通过2007年陕西两次区域性大暴雨的分析发现,台风远距离的影响作用明显。在对流层中低层,台风西行发展和加强时,台风低压的东侧或东北侧的风场出现显著增强现象,为暴雨区输送大量能量和提供充沛的水汽。台风在海南附近时,其径向特征表现明显,大暴雨出现在秦岭以南;台风在台湾附近时,其纬向特征表现明显,大暴雨出现在秦岭以北。垂直运动分析表明,台风低压系统的存在、维持、发展和加强对副热带高压有一定的维持、加强作用,有利于强降水的形势能够稳定和维持。
The long distance influence of the typhoon on two regional big heavy rains in Shaanxi in 2007 is evident. The wind field significantly strengthens when the westward typhoon is developing and strengthening which transports plenty of energy and provides abundant water vapor. Typhoon presents obvious longitudinal characteristic when it is near Hainan province and big heavy rain occurs in the southern area of Qinling Mountain. Typhoon presents lati- tudinal characteristic when it is near Taiwan province and big rain occurs in the northern area of Qinling Mountain. Ba~d on analysis of vertical movement the existence, maintenance and development of typhoon low-pressure system makes the subtropical high pressure maintained and strengthened which is beneficial in stabilizing and keeping heavy rain synoptic pattern.