摘要: An observational study of tropical cyclone genesis was made by compositing western Pacific rawinsonde data with respect to both pre-typhoon and non-developing cloud clusters. The size,intensity,and mean vertical motion of the dist... 展开 An observational study of tropical cyclone genesis was made by compositing western Pacific rawinsonde data with respect to both pre-typhoon and non-developing cloud clusters. The size,intensity,and mean vertical motion of the disturbances which eventually evolved into typhoons were similar to the non-developing clusters which did not intensify. However,four primary physical differences between pre-typhoon and non-developing clusters are found: (1) The low-level relative vorticity with the pre-typhoon clusters was about twice as large. (2) The non-developing clusters were cold-core in the 500-800mb layers while the pre-typhoon clusters were slightly warm-core at these levels. (3) The ventilation (non-divergent flow through the cluster area) which advects heat energy away from the cluster was larger with the non-developing clusters in the warm-core layers (200-500mb) and ventilation of moisture out of the non-developing clusters was significantly larger at lower tropospheric levels (500-900mb). (4) The outflow in the upper troposphere was similar in magnitude but markedly anticyclonic with the pre-typhoon clusters. 收起