水循環の強化に関する観測的放射的制約
Anthony M DeAngelis1, Xin Qu1, Mark D Zelinka2
1Department of Atmospheric and Oceanic Sciences, University of California Los Angeles, Los Angeles, California 90095, USA.
Nature
|December 15, 2015
まとめ
気候モデルでは,太陽の吸収を誤って表しているため, 降水量の増加を過大評価しています. これらのモデルの改善により 将来の降雨予測の不確実性が 35% 減少する可能性があります
科学分野:
- 気候科学
- 大気物理学
- 水学
背景:
- 水循環の強化は気候変動の重要な側面であり,人間社会と自然生態系の両方に重大な影響を及ぼしています.
- 水循環の強化の鍵となる指標は,地球温暖化に相関する平均降水量の上昇であり,気候モデルでは3倍の変動を示している (ケルビンあたり1-3%).
- 大気と放射線の相互作用は,このモデルの不確実性の潜在的な源である.
研究 の 目的:
- 気候モデルの予測の不確実性における大気と放射線の相互作用の役割を調査する.
- モデルが大気中の水蒸気に対する太陽吸収の感度とその降雨予測への影響を過小評価しているかどうかを判断する.
主な方法:
- 太陽の吸収,大気中の水蒸気,降水との関係を分析するために,気候モデルのアンサンブルを使用した.
- モデルの拡散への影響を理解するために,モデルの間の放射線伝送パラメータ化の違いを調査した.
主要な成果:
- 気候モデルでは,大気の水分吸収の増加を過小評価する傾向があり,降雨の増加を過大評価する.
- 水蒸気に対する太陽吸収の感度は,異なる放射能伝送方式によりモデルによって大きく変化し,モデルの拡散に大きく寄与する.
- 放射能移転スキームの改善は,予測される地球規模の降雨増加の広がりを約35%減少させることができる.
結論:
- 短波吸収の正確なモデリングは,降雨の気候変動予測の不確実性を減らすために重要です.
- 気候モデルにおける放射性移転スキームの強化は,水循環が温暖化に反応するより信頼性の高い予測につながります.
- この研究は,将来の地球規模の降雨パターンをよりよく理解するために,モデル改善の重要な分野を強調しています.
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