A kind of initial errors related to “spring predictability barrier” for El Niño events in Zebiak‐Cane model
A kind of initial errors related to “spring predictability barrier” for El Niño events in Zebiak‐Cane model
复制标题
DOI：
10.1029/2006gl027412
复制
发表时间：
2007-02
影响因子：
5.2
通讯作者：
M. Mu;Hui Xu;W. Duan
中科院分区：
文献类型：
--
作者：
M. Mu;Hui Xu;W. Duan
本文采用条件非线性最优摄动（CNOP）方法研究了Zebiak - Cane模型中El Niño‐南方涛动（ENSO）初始误差增长的季节依赖性。研究发现，CNOP型误差具有明显的季节依赖性，并对预测结果产生最显著的负面影响。因此，CNOPs与春季可预测性屏障（SPB）密切相关。另一方面，还发现了一些其他类型的初始误差，其模式与CNOPs不同。虽然这些初始误差的大小与所选规范的CNOPs相同，但它们要么表现出不太突出的季节依赖演变，要么对预测结果影响不大，因此不能产生El Niño事件的SPB。研究结果表明，CNOP型误差可以被认为是导致SPB的候选误差之一。如果数据同化或（和）目标观测方法具有过滤CNOP型或（和）其他类似误差的功能，则有望提高ENSO的预测能力。
Seasonal dependence of initial error growth for El Niño‐Southern Oscillation (ENSO) in Zebiak‐Cane model is investigated by using a new approach, i.e. conditional nonlinear optimal perturbation (CNOP). It is found that CNOP‐type error tends to have a significant season‐dependent evolution, and produces most considerable negative effects on the forecast results. Therefore, CNOPs are closely related to spring predictability barrier (SPB). On the other hand, some other kinds of initial errors, whose patterns are different from those of CNOPs, have also been found. Although the magnitudes of such initial errors are the same as those of CNOPs in terms of the chosen norm, they either show less prominent season‐dependent evolutions, or have trivial effect on the forecast results, and consequently do not yield SPB for El Niño events. The results of this investigation suggest that the CNOP‐type errors can be considered as one of candidate errors that cause the SPB. If data assimilation or (and) targeting observation approaches possess the function of filtering the CNOP‐type or (and) other similar errors, it is hopeful to improve the prediction skill of ENSO.