極地オゾン層の劣化が亜熱帯雨量に与える影響
S M Kang1, L M Polvani, J C Fyfe
1Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY, USA. smk2182@columbia.edu
Science (New York, N.Y.)
|April 23, 2011
まとめ
オゾン層の減少は南半球のジェットストリームをシフトさせ,亜熱帯の降雨パターンを大幅に変えました. この研究は,極地オゾン層の減少と南亜熱帯の降雨量の増加を関連付け,世界の水循環に影響を与えています.
科学分野:
- 大気科学 大気科学
- 気候科学 気候科学
- 水文学 水文学とは
背景:
- オゾンホールは,南半球の外熱帯の西のジェットポールを過去50年にわたって明らかに移動させた.
- エクストラトロピカル循環の変化は,より広範な気候パターンへの影響としてますます認識されています.
研究 の 目的:
- オゾン層の枯渇によって引き起こされる循環の変化と亜熱帯の降雨の間の因果関係を調査する.
- 観測された亜熱帯降雨傾向に対する極地オゾン層の減少の寄与を定量化するために.
主な方法:
- 南半球の循環を極性オゾン減少条件下でシミュレートするために気候モデルを使用した.
- 降水変化のモデル出力を,1979年から2000年までの観測データと比較した.
主要な成果:
- 気候モデルでは,オゾン層の劣化が考慮されているオーストラリアの夏の間,南部の亜熱帯雨量の大幅な増加を示しています.
- 1979年から2000年までの観測された亜熱帯降雨パターンは,オゾン層の枯渇のみによって引き起こされるモデルシミュレーションに非常に似ています.
- モデルデータと観測データの両方が,亜熱帯の加湿を,熱帯外西部ジェットの極方向のシフトと関連付けています.
結論:
- 北極オゾン層の減少は,南半球における亜熱帯雨量の変化の重要な要因である.
- オゾンによって影響される,熱帯外の西のジェットの極方向のシフトは,亜熱帯の水理学を調節する上で重要な役割を果たします.
- 極地地域は,亜熱帯地域の水循環に大きな影響を与えます.
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