针对QuikSCAT散射计风场资料对台风级别的强风速区还无法准确刻画这个技术问题,引入台风移速、移向、摩擦等客观因素对该风场产品资料进行非对称加强订正;然后利用四维同化技术,并设计了先同化后预报两个阶段的试验方案,对“云娜”台风进行了数值模拟试验。试验结果表明:通过模式约束调整,四维同化技术可以把QuikSCAT海面风场资料引入到整层模式大气中,并对整层风场和气压场的强度及路径模拟都有很大的改进,而且该资料还提高了预报阶段台风强度的模拟效果,并对登陆点的预报起到了积极作用。
Aiming at a technological problem that the wind data of QuikSCAT scatterometer cannot accurately describe the zone of typhoon-level strong wind speed, this paper introduces some objective factors such as the typhoon moving speed, direction and friction when constructing the asymmetric strengthening of the QuikSCAT wind field. Then by adopting four-dimensional data assimilation technology, the experiment including assimilation and forecasting phases is designed to simulate Typhoon Rananim numerically. The results show that, by using the four-dimensional data assimilation technology, QuikSCAT wind data which can be introduced to the whole-column model atmosphere and with constraints and adjustment of the model, improves greatly the simulating effects of the whole-column wind, pressure field and the track, in addition to the simulated typhoon intensity during forecast and works positively for the forecasting of landfall sites.