物理学报2012，Vol.61Issue(11)：556-564,9.
外强迫对Lorenz系统初值可预报性的影响
Influence of external forcing on the predictability of Lorenz model
摘要
Abstract
The influence of external forcing on chaotic character,Lorenz map structure and the predictability is studied with the Lorenz system which has a forcing term,and the atmospheric predictability forced by sea surface temperature（SST） is also analyzed.The chaotic attractors are related to the forcing term that changes the moving rules of system and makes randomicity of attractors reduce. The probability distribution function of Lorenz system in the x-y plane has a bimodal structure with two clearly separated peaks.In the absence of forcing,both peaks are equally likely.When an external forcing introduced,the probability of state moving around two Lorenz attractors is changed,and it makes the two peaks asymmetric.It is found that the single cusp of Lorenz map obtained in the absence of forcing splits into two cusps that represent two branches of the Lorenz attractor when the forcing is introduced.On Lorenz map,the moving directions of two cusps and the difference between two cusps and single cusp are determined by the sign and the magnitude of forcing term.The predictability of Lorenz system is also deeply affected by external forcing.The predictability is increased by introducing forcing,and especially the range of increasing is larger when the absolute value of forcing term is bigger. It is also found that the higher potential predictability is obtained by forcing with the stronger SST which causes the larger external variance.关键词
Lorenz系统/外强迫/Lorenz映射/可预报性Key words
Lorenz system/external forcing/Lorenz map/predictability分类
数理科学引用本文复制引用
黎爱兵,张立凤,项杰..外强迫对Lorenz系统初值可预报性的影响[J].物理学报,2012,61(11):556-564,9.基金项目
国家自然科学基金（批准号：40975031）资助的课题. （）
