Spatial Patterns of Modeled Climate Feedback and Contributions to Temperature Response and Polar Amplification
Spatial Patterns of Modeled Climate Feedback and Contributions to Temperature Response and Polar Amplification
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DOI：
10.1175/2011jcli3863.1
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发表时间：
2011-07-01
影响因子：
4.9
通讯作者：
Stuber, Nicola
中科院分区：
文献类型：
--
作者：
Crook, Julia A.;Forster, Piers M.;Stuber, Nicola
由8个大气环流模式产生的局地气候反馈和平衡局地温度响应的空间型是由二氧化碳(CO2)加倍强迫的板条海洋产生的。利用英国气象局哈德利中心板块海洋气候模式第3版(HadSM3)，分析扩展到了其他强迫机制。与以前的研究一致，模式间的最大差异在于热带云的反馈。然而，平衡温度响应中最大的模式间扩散来自水汽加消失率反馈，而不是云，这与以前的研究不一致。虽然地面反照率反馈在年平均中对高纬度变暖的贡献最大，但与热带地区(极地放大)相比，其影响显著地被短波云反馈所改善。在不同季节，贡献的相对重要性有很大差异，在极地放大最大的冬秋季，长波云天反馈和水平热量输送加上海洋热量释放起主要作用。年平均极地放大的最大模式间扩散是由于水平热量输送和短波云反馈的变化所致。2 x CO2、+2%太阳、低层散射气溶胶和高层吸收气溶胶强迫下的HadSM3局地气候反馈的空间分布模式比2 x CO2强迫下的更相似。然而，与其他强迫机制相比，对高吸收气溶胶的平衡温度响应显示出显著增强的极地放大，这主要是由于水平热输送和水汽加衰减率反馈的差异，强迫本身起到了减小放大作用的作用。模式和强迫机制之间高纬度响应的这种差异，使得人们很难推断最近北极温度变化的具体原因。
Spatial patterns of local climate feedback and equilibrium partial temperature responses are produced from eight general circulation models with slab oceans forced by doubling carbon dioxide (CO2). The analysis is extended to other forcing mechanisms with the Met Office Hadley Centre slab ocean climate model version 3 (HadSM3). In agreement with previous studies, the greatest intermodel differences are in the tropical cloud feedbacks. However, the greatest intermodel spread in the equilibrium temperature response comes from the water vapor plus lapse rate feedback, not clouds, disagreeing with a previous study. Although the surface albedo feedback contributes most in the annual mean to the greater warming of high latitudes, compared to the tropics (polar amplification), its effect is significantly ameliorated by shortwave cloud feedback. In different seasons the relative importance of the contributions varies considerably, with longwave cloudy-sky feedback and horizontal heat transport plus ocean heat release playing a major role during winter and autumn when polar amplification is greatest. The greatest intermodel spread in annual mean polar amplification is due to variations in horizontal heat transport and shortwave cloud feedback. Spatial patterns of local climate feedback for HadSM3 forced with 2 x CO2, +2% solar, low-level scattering aerosol and high-level absorbing aerosol are more similar than those for different models forced with 2 x CO2. However, the equilibrium temperature response to high-level absorbing aerosol shows considerably enhanced polar amplification compared to the other forcing mechanisms, largely due to differences in horizontal heat transport and water vapor plus lapse rate feedback, with the forcing itself acting to reduce amplification. Such variations in high-latitude response between models and forcing mechanisms make it difficult to infer specific causes of recent Arctic temperature change.