Some implications of a new approach to the water vapour feedback
Some implications of a new approach to the water vapour feedback
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水蒸气反馈新方法的一些影响
DOI：
10.1007/s00382-012-1456-3
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发表时间：
2012
期刊：
影响因子：
4.6
通讯作者：
Ingram W
中科院分区：
文献类型：
--
作者：
Ingram W
水汽反馈是最大的物理气候反馈。它还对大气环流模式（GCM）中气候敏感性的不确定性范围做出了第二大贡献。要追溯这些差异的物理原因，以期限制气候敏感性，就需要进行适当的量化。然而，政府间气候变化专门委员会认为，“水蒸气反馈”和“递减率反馈”的传统诊断几乎不能深入了解GCM气候敏感性之间的差异。我们表明，传统诊断的水汽反馈实际上在形式上对调查GCM的气候敏感性之间的差异是无用的-传统的“水汽反馈”和“直减率反馈”之间的关系使得“水汽反馈”和它们的总和之间的相关性无关紧要：也就是说，从统计学上讲，了解这种“反馈”使人们无法对总和以及气候敏感性得出任何结论。这主要是因为在大气环流模式中，相对湿度随气候变化的变化很小。一个更详细的物理分析得出的结论是，在大气环流模式中看到的相对湿度在变暖时的总体平均下降是有坚实的物理基础的。这一点和其他物理论点表明，“水蒸气反馈”越强，气候的敏感性就越低。基于水蒸气反馈的“部分泊松”模型的诊断避免了这些问题。根据水蒸气反馈的传统观点，对当今气候变化的天真推断表明，我们地球的部分地区接近当地达到的条件，一旦它们足够广泛，就会允许水蒸气温室效应失控。当然，这在地质历史上从未发生过，在类似地球的GCM中也没有看到。再一次，“部分爱因斯坦”的方法提供了一个简单的定性解释，通过表明水蒸气反馈只能抵消部分基本普朗克定律的负反馈。
The water vapour feedback is the largest physical climate feedback. It also gives the second-largest contribution to the range of uncertainty in climate sensitivity in General Circulation Models (GCMs). Tracing these differences back to their physical causes in the hope of constraining climate sensitivity requires an appropriate quantification. Yet the Intergovernmental Panel on Climate Change judge that the conventional diagnosis of a “water vapour feedback” and a “lapse rate feedback” provides little insight into differences between GCMs’ climate sensitivities. We show that the conventionally diagnosed water vapour feedback is in fact formally useless for investigating differences between GCMs’ climate sensitivities—the anticorrelation between conventional “water vapour feedback” and “lapse rate feedback” makes the correlation between the “water vapour feedback” and their sum insignificant: i.e. statistically, knowing this “feedback” allows one to conclude nothing about the sum and thence about climate sensitivity. This follows primarily from how little relative humidity (RH) changes with climate change in GCMs. A more detailed physical analysis concludes that the overall mean decrease of RH on warming seen in GCMs is robustly physically based. This and other physical arguments then suggest that the stronger the positive “water vapour feedback”, the less sensitive climate can be expected to be. A diagnosis based on the “partly-Simpsonian” model of water vapour feedback avoids these problems. On the conventional view of the water vapour feedback, naive extrapolation of variations within present-day climate suggests that parts of our planet are close to locally reaching conditions that would allow a run-away water vapour greenhouse effect once they were extensive enough. Of course this has never occurred in geological history, and is not seen in Earth-like GCMs. Again, the “partly-Simpsonian” approach provides a simple qualitative explanation, by showing that the water vapour feedback can only cancel part of the basic Planck’s Law negative feedback.
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影响因子：
--
作者：
B. Soden;F. Bretherton
通讯作者：
B. Soden;F. Bretherton
气候变化的水蒸气反馈的一个非常简单的模型
影响因子：
8.9
作者：
Ingram W
通讯作者：
Ingram W
影响因子：
7.5
作者：
J. Houghton;Y. Ding;D. Griggs;M. Noguer;P. Linden;X. Dai;K. Maskell;C. Johnson
通讯作者：
J. Houghton;Y. Ding;D. Griggs;M. Noguer;P. Linden;X. Dai;K. Maskell;C. Johnson
小型 GCM 系统中的水蒸气反馈：两种方法
DOI：
10.1029/2011jd017221
发表时间：
2012
期刊：
Atmospheres
影响因子：
--
作者：
Ingram W
通讯作者：
Ingram W
DOI：
--
发表时间：
1998
期刊：
影响因子：
--
作者：
R. Schudlich;J. Price
通讯作者：
J. Price