Coupled climate response to Atlantic Multidecadal Variability in a multi-model multi-resolution ensemble
Coupled climate response to Atlantic Multidecadal Variability in a multi-model multi-resolution ensemble
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DOI：
10.1007/s00382-022-06157-9
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发表时间：
2022-02-07
期刊：
影响因子：
4.6
通讯作者：
Senan, Retish
中科院分区：
文献类型：
--
作者：
Hodson, Daniel L. R.;Bretonniere, Pierre-Antoine;Senan, Retish
北大西洋海表温度（SST）在二十世纪和世纪初经历了明显的多年变化。我们研究了这种大西洋的年代际变率（AMV），也被称为大西洋的年代际振荡（AMO），在低和高空间分辨率的五个耦合气候模式的合奏气候的影响。我们使用耦合模式相互比较项目的十年期气候预测项目C组件（CMIP 6 DCPP-C）指定的SST轻推方案，在耦合模式模拟中对北大西洋的AMV施加持续的正/负相位; SST可以自由地在该区域之外演变。大规模的季节平均响应积极的AMV涉及欧亚大陆和美洲的广泛变暖，太平洋的冷却模式类似于太平洋年代际振荡（PDO），以及热带辐合带（ITCZ）的北移。伴随的全球大气环流的变化导致降水量的广泛变化。我们使用方差分析（ANOVA）来证明，这种大规模的气候响应是伴随着显着的差异模型之间的共同AMV强迫，特别是在热带地区。这些差异可能是由于模式之间北大西洋海气热通量的变化造成的，尽管北大西洋SST强迫模式是共同的。我们不能检测到一个广泛的影响，增加模式的水平分辨率在这种气候响应，与ITCZ，进一步向北移动的正相的AMV在更高的分辨率配置的例外。
North Atlantic sea surface temperatures (SSTs) underwent pronounced multidecadal variability during the twentieth and early twenty-first century. We examine the impacts of this Atlantic Multidecadal Variability (AMV), also referred to as the Atlantic Multidecadal Oscillation (AMO), on climate in an ensemble of five coupled climate models at both low and high spatial resolution. We use a SST nudging scheme specified by the Coupled Model Intercomparision Project's Decadal Climate Prediction Project Component C (CMIP6 DCPP-C) to impose a persistent positive/negative phase of the AMV in the North Atlantic in coupled model simulations; SSTs are free to evolve outside this region. The large-scale seasonal mean response to the positive AMV involves widespread warming over Eurasia and the Americas, with a pattern of cooling over the Pacific Ocean similar to the Pacific Decadal Oscillation (PDO), together with a northward displacement of the inter-tropical convergence zone (ITCZ). The accompanying changes in global atmospheric circulation lead to widespread changes in precipitation. We use Analysis of Variance (ANOVA) to demonstrate that this large-scale climate response is accompanied by significant differences between models in how they respond to the common AMV forcing, particularly in the tropics. These differences may arise from variations in North Atlantic air-sea heat fluxes between models despite a common North Atlantic SST forcing pattern. We cannot detect a widespread effect of increased model horizontal resolution in this climate response, with the exception of the ITCZ, which shifts further northwards in the positive phase of the AMV in the higher resolution configurations.