云形成对气溶变化的高度敏感性
Annele Virtanen1, Jorma Joutsensaari1, Harri Kokkola1,2
1Department of Technical Physics, University of Eastern Finland, Kuopio, Finland.
概括
云滴对气溶颗粒的敏感性在低层云中比以前认为的要高. 这一发现影响了气溶间接辐射强迫的估计,并突出了模型的缺陷.
科学领域:
- 大气科学 大气科学
- 气候科学 气候科学
- 气溶科学 气溶科学
背景情况:
- 云滴数度对云凝聚核 (CCN) 数量敏感.
- 这种易感性会影响气溶与云的相互作用和辐射强迫,这是气候变化预测中的关键不确定性.
- 低层层状云是地球辐射平衡的重要贡献者.
研究的目的:
- 为了研究云滴数对低层层层状云中CCN数的易感性.
- 将现场观测与来自卫星的估计和地球系统模型模拟进行比较.
- 根据观测数据量化气溶间接辐射强迫.
主要方法:
- 在三个高度地点利用了气溶和云的长期现场观测 (3-10年).
- 根据观测数据估计的气溶间接辐射强迫.
- 评估了四个地球系统模型与观察数据对敏感性和潜在物理的评估.
主要成果:
- 现场观测显示,与卫星数据相比,在低层层状云中云滴敏感性更高.
- 根据观测,估计气溶间接辐射强迫为-1.16 W m-2,与更高端卫星估计相一致.
- 发现了显著的模型间灵敏度变化,基础物理常常偏离观察结果.
结论:
- 观测到的云滴敏感性表明,气溶与云的相互作用效应比模型中经常表示的更强.
- 这项研究为气溶间接辐射强迫提供了强大的观测约束.
- 这些差异突显出需要在地球系统模型中改进子电网尺度上升速度和气溶尺寸分布表示.
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