海面温度变化影响台风"海棠"强度的数值研究

通过对台风"海棠"5 d的数值模拟,研究海表温度(SST)变化对台风强度的影响。与NCEP月平均海表温度相对比,在中尺度大气模式中引入热带测雨卫星(TRMM)微波成像仪(TMI)/先进微波扫描辐射计(AMSR-E)来考察SST对台风"海棠"路径和强度的影响。研究结果表明,每天变化SST的试验模拟的台风强度和路径整体效果不错;模拟的台风路径不敏感于SST的变化,而台风强度的变化不仅取决于由于台风移动引发的SST冷却的幅度大小,而且取决于SST冷却区域的相对位置。在台风"海棠"强烈发展过程中,台风中心右侧冷却区对台风中心气压影响很小;台风强烈发展过后,SST冷却区开始影响台风强度,但造成台风中心气压下降幅度不大,6 h内台风中心气压减弱约3.9 hPa。海面热量通量和海面风速与SST的分布都有良好的相关性:在SST变化为正值的暖水区,感热通量和潜热通量都是一个正的通量分布的极值区,并有风速极大值区域存在;在台风右侧相应的冷却区,则存在着负的通量异常和风速极小值区域。

Numerical Study on the Effect of Variations in Sea Surface Temperature on Intensity of Typhoon Haitang

The effect of variations in sea surface temperature(SST) on typhoon intensity is studied by making a numerical simulation of Typhoon Haitang for 5 days.Compared with the NCEP monthly mean SST data,the TMI/AMSR-E SST data are ingested into the mesoscale atmospheric model to study the effect of daily variations in SST on the track and intensity of Typhoon Haitang.It is shown from the study results that the typhoon track and intensity simulated by the experiment with daily varying SST are generally good,that is,the simulated typhoon track is not sensitive to the variations in SST,and the variations in typhoon intensity are dependent not only on the magnitude of SST cooling range caused by typhoon migration but also on the relative position of SST cooling area.In the intense development process of Typhoon Haitang,the effect of cooling area on the right of typhoon center on typhoon center air pressure was slight,and the SST cooling area began to affect the typhoon intense after the intense typhoon development,but the decrease in typhoon center air pressure was small,and the typhoon center air pressure was reduced by about 3.9 hpa within 6 hours.The sea surface heat fluxes are closely related to the sea surface wind speed and SST distributions,the positive extreme areas of sea surface heat fluxes and wind speed were distributed in the warm water area with positive SST variations,and the negative extreme areas of sea surface heat fluxes and wind speed were distributed in the SST cooling area on the right of typhoon.