アメリカ合衆国西部における長期的干ばつ変化
Edward R Cook1, Connie A Woodhouse, C Mark Eakin
1Lamont-Doherty Earth Observatory, Palisades, NY 10964, USA. drdendro@ldeo.columbia.edu
Science (New York, N.Y.)
|October 9, 2004
まとめ
現在のアメリカ西部の干ばつが深刻ですが,歴史的なデータは,紀元900年から1300年の間にさらに極端な干ばつが起こったことを示しています. 将来の温暖化は,北米西部の長期的干ばつを増やす可能性があります.
科学分野:
- 古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは
- 気候科学 気候科学
- 水文学 水文学とは
背景:
- 米国西部は現在,多年にわたる深刻な干ばつに直面しています.
- この干ばつの深刻さは,最近の水気気候記録の中で顕著です.
研究 の 目的:
- 米国西部の過去の干ばつ状況を再構築し,分析する.
- 現在の干ばつを歴史的な干ばつ現象と比較するために.
主な方法:
- 米国西部で1200年に及ぶ干ばつ再建をグリッドで利用した.
- 乾燥度が高い時期を特定するために,古気候データを分析した.
主要な成果:
- 現在の干ばつが,紀元900年から1300年までの壮大な干ばつ期間の干ばつ期に比べ,それほど深刻ではない.
- この初期の極度の乾燥期は,中世の温暖期と一致しています.
結論:
- 米国西部の乾燥度が高まっていることは,気候変動への自然な反応かもしれない.
- 将来の温暖化傾向は,北米西部の乾燥が長期的に大幅に増加する可能性がある.
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