确定台风强度方法的改进

Improvements to the Technique of Determining Tropical Cyclone Intensity

本文叙述了用1983—1988年GMS增强红外云图资料,对中央气象台使用的原有《用地球静止气象卫星云图估计台风强度的方法》的改进。在改进时,重点运用增强红外云图能表达云顶温度和眼区温度这一特征。在确定台风强度的云指数时,增加了下列因子:①眼区温度和直径大小;②中心强对流云区顶部的最低温度;③螺旋云带顶部的最低温度。经曲线拟合,得到云强度指数与台风中心附近最大风速的关系。改进后的方法较前更为客观、定量,对中心风力大于40m·s^(-1)的台风也可以客观地计算确定。

The Technique of Determining Tropical Cyclone Intensity in NMC is improved according to analyses of EIR imageries (1983-1988). In the determination of the cloud index for tropical cyclone intensity, some factors are incorporated, (a) the temperature and diameter of the eye area, (b) the lowest cloud-top temperature of CDO, (c) the lowest cloud -top temperature of spiral cloud band. The relationship between cloud intensity indices and maximum wind velocity near the center of tropical cyclone is also derived from curve fitting. The new technique is more objective and quantitative than anyone before.