Exploring the Pullback Attractors of a Low-Order Quasigeostrophic Ocean Model: The Deterministic Case
Exploring the Pullback Attractors of a Low-Order Quasigeostrophic Ocean Model: The Deterministic Case
复制标题
探索低阶准地转海洋模型的回拉吸引子：确定性案例
DOI：
10.1175/jcli-d-15-0848.1
复制
发表时间：
2016
影响因子：
4.9
通讯作者：
M. Chekroun
中科院分区：
文献类型：
--
作者：
S. Pierini;M. Ghil;M. Chekroun
摘要低阶准等转双环流海洋模式受到非周期强迫，这种强迫模拟了以年代际变率为主的时间依赖性。该模式被用作具有时间依赖强迫的不稳定非线性动力系统的原型，用于探索存在自然变率时气候变化的基本特征。该研究依赖于非自治动力系统及其回拉吸引子（PBAs）的理论框架，即吸引在遥远过去初始化的所有轨迹的时相关不变集。对于这种弱耗散非线性模型，严格证明了全局PBA的存在性。进行了集合模拟，并通过计算轨迹定位的概率密度函数（PDF）来评估其收敛性。对强迫振幅的敏感性分析表明，如果潜在的自治系统由小的A…
AbstractA low-order quasigeostrophic double-gyre ocean model is subjected to an aperiodic forcing that mimics time dependence dominated by interdecadal variability. This model is used as a prototype of an unstable and nonlinear dynamical system with time-dependent forcing to explore basic features of climate change in the presence of natural variability. The study relies on the theoretical framework of nonautonomous dynamical systems and of their pullback attractors (PBAs), that is, of the time-dependent invariant sets attracting all trajectories initialized in the remote past. The existence of a global PBA is rigorously demonstrated for this weakly dissipative nonlinear model. Ensemble simulations are carried out and the convergence to PBAs is assessed by computing the probability density function (PDF) of localization of the trajectories. A sensitivity analysis with respect to forcing amplitude shows that the PBAs experience large modifications if the underlying autonomous system is dominated by small-a...