0103号和0104号台风暴雨过程的螺旋度和位涡分析

利用螺旋度和位涡对 0 10 3号和 0 10 4号台风过程进行分析 ,结果表明 :暴雨位于正螺旋中心右侧 ,当负螺旋度转为正螺旋度并增加时 ,将出现台风低涡暴雨 ,当螺旋度减小并由正转负时 ,暴雨也趋于结束 ;正螺旋度中心位于登陆台风移动路径的前方。台风中心上空对应正的干位涡 (PV)大值中心 ,而湿位涡 (MPV)与暴雨的关系更为密切 ,70 0 HPA以下 MPV为负 ,70 0 HPA以上 MPV为正 ;台风低涡暴雨位于正负 MPV2中心之间的低值区

Study on Helicity and Potential Vorticity of No. 0103 and No. 0104 Typhoon with Torrential Rainfall

Helicity and potential vorticity were applied to analyzing No.0103 and No.0104 typhoon processes. The result shows that the rainstorm took place in the right area of the positive maximum center of helicity, and when the negative helicity turned to the positive helicity and increased, typhoon low vorticity rainstorm will also take place. While vorticity decreased and turned from the positive to the negative, the rainstorm tended to end. Moreover, center of the positive helictity was located ahead of the moving route of the landing typhoon. There is a positive PV center over the center of typhoon, and the wet potential vorticity (MPV) is closely related to rainstorm. MPV under 700HPA is negative and that above 700HPA is positive. Torrential rainstorm of typhoon is located on the areas of minimum value between the positive and negative center of MPV2.