ホロセーン時代の米国北東部におけるミレニアムスケールの嵐の変動
Anders J Noren1, Paul R Bierman, Eric J Steig
1Department of Geology, University of Vermont, Burlington, Vermont 05405, USA. anders.noren@alumni.carleton.edu
Nature
|October 25, 2002
まとめ
豪雨のような極端な嵐は,過去1万3千年の間,3,000年周期で定期的に発生しています. 北米とヨーロッパのこのパターンは,主要な気候要因である北極振動の変化と関連しています.
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,古代気候学 (paleoclimatology) とは
- 気候科学 気候科学
- 四次地質学 四次地質学
背景:
- 天然の気候変動の変動を文書化することは,気候変動に対する人間の影響を理解するために極めて重要です.
- 激しい降雨嵐などの過去の極端な気候現象の研究は,重大な課題を提示しています.
- 単一の湖の堆積物コアを使用した以前の方法は,地元の環境バイアスによって制限されています.
研究 の 目的:
- 過去の嵐を復元し,長期的な変動パターンを特定する.
- ホロセンの気候の変動に対する大気モードの影響を調査する.
- 過去1万3千年の米国北東部における嵐の年代を定めるため.
主な方法:
- 13つの湖から収集された堆積物コアからの土着のインウォッシュ層の分析.
- 堆積物核の年代測定は,過去の出来事の正確なタイムラインを確立するために行われます.
- 嵐の頻度データと長期の気候振動の相関.
主要な成果:
- 米国北東部の嵐による洪水の頻度は,過去1万3千年にわたって定期的に変化しており,その周期は約3000年です.
- 過去1万4000年の間に4つの異なる嵐のピークが特定されました.
- 観測された嵐のパターンは,北極振動の長期的な変化と一致しています.
結論:
- 極端な嵐の発生頻度は,主要な大気モードの影響を受ける周期的なパターンを表しています.
- 北極振動は,北米とヨーロッパにおけるホロセンの気候の変動を調節する上で重要な役割を果たしています.
- この研究は,過去の嵐活動の堅固な,複数の湖の再構築を提供し,単一サイトの研究の限界を克服します.
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