模式参数的不确定性对日本南部黑潮大弯曲路径预报的影响

基于1.5层浅水方程模式,利用条件非线性最优参数扰动(CNOP-P)方法,研究模式参数的不确定性对黑潮大弯曲路径预报的影响。研究表明,单个模式参数误差如侧向摩擦系数误差、界面摩擦系数误差以及在不同季节具有不同约束的风应力大小误差,对黑潮大弯曲路径预报的影响较小,并且对背景流场的选取具有一定的敏感性;所有模式参数误差同时存在时对黑潮大弯曲路径预报具有一定的影响,并且预报结果在9个月左右不能被接受。因此,要提高黑潮大弯曲路径的预报技巧,模式中的参数需要给出更好的估计。

The impact of the model parameter uncertainties on the predictability of the Kuroshio large meander path south of Japan

Based on a 1.5-layer shallow-water model, the impact of model parameter errors on the prediction of the Kuroshio large meander (LM) path in south of Japan was investigated by the conditional nonlinear optimal parameter perturbation (CNOP-P) method. The results showed that the impacts of the single model parameter errors such as the lateral friction coefficient, interfacial friction coefficient and the amplitude of wind stress with different constraints in different seasons, on the prediction of the Kuroshio LM path were relatively small. In addition, they were sensitive to the background field, which was the Kuroshio transition state from non-large meander (NLM) path to LM path. However, the optimal error mode of all the model parameter errors existing simultaneously had a large impact on the prediction of the Kuroshio LM path and the results of prediction could not be accepted. Therefore, in order to enhance the forecast skill of the Kuroshio LM path in this model, the model parameters should give the best possible estimates.