人类和自然强迫因素对近期热带期高度变化的贡献
B D Santer1, M F Wehner, T M L Wigley
1Program for Climate Model Diagnosis and Intercomparison, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA. santer1@llnl.gov
Science (New York, N.Y.)
|July 26, 2003
概括
自1979年以来,分离地球大气层的热带层已经显著上升. 气候模型显示,人类活动,主要是臭氧变化和温室气体,是造成这种增长的原因.
科学领域:
- 大气科学 大气科学
- 气候变化研究 气候变化研究
- 地球系统科学 地球系统科学
背景情况:
- 自1979年以来,热带层和平流层之间的边界,热带层的高度显著增加.
- 气候模型模拟了热带期高度的相似增加,这表明与外部强迫因素的联系.
研究的目的:
- 为了调查所观察到的热带期高度上升背后的驱动因素.
- 将热带期高度的变化归因于特定的人类和自然因素.
- 用观测数据验证气候模型模拟.
主要方法:
- 从1979年起对观测数据 (再分析数据集) 的分析.
- 利用气候模型实验模拟大气变化.
- 在观测数据中统计检测模型预测的"指纹".
主要成果:
- 自1979年以来,热带气候的高度增加了几百米.
- 气候模型表明,臭氧层消耗和混合良好的温室气体约占模拟增长的80%.
- 平流层冷却 (由于臭氧) 和热层变暖 (由于温室气体) 是主要的机制.
- 模型预测的变化可以在观测数据中统计检测到.
结论:
- 观测到的热带期高度的增加是由于人为和自然外部强迫因素的结合造成的.
- 人为因素,特别是臭氧变化和温室气体排放,是热带期高度增加的主要驱动因素.
- 这项研究为人类对大气结构的影响提供了有力的证据.
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