首页>
中文期刊>
《大气科学进展:英文版》
>Is Model Parameter Error Related to a Significant Spring Predictability Barrier for El Nio events? Results from a Theoretical Model
Is Model Parameter Error Related to a Significant Spring Predictability Barrier for El Nio events? Results from a Theoretical Model
Within a theoretical ENSO model, the authors investigated whether or not the errors superimposed on model parameters could cause a significant "spring predictability barrier" (SPB) for El Nio events. First, sensitivity experiments were respectively performed to the air-sea coupling parameter, α and the thermocline effect coefficient μ. The results showed that the uncertainties superimposed on each of the two parameters did not exhibit an obvious season-dependent evolution; furthermore, the uncertainties caused a very small prediction error and consequently failed to yield a significant SPB. Subsequently, the conditional nonlinear optimal perturbation (CNOP) approach was used to study the effect of the optimal mode (CNOP-P) of the uncertainties of the two parameters on the SPB and to demonstrate that the CNOP-P errors neither presented a unified season-dependent evolution for different El Nio events nor caused a large prediction error, and therefore did not cause a significant SPB. The parameter errors played only a trivial role in yielding a significant SPB. To further validate this conclusion, the authors investigated the effect of the optimal combined mode (i.e. CNOP error) of initial and model errors on SPB. The results illustrated that the CNOP errors tended to have a significant season-dependent evolution, with the largest error growth rate in the spring, and yielded a large prediction error, inducing a significant SPB. The inference, therefore, is that initial errors, rather than model parameter errors, may be the dominant source of uncertainties that cause a significant SPB for El Nio events. These results indicate that the ability to forecast ENSO could be greatly increased by improving the initialization of the forecast model.
展开▼
机译:在切尔诺贝利事故发生后,在波希米亚中部的一个地方,将Cs-137从空气转移到作物,牛奶,牛肉和人体的模型。 pRYma T1型号的测试。 (model de la transferencia de Cs-137 desde el aire a las cosechas,la leche,la carne de vacuno y el cuerpo humano producido por el accidente de Chernobyl,en una localizacion en la Bohemia Central.Test del modelo pRYma T1)