Variations in ocean bottom pressure are important for understanding ocean circulation and climate. While most studies have focused on atmospherically driven variability, here we use eddy-permitting large ensemble simulation output from the OceaniC Chaos–ImPacts, strUcture, predicTability (OCCIPUT) project to isolate chaotic intrinsic variability generated by nonlinear oceanic processes. Analyzing separately the mean seasonal cycle and remainder variability in intra-annual (60–365 days) and subseasonal (2–60 days) bands, we find intrinsic variations larger than atmospherically driven ones over eddy-active regions across all timescales, particularly in the intra-annual range, where intrinsic variations dominate in almost 25% of the oceans. At scales larger than mesoscale, intrinsic variability is still considerable, supporting the process of energy inverse cascade toward lower frequency and larger scales. Results highlight the importance of intrinsic variability over a range of spatiotemporal scales and provide new insights on the interpretation of GRACE-like observations and their de-aliasing procedures.

中文翻译：

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海洋混沌内在变化对底部压力的影响以及对数据和模型分析的影响

海底压力的变化对于了解海洋环流和气候很重要。虽然大多数研究都集中在大气驱动的变异性上，但在这里我们使用来自 OceaniC Chaos–ImPacts、structure、predictability (OCCIPUT) 项目的允许涡流的大型集合模拟输出来隔离非线性海洋过程产生的混沌内在变异性。分别分析年内（60-365 天）和次季节（2-60 天）波段的平均季节周期和剩余变化，我们发现在所有时间尺度上，涡流活跃区域的内在变化大于大气驱动的变化，特别是在年内范围，其中内在变化在近 25% 的海洋中占主导地位。在大于中尺度的尺度上，内在变异性仍然相当大，支持能量逆级联向低频和更大尺度的过程。结果突出了在一系列时空尺度上内在可变性的重要性，并为解释类似 GRACE 的观测及其消除混叠程序提供了新的见解。