On the predictability limit of convection models of the Earth's mantle
On the predictability limit of convection models of the Earth's mantle
复制标题
论地幔对流模型的可预测极限
DOI：
10.1002/2014gc005254
复制
发表时间：
2014
期刊：
影响因子：
3.7
通讯作者：
P. Tackley
中科院分区：
文献类型：
--
作者：
L. Bello;N. Coltice;T. Rolf;P. Tackley
重建地球地幔中的对流是从地震学到沉积学等多种学科的关键问题。这些基于地球动力学模型的重建方法的共同和根本的局限性是初始条件未知。由于地幔对流的混沌性质，初始条件的误差随着时间的推移呈指数增长，并限制了预测和后报能力。在这项工作中，我们估计的第一次地球的地幔对流的可预测性的限制。根据孪生实验方法，我们计算了李雅普诺夫时间（即，e-折叠时间），用于最先进的3-D球形对流模型，变化的流变学和瑞利数。我们最接近地球的乐观解给出的李雅普诺夫时间为1.36 ± 1.3亿年。在最佳初始条件下，不确定性的粗略估计约为5%，导致地幔对流的可预测性极限为9500万年。我们的研究结果表明，错误的增长可能会产生不切实际的对流结构在时间尺度短于泛大陆扩散。
Reconstructing convective flow in the Earth's mantle is a crucial issue for a diversity of disciplines, from seismology to sedimentology. The common and fundamental limitation of these reconstructions based on geodynamic modeling is the unknown initial conditions. Because of the chaotic nature of convection in the Earth's mantle, errors in initial conditions grow exponentially with time and limit forecasting and hindcasting abilities. In this work, we estimate for the first time the limit of predictability of Earth's mantle convection. Following the twin experiment method, we compute the Lyapunov time (i.e., e‐folding time) for state of the art 3‐D spherical convection models, varying rheology, and Rayleigh number. Our most Earth‐like and optimistic solution gives a Lyapunov time of 136 ± 13 Myr. Rough estimates of the uncertainties in best guessed initial conditions are around 5%, leading to a limit of predictability for mantle convection of 95 Myr. Our results suggest that error growth could produce unrealistic convective structures over time scales shorter than that of Pangea dispersal.
影响因子：
5.3
作者：
Davies, D. Rhodri;Goes, S.;Ritsema, J.
通讯作者：
Ritsema, J.