观测证据表明,气溶对云层覆盖率较低的气溶对云层覆盖率较低的强迫作用
Tianle Yuan1,2, Hua Song2,3, Robert Wood4
1Goddard Earth Sciences Technology and Research (GESTAR) II, University of Maryland, Baltimore County, Baltimore, MD, USA.
Science advances
|November 8, 2023
概括
气溶通过增强云的亮度和覆盖率 (Cf) 来间接冷却地球,这是气溶间接强迫 (AIF) 的关键因素. 这种云调整对于减少气候模型的不确定性至关重要.
科学领域:
- 大气科学 大气科学
- 气候科学是气候科学.
- 云物理 云物理
背景情况:
- 气溶通过影响云的特性,在地球的能量平衡中发挥关键作用,这一过程被称为气溶间接强迫 (AIF).
- 投资基金的确切规模,特别是来自云调整的贡献,仍然是气候预测中不确定性的重要来源.
- 了解气溶与云之间的相互作用对于准确建模气候敏感性和未来变暖至关重要.
研究的目的:
- 为气溶间接强迫的主要机制提供直接的观察证据.
- 量化云调整,特别是云亮度和覆盖率 (Cf) 对AIF的贡献.
- 研究气溶特性,云特性和由此产生的强迫之间的关系.
主要方法:
- 对观测数据的分析,以评估气溶增加对低云亮度和覆盖率的影响.
- 估计气溶间接强迫 (AIF) 和云调整的贡献.
- 制定一个权力法关系来描述Cf调整作为背景云滴滴数度 (N) 的函数.
主要成果:
- 直接证据表明,云调整 (Cf) 对AIF的贡献很大,而云液态水路调整的影响较弱.
- Cf调整占Twomey效应在海洋上的额外强迫的52%至300%,总AIF为-1.1 ± 0.8 Wm-2 .
- Cf调整显示出电力定律依赖于背景云滴数度 (N),随时间和位置而变化,并且在低N条件下放大,特别是当云开始下雨时.
结论:
- 云亮度和覆盖面 (Cf) 的调整是气溶间接强迫 (AIF) 的主要驱动因素,而不是云液水路径的调整.
- 调整Cf与N的强度定律关系突显了气溶-沉相互作用和不同气溶条件的重要性.
- 专注于Cf调整对于减少AIF的不确定性和改善未来气候预测至关重要.
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