2012年台风“天秤”强度变化及对海表温度的影响

The Intensity Change of Typhoon “Tembin” (2012) and Its Impact on Sea Surface Temperature

2012年强台风“天秤”的强度出现了“三起三落”的变化。在此过程中,既有高海温、弱垂直切变、强水汽辐合和强降水等有利于台风增强的因素作用,也有低海温、强垂直切变、弱水汽辐合和弱降水、陆地影响等抑制台风强度的因素发生;台风强度变化则依赖其中的主导因素。同时,另一个台风“布拉万”对水汽的争夺也影响了“天秤”强度。分析表明:环境风垂直切变大小的变化总是超前(6~12小时)于台风强度的改变,因此它对台风的强弱有一定的预示作用;当“天秤”缓慢移动时候,其路径后产生了海表温度显著下降的现象。

Typhoon “Tembin” (2012) had a protean intensity change. By using multiple observational data, the preliminary factors are identified which have influence on the typhoon intensity changes. And typhoon’s impact on the sea surface temperature (SST) is also analyzed. During the intensity change stages, the intensifications of typhoon were associated with the high sea surface temperature, weak vertical shear, strong moisture convergence and heavy rainfall. In contrast, the depressions of typhoon were associated with the low sea surface temperature, strong vertical shear, weak moisture convergence, heavy rainfall and drag effect by Taiwan Island. Besides, the vicinal typhoon “Bolaven” absorbed the mass of water vapor from “Tembin”, which in turn weakened the Typhoon Tembin. Furthermore, the change of environmental vertical wind shear is always leading to the change of typhoon’s intensity, so it may be a precursor of typhoon’s intensity change. Finally, there was significant SST cooling on the track after Tembin’s passage, especially when its moving speed was very slow.