいた新しいGIAモデルを開発し,より低いGIAレートを得ました.
- 新しいGIAモデルを99ヶ月のGRACE衛星データ (2002年8月~2010年12月) に適用しました.
- 26の独立した南極の排水盆地における氷の質量の変化を分析した.
主要な成果:
- 大陸全体の氷の質量の変化が -69 ± 18 Gt yr ((-1) (+0.19 ± 0.05 mm yr ((-1) 海平面相当) と推定されています.
- この推定値は,古いGIAモデルを使用した以前のGRACEベースの推定値よりも大幅に低い.
- 氷の質量減少と加速は,アムンセン海沿岸盆地に集中している. 西南極はバランスの近く,東南極は質量が増えている.
結論:
- 新しいGIAモデルは,GRACEから派生した氷の質量変化の推定値の不確実性を大幅に削減します.
- 南極大陸の海面上昇への貢献はより正確に定量化され,地域の変動が強調されています.
- 将来の海面上昇予測は,南極の氷の動態に関するより正確なデータで改善することができます.
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