大气中低频重力波指数与西南低涡发展及其暴雨的关系

THE RELATIONS BETWEEN THE INDEX OF LOW-FREQUENCY GRAVITATIONAL WAVE AND HEAVY RAIN PROCEED FROM DEVELOPMENT OF SOUTHWEST VORTEX

采用低频重力波指数法，对西南低涡发展演变及其暴雨强度、落区进行了诊断分析和预测。结果指出：（１）低频重力波指数Ｃｐ，Ｃｉ对西南低涡的发展及其暴雨强度、落区都有一定的预测意义，其预见期可达２４小时以上；（２）低频重力波指数随时间变化与西南低涡发展有较好的对应关系；（３）低频重力波指数的大小与西南低涡暴雨强度相联系；（４）西南低涡暴雨落区通常发生在Ｃｐ，Ｃｉ指数的最大负值区内和Ｃｐ等值线梯度最大的区域。

Based on the index method of low-frequency gravitational wave,diagnosis and forecast on the development of southwest vortex,intensity and area of heavy rain are discussed in this paper. The main results are as follow: (1) Development of SW vortex and heavy rain caused by SW vortex in the future 24 hours can be forecasted by the index of low-frequency gravitational wave ( C * p and C * i ). (2) There is correspondent relation between the variation of index of low-frequency gravitational wave with the time and development of SW vortex. (3) The values of index of low-frequency gravitational wave is also relating to the intensity of heavy rain proceed from SW vortex. (4) The area of heavy rain usually occurs in maximum negative areas of the index C * P,C * i and maximum gradient areas of C * p isoline.