BALANCE CHARACTERISTICS OF MULTIVARIATE BACKGROUND ERROR COVARIANCE FOR TYPHOON SEASON AND ITS IMPACT ON TYPHOON DATA ASSIMILATION AND FORECAST
Building a reasonable background error covariance is the key to data assimilation.The different statistical characteristics of the multivariate background error covariance in WRFDA system for typhoon season and non-typhoon season and its impact on the analysis and forecasting of the typhoon "Fitow" (2013) are discussed.The statistical characteristics analysis indicates that compared to non-typhoon season,unbalanced velocity potential and temperature has better dynamic correlation and the correlations of relative humidity and other control variables is larger in typhoon season.Via the correlations introduced in the background error covariance,the observations can reasonably influence the analysis field in data assimilation.The cycle data assimilation and forecast results show that the new correlations built in multivariate background error covariance play an important role in the analysis and forecast of typhoon,and especially the correlations between relative humidity and other control variables obviously improve the analysis and forecast of typhoon track,intensity and precipitation.
国家科技期刊平台
NSTL
万方数据
维普
