Accounting for Changing Temperature Patterns Increases Historical Estimates of Climate Sensitivity
Accounting for Changing Temperature Patterns Increases Historical Estimates of Climate Sensitivity
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DOI：
10.1029/2018gl078887
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发表时间：
2018-08-28
影响因子：
5.2
通讯作者：
Titchner, Holly
中科院分区：
文献类型：
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作者：
Andrews, Timothy;Gregory, Jonathan M.;Titchner, Holly
利用大气模式比较项目II数据集，利用观测到的历史（1871-2010）月海面温度和海冰变化强迫8个大气环流模式（AGCMs）。因此，agcm具有与观测到的历史气候变化相似的温度模式和趋势。agcm模拟了气候反馈的扩散，类似于对二氧化碳翻了两番的响应的耦合模拟。然而，反馈更加稳定，有效气候敏感性（EffCS）更小。这是由于一种模式效应，即观测到的历史海面温度变化的模式产生了更多的负云和长波晴空反馈。假设模式模拟的长期温度变化模式及其辐射响应是可信的；这意味着，历史能源收支变化对EffCS的现有限制给出了过低和过度限制的值，特别是在上限。例如，模式效应使Otto等（2013）的长期EffCS中位数和5-95%置信区间从1.9K （0.9-5.0K）增加到3.2K （1.5-8.1K）。
Eight atmospheric general circulation models (AGCMs) are forced with observed historical (1871-2010) monthly sea surface temperature and sea ice variations using the Atmospheric Model Intercomparison Project II data set. The AGCMs therefore have a similar temperature pattern and trend to that of observed historical climate change. The AGCMs simulate a spread in climate feedback similar to that seen in coupled simulations of the response to CO2 quadrupling. However, the feedbacks are robustly more stabilizing and the effective climate sensitivity (EffCS) smaller. This is due to a pattern effect, whereby the pattern of observed historical sea surface temperature change gives rise to more negative cloud and longwave clear-sky feedbacks. Assuming the patterns of long-term temperature change simulated by models, and the radiative response to them, are credible; this implies that existing constraints on EffCS from historical energy budget variations give values that are too low and overly constrained, particularly at the upper end. For example, the pattern effect increases the long-term Otto et al. (2013, ) EffCS median and 5-95% confidence interval from 1.9K (0.9-5.0K) to 3.2K (1.5-8.1K).