Research On Predictability Of Initial Field Based On FVCOM

The uncertainty of the initial field of the ocean numerical model leads to different development states of the error,which plays an important role in regulating the forecasting ability of the model.Only by fully understanding the law of error growth,can the predictability of the model be known,and then the predictability of the model can be improved.The predictability of using different ocean models to build ocean models with different resolutions is different.Previous studies have not been sufficient,and no general conclusion has been formed.The research on the law of error growth in China’s offshore waters is very important.In order to discuss the law of error growth in the high-resolution Bo and Yellow Sea models,qualitative conclusions are given.In this paper,a high-resolution 3D ocean model covering the Bohai and Yellow Seas is established based on the unstructured triangular mesh structure,finite volume,free surface,and 3D primitive equation ocean numerical model FVCOM.In the study of the law of error growth of uncertainty,the accuracy of SST forecast is an important criterion for the ability of ocean forecasting.Therefore,this paper takes the evolution law of SST error as the research object to discuss the first type of predictability of the model.Aiming at the evolution law of SST errors of the high-resolution 3D ocean models of the Bohai and Yellow Seas established by the FVCOM model,two methods are used in this paper:Monte Carlo method and growth model propagation method(BGM).The Monte Carlo method generates an initial temperature disturbance in the form of white noise in all sea areas.The initial error of the model’s SST in shallow water areas such as the Bohai Sea and the Yellow Sea is quickly dissipated.The error at the boundary has an increasing trend.The BGM method generates the initial temperature disturbance with a clear error shape.The initial error in the Bohai Sea area is rapidly dissipated,the initial error in the open boundary area has a decreasing trend,and the initial error in the Yellow Sea area has an obvious increasing trend.The initial error pattern of,has a tendency to spread to the week.For the SST regional error evolution law of the high-resolution 3D ocean models of the Bohai and Yellow Seas established by the FVCOM model,the Monte Carlo method and the BGM method are also used in this paper.The Monte Carlo method and the BGM method generate initial temperature disturbances in each sea area respectively.The initial disturbance in each sea area will cause errors in all sea areas,and these errors will further increase or decrease.These experimental results show that the initial field uncertainty of SST will quickly dissipate in most areas of the Bohai and Yellow Seas,the model is stable,and has good firstclass predictability,but the uncertainty at the open boundary will increase,indicating that this The predictability of the first type at is poor;the initial error in the model,whether it is a noiselike error or an error with a specific distribution shape,converges to a specific shape,indicating that the SST error distribution shape is stable,and the source of uncertainty in the initial field Concentrated in specific areas and morphologically stable.