Tropical Cyclone Initiation by the Tropical Upper Tropospheric Trough
HAWAII UNIV HONOLULU DEPT OF METEOROLOGY
Pagination or Media Count:
Improved satellite observations and an increased quantity of aircraft wind observations are meshed for case studies to modify the earlier synoptic model of tropical cyclone initiation by the Tropical Upper Tropospheric Trough TUTT. The major modification is in the vertical linkage between the upper and lower cyclonic systems. In the previous model Sadler, 1967 it was proposed that the surface system resulted from a sloping downward penetration of the strong TUTT cell and, due to the slope, the surface disturbance was properly positioned under the upper divergence for intensification. These current studies show that the TUTT cell does not penetrate into the near surface layer but that the surface disturbance is induced by the upper divergence to the east of the TUTT cell and the two systems are initially separated by some 300 to 500 km. The better observations also permit a more detailed description of the upper circulation patterns to show how the convection associated with the intensifying surface system kills the parent TUTT cell.