20世紀における世界の海面上昇への質量と体積の貢献
Laury Miller1, Bruce C Douglas
1Laboratory for Satellite Altimetry, NESDIS, NOAA, Silver Spring, Maryland 20910, USA. laury.miller@noaa.gov
Nature
|March 26, 2004
まとめ
潮位計による世界の海面上昇の推定値は,海洋温暖化によるものよりも高い. この研究は,熱膨張ではなく,氷床の融解が,20世紀の海面上昇の主な要因であると示唆しています.
科学分野:
- * 気候科学 気候科学
- * 海洋学について
- * 氷河学 氷河学
背景:
- *20世紀における世界の海面上昇は議論の的であり,潮位計のデータ (1.5-2.0 mm yr−1) は間接的な推定値と矛盾している.
- *間接的な推定では,海面上昇を海洋熱膨張 (約. 0.5 mm yr−1) と氷の融解,氷の融解の貢献はより小さいと考えられています.
- *不一致は,潮位計のデータが膨らんだか,または質量/体積変化の貢献が過小評価されていることを示唆しています.
研究 の 目的:
- *世界の海面上昇率とその原因に関する矛盾する見積もりを調和させる.
- * 海洋温暖化と氷の融解が海面上昇に与える相対的な影響を調査する.
- * 潮位計の測定を海洋学データと比較して検証する.
主な方法:
- * 潮位計の海水位測定の分析.
- *太平洋と大西洋の海洋温度と塩分データを統合.
- * 海洋学データから得られた海量変化率とゲージで決定された海面上昇の比較.
主要な成果:
- *ゲージで決定された海面上昇率は,温度/塩分データからの体積変化率より2〜3倍高い.
- *この調査結果は,20世紀における海面上昇を年間1.5~2.0mmという以前の推定を裏付けている.
- * 氷河の融解による質量増加は,海洋温暖化よりも重要な要因として示されています.
結論:
- *潮位計のデータは,海面上昇に寄与する質量と体積の変化を正確に反映しています.
- * 20世紀における世界の海面上昇に対する大陸氷の融解の寄与は大きい.
- * 20世紀における海面上昇における海洋温暖化の役割は,以前に推定されたものより重要ではないかもしれない.
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