论文标题
通过近乎全球云模型模拟地球长期气候的云反馈
Cloud Feedback on Earth's Long-term Climate Simulated by a Near-global Cloud-permitting Model
论文作者
论文摘要
随着时间的流逝，太阳变得更加光明，但是地球的气候在其长期历史上大致延续了生命。对于早期地球而言，这被称为淡淡的年轻太阳问题（FYSP）。除了碳酸盐 - 硅酸盐反馈外，最近的研究表明，长期的云反馈可能部分解决了FYSP。但是，他们使用的一般循环模型无法明确解决对流和云。这项研究使用近乎全球云的模型对云进行了重新研究，而无需积云对流参数化。我们的结果证实，确实存在稳定的短波云反馈，其幅度为$ \ $ \ $ 6 w m $^{ - 2} $，或比今天相比，抵消20％fainter Sun所需的能量的14％，或者大约$ \ $ \ $ \ $ 10 w m $^{ - 2} $或16％的30％flainter Sun。当暴发增加并且与此同时，CO $ _2 $浓度减少，低水平的云层增加，通过提高行星反照率来稳定气候，反之亦然。
The Sun becomes brighter with time, but Earth's climate is roughly temperate for life during its long-term history; for early Earth, this is known as the Faint Young Sun Problem (FYSP). Besides the carbonate-silicate feedback, recent researches suggest that a long-term cloud feedback may partially solve the FYSP. However, the general circulation models they used cannot resolve convection and clouds explicitly. This study re-investigates the clouds using a near-global cloud-permitting model without cumulus convection parameterization. Our results confirm that a stabilizing shortwave cloud feedback does exist, and its magnitude is $\approx$6 W m$^{-2}$ or 14% of the energy required to offset a 20% fainter Sun than today, or $\approx$10 W m$^{-2}$ or 16% for a 30% fainter Sun. When insolation increases and meanwhile CO$_2$ concentration decreases, low-level clouds increase, acting to stabilize the climate by raising planetary albedo, and vice versa.
