Abstract Numerous indicators show that multi-annual and longer oceanic baroclinic variability retains a complicated spatial structure out to decades and longer. With time-averaging, the sub-basin scales connected to abyssal topography and meteorological structures emerge in the fields. Here, using 26-years of an oceanic state estimate (ECCO), an attempt is made to extract simpler patterns from the vertical average (whole water column) annual mean temperature anomalies and, separately, the vertical structures at each horizontal position. Singular vectors (SVs)/empirical orthogonal functions (EOFs) successfully simplify vertical and horizontal fields, but principal observation patterns (POPs) do not do so. About 3 horizontal spatial patterns account for more than 95% of the interannual and longer variances. A breakdown of the purely vertical structure at each grid point leads in contrast to an intricate variability with depth. Results have implications both for future sampling strategies, and for estimates, e.g. of the accuracy of any mean oceanic scalar.

中文翻译：

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多年海洋热变化

摘要 多项指标表明，多年和更长的大洋斜压变化保持着复杂的空间结构长达数十年甚至更长时间。通过时间平均，与深海地形和气象结构相关的子流域尺度出现在现场。在这里，使用 26 年的海洋状态估计 (ECCO)，尝试从垂直平均（整个水柱）年平均温度异常以及每个水平位置的垂直结构中分别提取更简单的模式。奇异向量 (SV)/经验正交函数 (EOF) 成功地简化了垂直和水平场，但主要观测模式 (POP) 并没有这样做。大约 3 种水平空间格局占年际和更长方差的 95% 以上。每个网格点的纯粹垂直结构的分解导致与深度的复杂变化形成对比。结果对未来的采样策略和估计都有影响，例如任何平均海洋标量的准确性。