Drawing on a 50-member ocean ensemble hindcast, the magnitude and characteristic temporal and spatial scales of intrinsic and forced sea surface height (SSH) variability are evaluated over a 37-year period. The intrinsic and forced contributions derived from the ensemble are found to have similar temporal spectra, but different characteristic spatial scales. These results suggest that, with an appropriate choice of cutoff scales, simple spatial filtering can be used to estimate the forced and intrinsic contributions given either a single model run, or an observational data set. The method is tested using a single member drawn from the ensemble, before being applied to the observed altimetric record. Two sample applications with relevance to large-scale climate are used to illustrate the method's potential utility. Firstly, the long-term trends calculated from the total and recreated forced components using the altimetric record are compared and local differences highlighted. Second, the recreated forced SSH is shown to covary with the North Atlantic Oscillation at seasonal time scales in regions where no such influence can be found using the original SSH signal. Some limitations and uses for which the method may prove unsuitable are also briefly considered.

中文翻译：

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一种估算应用于高度观测的海面高度变化的内在和大气强迫贡献的方法

利用 50 个成员的海洋集合后报，评估了 37 年期间内在和强迫海面高度 (SSH) 变化的幅度和特征时空尺度。发现来自集合的内在和强制贡献具有相似的时间谱，但具有不同的特征空间尺度。These results suggest that, with an appropriate choice of cutoff scales, simple spatial filtering can be used to estimate the forced and intrinsic contributions given either a single model run, or an observational data set. 该方法使用从集合中抽取的单个成员进行测试，然后再应用于观察到的高度记录。两个与大尺度气候相关的示例应用被用来说明该方法的潜在效用。首先，比较使用高度记录从总和重新创建的受迫分量计算出的长期趋势，并突出显示局部差异。其次，在使用原始 SSH 信号无法发现这种影响的地区，重建的强迫 SSH 在季节性时间尺度上与北大西洋涛动发生共变。还简要考虑了该方法可能不适合的一些限制和用途。