Effects of specifying bottom boundary conditions in an ensemble of atmospheric GCM simulations
Effects of specifying bottom boundary conditions in an ensemble of atmospheric GCM simulations
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大气 GCM 模拟集合中指定底部边界条件的影响
DOI：
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发表时间：
2000
期刊：
影响因子：
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通讯作者：
J. Sheng
中科院分区：
文献类型：
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作者：
F. Zwiers;Xiaolan L. Wang;J. Sheng
对 6 个 47 年气候模拟集合的年际变化进行了分析，其中指定了随时间变化的海面温度 (SST) 和海冰范围。将变异性与气候海温和海冰范围的 250 年控制模拟进行比较。模拟是使用加拿大气候中心第二代大气环流模型进行的。方差分析方法与旋转经验正交函数分析相结合，评估规定边界条件对模拟大气环流结构和变化的影响，并识别潜在的可预测的空间相干变化模式。分析的量是季节性平均 500 hPa 位势 (Z500) 和平均海平面压力 (Pmsl)。规定的边界条件增加了模拟大气的可变性并调节其大尺度环流结构。发现 DJF 和 MAM 对 Z500 的影响最强，SON 的影响最弱。规定的边界条件在厄尔尼诺-南方涛动（ENSO）年对温带陆地区域，尤其是北美北部地区有显着影响，但在非ENSO年影响不大。几种主要空间模式的可变性受到规定边界条件的显着影响。与之前的一些研究相比，我们发现模拟的北大西洋涛动不受规定的边界强迫的影响。
Interannual variability in an ensemble of six 47-year climate simulations with specified time-varying sea surface temperature (SST) and sea ice extent is analyzed. Variability is compared with that in a 250-year control simulation with climatological SST and sea ice extent. The simulations were performed with the Canadian Climate Centre second generation General Circulation Model. An analysis of variance approach was combined with rotated Empirical Orthogonal Function analysis to assess the influence of the prescribed boundary conditions on the simulated atmospheric circulation structure and variability and to identify potentially predictable spatially coherent modes of variation. The quantities analyzed are seasonal mean 500 hPa geopotential (Z500) and mean sea level pressure (Pmsl). The prescribed boundary conditions increase the variability of the simulated atmosphere and modulate its large-scale circulation structure. The effects on Z500 are found to be strongest in DJF and MAM and weakest in SON. The prescribed boundary conditions have a significant effect over the extratropical land areas, especially over northern North America, in El Nino-Southern Oscillation (ENSO) years, but have little influence in non-ENSO years. The variability of several of the leading spatial modes is significantly affected by the prescribed boundary conditions. In contrast with some previous studies, we find that the simulated North Atlantic Oscillation is not affected by the prescribed boundary forcing.