A Medium/Long-Range Forecast of Pacific Subtropical High Based on Dynamic Statistic Model Reconstruction
Mei Hong, Zhang Ren, Kefeng Liu, YU Dan-dan · Kishocho Kenkyu Jiho/Kishocho kenkyu jiho · 2007
Based on the 500-hPa geopotential height eld series of T106 numerical forecast products, by empirical orthogonal function (EOF) time-space separation, and on the hypotheses of EOF space-models being stable, the EOF time coecien t series were taken as dynamical statistic model variables. The dynamic system reconstruction idea and genetic algorithm were introduced to make the dynamical model parameters optimized, and a nonlinear dynamic statistic model of EOF separating time coecien t series was established. By the model time integral and EOF time-space reconstruction, a medium/long-range forecast of subtropical high was carried out. The results show that the dynamical model forecast and T106 numerical forecast were approximately similar in the short-range forecast (65 days), but in the medium/long-range forecast (>5 days), the forecast results of dynamical model was superior to that of T106 numerical products. A new method and idea were presented for diagnosing and forecasting complicated weathers such as subtropical high, and showed a better application outlook.