Ensemble forecasting of tropical cyclone (TC) motion was studied using a primitive equation barotropic model by perturbing initial position and structure for 1979 1993 TC. The results show that TC initial position per...Ensemble forecasting of tropical cyclone (TC) motion was studied using a primitive equation barotropic model by perturbing initial position and structure for 1979 1993 TC. The results show that TC initial position perturbation affects its track, but the ensemble mean is close to control forecast. Experiments was also performed by perturbing TC initial parameters which were used to generate TC initial field, and more improvement can be obtained by taking ensemble mean of selective member than selecting members randomly. The skill of 60 % 70 % of all cases is improved in selective ensemble mean. When the ambient steering current is weak, more improvement can be obtained over the control forecast.展开更多
The impact of axiasymmetric structure of tropical cyclone, beta effect and the environmentalflow field on tropical cyclone motion have been investigated in terms of theoretical analysisand numerical modelling. The sud...The impact of axiasymmetric structure of tropical cyclone, beta effect and the environmentalflow field on tropical cyclone motion have been investigated in terms of theoretical analysisand numerical modelling. The sudden change of tropical cyclone (TC) motion has also beenstudied. The analysis and modelling results indicate that the impact of axiasymmetric struc-ture of TC on its motion cannot be underestimated in the certain stage of TC development.Under the specified conditions, it may lead to snakelike or loop motion of TC. The movingdirection and speed of TC will change suddenly when the interaction of environmental flowfield, beta effect and axiasymmetric wind and pressure fields reach a critical state.展开更多
A barotropic prirnitive equation model is used to simulate the tropical cyclone motion.Tropical cyclone movements under different environmental flow backgrounds were examined and sensitivity of tropical cyclone tracks...A barotropic prirnitive equation model is used to simulate the tropical cyclone motion.Tropical cyclone movements under different environmental flow backgrounds were examined and sensitivity of tropical cyclone tracks were discussed.Conclusions of practical significance have been obtained in this paper.展开更多
文摘Ensemble forecasting of tropical cyclone (TC) motion was studied using a primitive equation barotropic model by perturbing initial position and structure for 1979 1993 TC. The results show that TC initial position perturbation affects its track, but the ensemble mean is close to control forecast. Experiments was also performed by perturbing TC initial parameters which were used to generate TC initial field, and more improvement can be obtained by taking ensemble mean of selective member than selecting members randomly. The skill of 60 % 70 % of all cases is improved in selective ensemble mean. When the ambient steering current is weak, more improvement can be obtained over the control forecast.
文摘The impact of axiasymmetric structure of tropical cyclone, beta effect and the environmentalflow field on tropical cyclone motion have been investigated in terms of theoretical analysisand numerical modelling. The sudden change of tropical cyclone (TC) motion has also beenstudied. The analysis and modelling results indicate that the impact of axiasymmetric struc-ture of TC on its motion cannot be underestimated in the certain stage of TC development.Under the specified conditions, it may lead to snakelike or loop motion of TC. The movingdirection and speed of TC will change suddenly when the interaction of environmental flowfield, beta effect and axiasymmetric wind and pressure fields reach a critical state.
文摘A barotropic prirnitive equation model is used to simulate the tropical cyclone motion.Tropical cyclone movements under different environmental flow backgrounds were examined and sensitivity of tropical cyclone tracks were discussed.Conclusions of practical significance have been obtained in this paper.
