Study On The Evaluation Of Typhoon Route Forecasting Effect And Improvement Method Of Data Assimilation

Typhoon track forecasting is the key to typhoon forecasting.Its accurate performance directly affects the overall forecast effect of typhoon and reflects the typhoon forecasting ability of a meteorological organization.Based on the forecasting effect of meteorological organizations based on typhoon track forecasting errors,this paper uses the Central Meteorological Institutions of China,the United States,Japan,and South Korea to analyze and judge the 26 typhoon track forecast error values generated in the northwestern Pacific in 2016.The analysis method uses the 24-hour,48-hour,72-hour,96-hour,and 120-hour typhoon track forecast errors as the judging factors to construct a typhoon track forecasting effect evaluation model and comprehensively evaluates the overall strength of the typhoon forecasting effect of meteorological organizations in each country.The results show that the best forecast of the typhoon route in 2016 was Japan,followed by China,the United States,and South Korea.Due to the highly non-linearity of the typhoon system and the uneven distribution of data and information,the small deviation of the initial field can cause a huge chain reaction of the entire typhoon system.Eventually,the typhoon's forecast result deviates seriously from the actual weather conditions.In order to further improve the typhoon numerical forecasting ability,considering the influence of the initial field on the typhoon track forecasting effect,using the data assimilation method to integrate the observational data and numerical model into the mathematical theory to obtain an analytical field with less theoretical error,and thus a typhoon forecasting model Provide a more accurate initial field of forecast to achieve the purpose of enhancing typhoon forecasting capabilities.The four-dimensional variation and ensemble Kalman filtering in data assimilation are summarized and the algorithm derivation is described in detail.Through numerical experiments,the assimilation performances of the two methods are compared to determine whether the method can reduce typhoon path forecast error.Enhance the effect of typhoon forecast results.The results show that although the four-dimensional variational assimilation can promote the typhoon forecasting effect,the ensemble Kalman filter assimilation method is more adaptable to the complicated and varied environmental conditions in the atmosphere.The assimilation results are good and stable,and can be typhoon.The forecast model provides a more realistic and effective initial field,and aims to improve the typhoon track forecasting effect.